Cross-Layer Security for Resilient Cyber-Physical Systems

Sangjun Kim DGIST 2022 국내박사

Cyber-physical system (CPS) is an integration of physical systems in the real world and control software in the cyber world. The physical systems and the control software are connected by wired and wireless networks, which enhance the connectivity of each CPS component more than conventional embedded systems. However, due to the enhanced connectivity, malicious attacks can be launched through the networks, which degrade the control performance or destabilize the physical systems. In particular, the real-time interactions between the physical systems and networks are the main target of the attacker. The main topic of this dissertation is the design of resilient cyber-physical systems against the cross-layer cyber-physical attacks that target the interactions between the physical systems and networks. Cross-layer cyber-physical attack is defined as the attack having different attack media and attack target, which correspond to the attack access location and disruption object of the attacker, respectively. Unlike conventional physical attacks and network attacks, the cyber-physical security strategies against the cross-layer cyber-physical attacks must consider both aspects of the physical systems and the networks. Furthermore, cyber-physical security strategies detect cyber-physical attacks and have resiliency. By cyber-physical attacks, the physical systems are disrupted in a timely manner; therefore, the cyber-physical security strategies must provide control performance recovery to mitigate the physical impact of the attacks in real-time. As a countermeasure for the cross-layer cyber-physical attacks targeting physical systems, we propose a resilient CPS framework with a holistic network-wide approach. The proposed CPS framework has three resilient functions; attack detection, attacker isolation, and path recovery. When the cyber-physical attack is launched, distributed network devices detect the cyber-physical attacks with control-theoretical attack detection algorithms and notify a network manager of the attack. After detection, the network manager estimates the location of the attacker and isolation the attacker on the networks. Finally, the network manager reconstructs the communication path between the physical systems and computing systems to reestablish feedback control loops between them, which recover the control performance of the physical systems from the physical damage by the attacks. We consider pole-dynamics attack as an example of sophisticated cross-layer cyber-physical attacks and implement the proposed CPS framework with software-defined networking (SDN). By implementing a testbed, we show that the proposed CPS framework can ensure the safety of the physical systems in real-time. For the cross-layer cyber-physical attacks targeting networks, we first propose a novel cyber-physical attack named disturbance-induced denial-of-service attack. The proposed attack consumes limited network resources by injecting physical disturbances to the physical systems with an aperiodic control strategy. The attack-induced delays interfere with transmissions of control-related packets for the feedback control, which degrades the control performance or destabilizes the physical systems. To ensure the stability of the physical systems under the novel cyber-physical attack, we propose a resilient CPS framework consisting of a detection algorithm and two attack mitigation algorithms. The proposed CPS framework detects the DIDoS attack with a disturbance estimator using control input signals, state measurements, and the physical system model. In addition, the controller gain tuning and access point (AP) handover algorithms mitigate the impact of the DIDoS attack by diminishing network utilization of the physical systems. By conducting simulations, we evaluate the impact of the proposed attack and the resiliency of the proposed CPS framework. Simulation results for the physical impact show that the proposed attack drastically increases transmission delays for control input signals, which destabilizes not only the compromised physical systems but also the benign physical systems. In addition, the controller gain tuning and AP handover algorithms can reduce network delays by reducing the traffic generation of benign physical systems, and migrating networks of some physical systems, respectively. From a realistic CPS viewpoint, we design a resilient cyber-physical security strategy, where we consider communication-based train control (CBTC) systems that consist of trains on the railway, ground facilities, and wired/wireless networks to connect them. Through the networks, the malicious attacker launches the cyber-physical attacks targeting CBTC systems, which cause significant traffic accidents, such as derailment and train collisions. For the control command manipulation on the network, we show that the cross-layer cyber-physical attack on the wireless networks can cause train collision accidents. As a countermeasure of the cyber-physical attack, we implement the resilient CPS framework based on the SDN, which provides an attack detection and an emergency braking function to prevent train collisions in real-time. We evaluate the safety performance of the proposed CPS framework in a realistic CBTC testbed, where the experimental result shows that the proposed framework executes the emergency braking function within 2.5 s, which is short enough time to ensure the safety of the CBTC systems against the cyber-physical attack causing the train collision accidents. 사이버물리시스템은 현실세계의 물리시스템과 사이버공간의 제어소프트웨어의 결합으로 정의된다. 사이버물리시스템의 네트워크는 물리시스템들과 소프트웨어 간의 실시간 상호작용을 지원하며 기존 임베디드시스템 보다 확장된 연결성을 제공한다. 하지만, 사이버물리시스템에서 네트워크 도입으로 향상된 연결성은, 악의적인 공격자의 네트워크를 통한 사이버물리공격 인가를 허용하며, 이는 사이버물리시스템의 제어 성능을 악화시키고 심지어 물리시스템을 불안정한 상태를 초래한다. 특히, 물리시스템과 네트워크 간의 실시간 상호작용은 사이버물리공격자의 주요 공격 대상이다. 이에 대해, 본 학위 논문의 주요 주제는 물리시스템과 네트워크간의 상호작용을 대상으로 하는 계층간 사이버물리공격에 대응하는 보안기법과 자율복원 사이버물리시스템을 설계하는 것이다. 계층간 사이버물리공격은 공격자의 접근위치를 의미하는 공격매체와 공격의 파괴목표 개체를 의미하는 공격 대상이 상이한 사이버물리공격으로 정의된다. 기존의 물리적 공격 또는 네트워크 공격과 달리, 계층간 사이버물리공격에 대한 보안기법들은 물리시스템의 관점과 네트워크 관점을 모두 고려하여 설계되어야 한다. 또한, 사이버물리 보안기법들은 공격 검출뿐만 아니라 공격에 의한 물리적 피해를 실시간으로 회복하는 자율복원능력을 포함하여야 한다. 물리시스템을 공격대상으로 가지는 계층간 사이버물리공격의 대응책으로서, 네트워크관점에서의 자율복원 사이버물리시스템 프레임워크를 제안한다. 제안하는 프레임워크는 공격 검출, 공격자 격리, 경로 복구 기능을 포함한다. 네트워크상에 분산되어 설치된 네트워크 장비들이 제어이론 기반의 공격 검출 알고리즘을 보유하고 있으며, 사이버물리 공격이 인가되었을 때, 네트워크 장비들은 실시간으로 공격을 검출하고 네트워크 매니저에게 보고한다. 공격 검출이 수행된 이후, 네트워크 매니저는 공격자의 침입위치를 추정하고, 공격자를 네트워크로부터 격리한다. 마지막으로, 네트워크 매니저는 공격자 격리에 의해 소실된 물리시스템과 컴퓨팅 장비간의 통신 경로를 복구하며, 이는 공격에 의한 물리시스템의 피해를 복구한다. 가장 정교한 계층간 사이버물리공격 중 하나인 극 역학 (pole-dynamics) 공격에 대해, 소프트웨어 정의 네트워킹 (software-defined networking) 기반의 제안한 프레임워크가 물리시스템의 안정성을 보장할 수 있음을 실험을 통해 검증한다. 네트워크를 공격대상으로 가지는 계층간 사이버물리공격을 대상으로, 사이버물리시스템의 새로운 취약점 중 하나인 외란 기반의 서비스 거부 공격을 제안한다. 제안된 공격은 비주기 제어기법을 사용하는 물리시스템을 대상으로 외란을 인가하여 제한된 네트워크 자원을 고갈시킨다. 제안된 공격에 의해 유발된 전송지연은 제어정보가 포함된 패킷의 전송을 방해하며, 이는 물리시스템의 제어성능을 저하시키거나 물리시스템을 불안정하게 만든다. 제안된 공격에 대한 대응기법으로서, 공격 검출 알고리즘과 두 가지 공격 완화 알고리즘을 포함하는 자율복원 사이버물리시스템 프레임워크를 제안한다. 제안된 프레임워크는 제어 입력 신호와 물리시스템의 상태정보, 물리시스템의 모델을 활용한 외란 추정 기법을 사용하여 공격을 검출한다. 또한, 제어기 이득 조율 알고리즘과 액세스 포인트 변경 알고리즘은 네트워크 사용량을 줄여 제안된 공격의 영향을 감경시킨다. 공격 영향에 대한 시뮬레이션 결과는 제안된 공격이 컴퓨팅 장비로부터 물리시스템으로 전송되는 제어입력신호에 대한 전송지연을 증가시켜 물리시스템을 불안정 시킴을 입증하며, 이는 제안된 공격이 외란이 인가된 물리시스템 뿐만 아니라, 외란의 영향이 없는 물리시스템도 불안정한 상태가 되게 할 수 있음을 보인다. 또한, 제어기 이득 조율 알고리즘과 액세스 포인트 변경 알고리즘은 각각 외란의 영향이 없는 물리시스템의 네트워크 사용량 감소와 네트워크 변경을 통해서 기존 네트워크의 전송 지연을 감소시켜 통해 물리시스템의 안정성을 보장함을 시뮬레이션을 통해 검증한다. 다수의 열차와 지상 제어시스템이 유무선네트워크로 연결된 통신기반 열차제어시스템을 대상으로 실질적인 사이버물리시스템의 관점에서의 자율복원 가능한 사이버물리보안 기법을 제안한다. 악의적인 공격자는 네트워크를 통해서 통신기반 열차공격에 대한 사이버물리 공격을 인가할 수 있으며, 이는 열차의 탈선이나 충돌을 유발할 수 있다. 무선네트워크상에서 전달되는 제어입력의 변조를 통해, 공격자가 열차의 충돌을 유발하는 계층간 사이버물리공격이 인가될 수 있음을 보인다. 계층간 사이버물리공격의 대응책으로서, 소프트웨어 정의 기반 네트워킹 기술을 활용한 자율복원 사이버물리시스템 프레임워크를 제안하였으며, 이는 사이버물리 공격의 검출과 열차 충돌 방지를 위한 긴급정지 기능을 제공한다. 실제 환경과 유사한 테스트베드 환경에서 실험을 진행한 결과, 제안하는 자율복원 프레임워크가 열차의 충돌을 방지하기에 충분히 짧은 시간인 2.5초 이내에 긴급 정지 기능을 제공함을 입증한다.

Learning-Enabled Cross-Layer Design for Cyber-Physical Production Systems

Sihoon Moon DGIST 2024 국내박사

A COUPLED PHYSICAL-BIOLOGICAL MODEL FOR THE CLYDE SEA

Lee, Jae Young Napier University 2002 해외박사

An integrated physical-biological model has been developed for the study of seasonal changes of chlorophyll and related nutrient concentrations in the Clyde Sea. The physical (transport) model includes an estuarine circulation and intermittent deep-water renewal. Along with horizontal exchanges including advection flows and tidal exchanges, the physical model was forced by surface heat-exchanges, fresh-water buoyancy, and turbulent energy inputs from wind, tide and internal waves. With pseudo-weather forcing and real fresh-water data, the physical model predicted realistic features of seasonal changes of temperature and salinity in the region. The physical model also predicted strong seasonal cycles of intermittent flows entering into the deep water of the Arran Deep basin. The biological model applied the 'Microplankton-Detritus (MPD)' concept, but with two different microplankton compartments, nutrient silica dynamics, and shear-generated phytodetritus from an aggregated-'diatomy' microplankton. The model showed realistic seasonal patterns of chlorophyll and nutrient concentrations and of the succession of microplankton dominance. It was found that irradiance was the main limiting factor for microplankton growth in the surface mixed layer throughout most of the year. However, in some cases, the light limitation might have resulted from averaging of the mean irradiance over a 20 m surface layer in the physical model. The coupled model was also used to predict primary production, carbon fluxes into the deep basin, and nutrient budgets, especially for nitrogen. It was found that gross primary production in the Clyde Sea was consumed mainly by respiration, and that fast-sinking phytodetritus played an important role in carbon losses to the bottom boundary. Atmospheric nitrogen, which contributed about 13 % of net nitrogen flux input, did not have significant effects on biological model results, but it was found that it could be a new nutrient source for plankton growth at the surface layer especially in summer. The major nitrogen flux into the water of the Clyde Sea was from rivers, and the largest net export flux was by sedimentation. The model was also applied to study the response of the Clyde Sea to a global warming scenario. Due to an increase of precipitation in the global warming scenario, the intermittent advection flow into the deep water of the Arran Deep was increased, and resulted in longer periods of stagnation. Although the model generally well re-produced observations from the PROFILE campaign (1993 - 1994), there were not enough data to validate the model. With more observations and the inclusion of denitrification process in a new benthic model, the coupled model could be used as a management tool to investigate effects of perturbation induced by nature or by humans.

A Study on Effects of Childhood Physical Activity Attitudes and Level of Physical Activity Participation on Dance Major Selection Motivation and Dance Continuation Intention among Dance Major Students in China

양청 세한대학교 대학원 2024 국내박사

This study aims to analyse the effect of childhood physical activity attitudes, level of physical activity participation, dance major selection motivation, and dance continuation intention among university students majoring in dance in China. To achieve this purpose, a survey was conducted among students majoring in dance at two universities, Xi'an Overseas University and Shaanxi Normal University. A total of 510 responses were collected and empirically analyzed with a sample size of 500 after excluding inappropriate responses. The findings were as follows. First, differences in demographic variables among Chinese dance major students showed significant differences in some sub-factors based on gender and age. Male students had significantly higher mean childhood physical activity attitudes than female students. Dance major selection motivation showed significant differences in some sub-factors according to gender, grade, age, and dance experience. Dance continuation intention showed significant differences in some sub-factors according to gender, grade, age, and dance experience. Second, higher childhood physical activity attitudes were associated with higher level of physical activity participation such as walking time and moderate exercise time; higher childhood physical activity attitudes were associated with higher Dance Major Selection Motivation and Dance Continuation Intention; male university students had higher levels of enjoyment, self-confidence, and preference in childhood physical activity attitudes; and higher dance major selection motivation was associated with higher dance continuation intention. Third, gender, dance experience, and childhood physical activity attitudes were the factors that influenced the total score of dance major selection motivation, and the influence explained 38.4%, which was statistically significant. Gender, dance experience, and childhood physical activity attitudes influenced intrinsic motivation, while gender and physical activity attitudes influenced extrinsic motivation. Fourth, among dance continuation intention, gender, dance experience, and childhood physical activity attitudes were found to influence predisposing intention to persis, while age and physical activity attitudes were found to influence enabling intention to persist. Among Dance Continuation Intentions, gender, dance experience, and physical activity attitudes were found to be influential factors for intensified continuation. This study found that Xi'an university students' childhood physical activity attitudes and level of physical activity participation influenced their dance major selection motivation and their dance continuation intention. Therefore, more attention should be paid to cultivating students' positive physical activity attitudes and consistent activity levels in dance curricula from childhood, and enhancing university students' dance major selection motivation and their dance continuation intention. This is a quantitative, questionnaire-based study among undergraduate students in the dance departments of Xi'an Overseas University and Shaanxi Normal University in Shaanxi Province, China. In future research, it is necessary to conduct a study with a wider range of university dance students in different regions using different analysis methods. In addition, it is hoped that follow-up studies will be conducted with various variables and research models. keywords: Dance major, Childhood Physical Activity Attitudes, Level of Physical Activity Participation, Dance Major Selection Motivation, and Dance Continuation Intention

男·女 高等學生의 體育學習에 對한 關心度 調査 硏究 : 木浦市 男·女高等學校 學生을 中心으로

이강청 朝鮮大學校 敎育大學院 1994 국내석사

Today. the physical education must satisfy the student's physical. mental, sentimental, dad social desires. And it must help each student's. Possibilities of growth. So it is very important for administrators and teachers to know the physical activities. Therefore. in this thesis we study the physical activities and the interests about physical education in high school. And we propose the teaching methods of physical education for administrators and teachers. The 8 high school 389 student's in Mokp'o City attended in this investigation. We have the Conclusion as followings : 1) The student's favorite and proficient sports activities are basketball, soccer, baseball. in the case of boys, basketball, tennis, swimming in the case of girls. 2) The proper physical activities make a good effect to study of other curricula. 3) The student's interest of physical education class is very high and they want to choose the physical activities in the class. 4) The school's physical facilities are needy. The student's want to install many facilities. 5) The boys are more interested in physical activities than girls. Therefore, physical education of girls must be improved in not only teaching methods also physical activities.

水田放飼した合鴨による接觸刺激ならびに中耕濁水が手稻生産に及ぼす影響

高秉大 鹿兒島大學 2002 해외박사

合鴨農法は水田生態系內での稻作と畜産の有機的結合により無農藥の水稻生産が可能であり, その技術的效果についても除草, 驅蟲ならびに肥料效果等について明らかにされてきている. しかしながら, 合鴨の水稻への接촉刺激ならびに中耕濁水效果については, その實驗手法の難しかしながら, 未だた科學的な裏づけはなされていなかつた. 本論文は, 合鴨による水田內での水稻への接촉刺激ならびに中耕濁水が水田環境ならびに水稻生産に及ぼす效果について. その實驗手法に創意工夫を응らし, 3年間にわたる反復試驗により再現性の高い實증を試みたものである. 得られた成果は以下のとおりである. 1. 合鴨の接觸촉刺激が稻生育と收量に及ぼす影響 合鴨による接촉刺激は水稻の草丈の伸長生長を著しく抑制するが, 有效莖數, 葉面積の增加ならびに根張りの促進が示唆された. また, 下位部間の直經および稈の挫折抵抗力を大きくし, 倒伏輕減效果が示唆された. さらに1株穗數, 登熟步合および反當たりの靑精인收量は增加することが明らかとなった. なお, 合鴨の接촉刺激による生長抑制の一因が生長ホルモンであるエチレンガ關與しているものと推察きれるが, 實驗圍場での本體の測定が難しく, 今後の檢討課題である. 2. 合鴨の中耕濁水が水田環境に及ぼす影響 合の中耕濁水により潛漑水のpHは平均7.4前後で推移し, 稻生育の適正範圍內にあり, 溶存酸素濃度は合鴨放飼初期に一時增加するが, その後水稻の生育が進むにつれて急速に減少した. 浮遊物質濃度は合鴨放飼期間中邊化しないことが示唆きれた. なお灌漑水中のアンモニア態窒素およびリン酸濃度は低下することが示唆された. 3. 合鴨の中耕濁水が稻生育および收量に及ぼす影響 合鴨の中耕濁水は水稻の草丈および下位節間の伸長生長を著しく促進するが, 有效莖數は增加させないことが明らかとなった. また, 稻地上部と根の乾物重量は增加し, 稈長, 穗長は長くなり, 出穗後の稻生育を促進させた. 稈の直徑と挫折抵抗力は增加したが, 倒伏輕減效果は認められなかった. 1穗○花數, 登熟步合および千粒重は著しく增加し, 最終的には稻收量の增加をもたらすことが明らかにされた. 本論文は合鴨農法の技術的效果の中で, 未だに科學的な裏づけがなされていなかった合鴨の接촉刺激ならびに中耕濁水效果について, 3年間にわたる周到な反復試驗により初めて解明したものであり, 今後の環境調和型農業としての合鴨農法の普及推進に寄與するところ大であり, 學位論文として十分な價値を有するものと認められた. Major positive effects of integrated rice and duck farming system include weeding, pest control, manuring, physical stimulation to a rice plant, and intertillage and muddying by the animals. Some reports on the advantageous effects of weeding, pest control and manuring are available, whereas, there have been little scientific and clear findings in regard to the effects of the physical stimulation, intentillage and muddying by free-ranging Aigaamo ducks. Therefore, this study was undertaken to determine the influence of physical stimulation by the ducks on rice plant growth and yield, and to the effect of intertillage and muddying on paddy field environment, soil physics and chemistry, and rice plant growth and yield, and to clarify the significance of the activities of the animals in the integrated rice-duck farming system. 1. Effect of physical stimulation by the ducks on rice growth and yield This experiment was conducted to clarify the influences of the physical stimulation by free-ranging Aigamo ducks (Chinese native ducks) on rice plant growth and yield. The experimental paddy field was consisted of a physical stimulation plot (PS) and a non-physical stimulation plot (NPS), i.e. the 40 hills were randomly selected and each hill was enclosed with a wire netting. Twelve ducklings at 8 days of age were free-ranged in the experimental paddy plots (4.0a) on the 9th day after the transplantation of the rice plant. The length of the rice plant in the PS plot was significantly shorter than that in the NPS plot following the 30th day after introducing the Aigamo ducks into the paddy field (P<0.05). In contrast, the number of tillers per hill significantly increased in the PS plot (P<0.05). The leaf area of maximum tiller number stage and heading stage of the rice plant were significantly increased by the physical stimulation with the Aigamo ducks, also the shoot and root fresh and dry weight of the heading stage of rice plant were markedly increased in the PS plot than that in the NPS (P<0.05). The number of roots when the ripening stage more in the PS plot than that in the NPS plot (P<0.05), but the chemical composition of the rice plant was not changed by the physical stimulation of the animals. After heading of the rice plant, the culm length in the PS plot was significantly shorter than that in the NPS plot, however the length of the panicle significantly increased in the PS plot (P<0.05). The number of productive tillers, the fresh weights of the culm and ear of the rice plant were significantly increased by the physical stimulation of the rice plant by the animals (P<0.05). The dry weight of the top part of rice plants in the PS plot was significantly heavier than that in the NPS plot (P<0.05), but not in the root of the rice plant. The percentage of starch accumulation and leaf number of the rice plant was significantly higher in the PS plot (P<0.01). The length of the 4th internode was markedly shorter and the diameter of the 3rd and 4th internode was larger in the PS plot (P<0.05). Therefore, the lodging resistance of the rice plant in the PS plot was significantly larger than that in the NPS plot (P<0.05), and the lodging index showed lower value in the PS plot (P<0.05). The number of ears, ripening grains and yield crops per hill of the rice plant in the PS plot were significantly more than those of the NPS plot (P<0.05). Therefore, the yield of each rice plant per 10a was significantly increased in the PS plot (P<0.01). These results indicate that physical stimulation to a rice plant by free-ranging Aigamo ducks promoted an increase in dry weight of the ground parts of a rice plant including the number of tillers per hill, leaf area, panicle length, culm and ear weight, and finally results in an increased rice yield, though the plant length and the internode elongation were not observed to increase. 2. Effect of stocking density on duck behavior pattern, rice plant growth and yield under a rice-duck farming system. This experiment was carried out to elucidate the optimum density of free-ranging ducks in a rice-duck farming system in terms of effects on duck behavior, growth and yield of rice plants. Four identical paddy fields were used for this experiment, with varying stocking densities (6, 9, 12 and 15 birds per plot. respectively). Ducklings at eight days of age were free-ranged in each plot (4.0a) on the 9th day after the transplantation of rice plants. Foraging, moving, resting, diving and pecking behaviors of the ducks were observed twice (12hr in the daytime a day) during the experimental period. Rice plant growth arid yield were also examined. The foraging and moving time of the free-ranging ducks in paddy fields tended to be longer in the 12-bird plot. The working time including foraging and moving time was significantly longer in the 12-bird plot than others (P<0.05). The resting time was significantly longer in the 9- and 15-bird plots than in the 12-bird plot (P<0.45). The frequency of moving behavior for 6 hours during the daytime in the 15-bird plot tended to be lower than that in others, but this difference was not statistically significant. The amount of diving and pecking behavior in the 9-bird plot was significantly larger than that in others, and pecked hills tended to increase with increasing stocking density. After 30 days, the length of rice plants tended to be significantly shorter in the 12- and 15-bird plots compared to the others. The number of tillers per hill in the 12- and 15-bird plots was significantly more than those of the 6-bird plot (P<0.05). The contents of dry matter, crude protein and neutral detergent fiber of the rice plant in the ripening stage were higher in the 12- and 15-bird plots than others, however the other chemical compositions were not significantly different among the treatments. The culm length of rice plants was significantly shorter in the 12- and 15-bird plots than others, but stocking density did not affect the panicle length. The root dry weight of the rice plant was increased with increasing density, but there was no such increase in the ground part of the rice plants. The number of panicle, ripening grains and crop yield per hill of rice plants in the 12-bird plot were significantly higher than those of the 6- and 9-bird plots. Therefore, the yield of each rice plant per 10a increased in the order of 12-, 9-, 15- and 6-bird plots. These results suggest that the higher the stocking density, the more inhibited the elongation growth of the rice plant, but the number of tillers per hill and root dry matter of the rice plant are increased. Moreover, the lodging resistance and the yield per 10a of the rice plant were elevated with increasing stocking density except for the 15-bird plot. Although the higher stocking density resulted in promote the physical stimulation, problems such as odor from excessive manure, percentage of rice plants damage and increase of feed requirement were observed in this study. Therefore, the optimum stocking density is suggested to be 30 birds per 10a. 3. Effect of manual physical stimulation to the rice plant on the rice growth and yield in paddy fields, in imitation of pecking behavior of ducks. This study was conducted to prove the relationship between simulated pecking behavior of Aigamo ducks on rice plants and the rice growth and yield under the rice-duck farming system. The experimental paddy field consisted of two plots, a physical stimulation plot (PS) and a non-physical stimulation plot (NPS). Twice a day, 10a.m. and 5p.m., the manual physical stimulation to the rice plant was given by gently hitting the bottom part of the plant (100 times) with a stick and by stroking its top part (30 bouts) with a duster. After four weeks. the plant length from the PS was significantly shorter than that of the NPS (P<0.05), but there were no significant differences in the number of tillers, degree of hill spread, stem thickness and leaf area of the rice plant. During the maximum tiller number and heading stage of the rice plant, the top dry weight of the plant in the PS was significantly less than that in the NPS (P<0.05), whereas its root dry weight was significantly greater heading and ripening stage of the rice plant (P<0.05). The length of the 3rd and 4th internode elongation of the bottom part of the rice plant was significantly shorter in the PS than in the NPS (P<0.05). The height of gravity center of the rice plants was also significantly lower in the PS (P<0.05). The lodging resistance of the rice plants in the PS was higher, but the lodging index was smaller (P<0.05). Both the number of panicles and the weight per 1000 grains were not significantly different between the treatments. The number of spikelets per panicle of the rice plants in the PS was significantly less than that in the NPS (P<0.05), however the percentage of ripened grains was significantly higher in the PS (P<0.05). The yield of paddy rice per unit area was not different between the treatments. The results imply that physical stimulation to rice plants inhibited not only the plant length and internode elongation of the bottom part, but also it affected the root dry weight of the plants. Though the lodging resistance and shoot growth after heading of the rice plant were elevated by the physical stimulation, the rice yield components including panicle number, weight per 1000 grains and paddy rice yield were not affected. 4. Effect of intertillage and muddying by the ducks on paddy field environment and soil physics and chemistry. The present study was carried out to determine the effect of intertillage and muddying by free-ranging Aigamo ducks on paddy field environment, soil physics and chemistry. Two paddy fields comprised of the muddying (without physical stimulation to a rice plant by the ducks) and the control plots (no ducks) were used for this experiment. As for the muddying plot, 50 hills ware randomly selected and each hill was fenced with a wire net in order to prevent the ducks from stimulating rice plants physically. The variation in irrigation pH was smaller in the muddying plot than the control, showing around 7.4, and the value varied within a reasonable range for the growth of rice plant. Dissolved oxygen was significantly higher (P<0.05) in the muddying plot than the control during the first half period after introducing the ducks, and then it was rapidly decreased as the rice plants grew up. The contents of the suspended soil and turbidity in irrigation water were not changed over the free-ranging period, but NH3-N and P2O5 were decreased by intertillage and muddying by the ducks. There were no differences in both the soil physics and chemistry between the muddying plot and the control during and after finishing of the free-ranging period. These results indicate that intertillage and muddying by Aigamo ducks resulted in a small variation in irrigation pH, and reduced the dissolved oxygen and P2O5, although the soil physics and chemistry were not changed. 5. Effect of intertillage and muddying by the ducks on rice growth and yield in the paddy field. The present study was carried out to determine the effect of intertillage and muddying by free-ranging Aigamo ducks on rice plant growth and yield. Two paddy fields consisting of the muddying (without physical stimulation to a rice plant by the ducks) and the control plots (no ducks} were used for this experiment. As for the muddying plot, 50 hills were randomly selected and each hill was fenced with a wire net in order to prevent the ducks from stimulating rice plants physically. The length of the rice plant was significantly longer (P<0.05) in the muddying plot than the control, but the number of tillers increased in the control plot during the second half period (P<0.05). The shoot and root dry weight of the rice plant tended to increase in the muddying plot than the control, and the leaf area and root number of rice plant in the ripening stage was significantly increased in the muddying plot (P<0.05). The length of culm, panicle, the 3rd and 4th internode of rice plant after heading were significantly longer in muddying plot than the control (P<0.05). Moreover, the diameter of 3rd and 4th internode in the muddying plot was remarkably larger than the control (P<0.05). The lodging resistance of the rice plant in the muddying plot was significantly larger (P<0.05) compared with the control, but did not affected the lodging index. The spikelet number per panicle, the percentage of ripened grain and weight per 1000 kernels in the muddying plots were significantly (P<0.01) more than the control. Therefore, the paddy rice yield per 10a was significantly increased in the muddying plots (P<0.01). These results indicate that intertillage and muddying by the ducks promoted the internode elongation of ground part of the rice plants, and increased the yield components such as the number of spikelet per panicle, percentage of ripened grains and 1000 grains weight of rice plants. 6. Effect of manual physical intertillage and muddying to the irrigation water and soil on the paddy field environment and soil physics and chemistry, in imitation of the duck behavior This study was conducted to prove the effect of manual physical intertillage and muddying to the irrigation water and soil on the paddy field environment, soil physics and chemistry, in imitation of the duck behavior The experimental paddy fields consisted of two plots, i.e. the muddying (intenillage and muddying) and the control plot (non intertillage and muddying) were used for this study. The manual intertillage and muddying to the paddy field water and soil were given twice a day, at 10 a.m. and 5 p.m. by gently plowing the bottom part of the soil (10 times) with a hoe and by stirring the paddy field water (5 minutes) with a hand. The variation in irrigation pH was smaller in the muddying plot than the control, and the pH value varied within a reasonable range for the growth of rice plant, However, there was no significant difference in pH between the muddying plot and the control. Dissolved oxygen was significantly lower (P<0.05) in the muddying plot than the conn-ol during the second half period after introducing the ducks, and it rapidly decreased as the rice plants matured. The contents of the suspended soil and turbidity in irrigation water were not changed over the manual physical treatment period, but NH3-N and P2O5 were significantly decreased by physical intertillage and muddying (P<0.05). There were no differences in both the soil physics and chemistry between the muddying plot and the control over the experimental period. These results indicate that physical intertillage and muddying did not affect the irrigation pH, but decreased the dissolved oxygen. The irrigation NH3-N and P2O5 also decreased in muddying plot, though the soil physics and chemistry were not changed. 7. Effect of manual physical intertillage and muddying to the irrigation water and soil on the rice growth and yield in paddy fields, in imitation of the duck behavior This study was undertaken to prove the effect of manual physical intertillage and muddying to the irrigation water and soil on the rice growth and yield in paddy fields, in imitation of the duck behavior The experimental paddy fields consisted of the muddying (intertillage and muddying) and the control plot (non intertillage and muddying) were used for this study. The manual intentillage and muddying to the paddy field water and soil were given twice a day at 10 a.m. and 5 p.m. by gently plowing the bottom part of the soil (10 times) with a hoe and by stirring the paddy field water (5 minutes) with a hand. After ten days, the plant length in the muddying plot was significantly longer than that of the control (P<0.01), but there were no significant differences in the number of tillers, degree of hill spread, leaf area and stem thickness of the rice plant. The shoot and root fresh weight of the rice plants in the muddying plot were significantly heavier than that in the control (P<0.05), especially the shoot dry weight was significantly greater in the ripening stage (P<0.01). Moreover, the root dry weight in the maximum tiller number and ripening stage was significantly Larger in the muddying plot than the control (P<0.05). The length of culm was longer in the muddying plot (P<0.05) after heading of the rice plant. The diameter of the 3rd and 4th internode of the rice plant was also significantly larger in the muddying plot than in the control (P<0.05). However, muddying did not significantly affect the lodging related character such as the height of gravity center, lodging resistance and lodging index of the rice plant. The numbers of panicle and spikelet were not significantly different between the two treatments, but the percentage of ripened grains and the weight per 1000 grains of the rice plant in the muddying plot were significantly greater than that in the control (P<0.05). Therefore, the paddy rice yield per l0a was significantly increased in the muddying plot (P<0.01). The results suggest that the physical intertillage and muddying to paddy field water and soil not only promoted the length of the plant and culm but also affected the shoot and root fresh weight and dry weight of the rice plants. Moreover, it increased the paddy rice yield including the percentage of ripened grain and weight of 1000 grains. In conclusion, physical stimulation to a rice plant by free-ranging Aigamo ducks promoted the plant growth, lodging resistance and an increased rice yield, while intertillage and muddying by the ducks caused an increase in the plant length, internode elongation of the bottom part, shoot growth of the rice plants after heading, which finally improved rice yield and its yield components. Therefore, the advantageous effects of physical stimulation, intertillage and muddying by free-ranging Aigamo ducks were scientifically and convincingly verified. Key words : Aigamo ducks, Physical stimulation, Intertillage and muddying, Rice production, Rice-duck farming system.

스포츠활동 참여수준과 신체적 자기개념

김정원 全北大學校 敎育大學院 2004 국내석사

This study has an aim to examine the difference of physical self- concept university students recognize based on level of participation in sports activity and sex. This study selected general university students(men students: 103 persons, women students: 103 persons total 206 Persons) and physical-education majoring students(men students: 199 persons, women students: 190 persons total 389 persons) going on universities located in Jeollabuk-do as an object of study. This study divided those students into as followings; The general university students were divided into whether they participate in sports activity or not(participator, not participator) based on 5 step change model of unified model theory Carron, Berger(2003) applied. Physical-education majoring students were divided into levels of sports participation based on whether they are players or not (player, physical-education majoring student). The tool this study used to test was Kim, Beuong-Jun's(2001) Physical Self-Description Questionnaire in Korean version, composed of 10 sub-factors including sense of sports ability, fatness/slenderness, appearance, health, bodily activity, self-esteem, flexibility, endurance, muscular strength, and general bodily matters. This study performed two-way MANOVA with independent variable factors of sex and participation in sports activity and dependent variable factors of sub-factors of Physical self-concept based on collected materials, and established level of statistical significance as p< .05. Firstly, men students' Physical self-concept university students recognize was higher than that of women-students in the most sub-factors including sense of sports ability, fatness/slenderness, health, bodily activity, self-esteem, flexibility, endurance, muscular strength, and general bodily matters. Secondly, this study investigated university students' Physical self concept based on level of participation in sports activity. The Physical self-concept got higher when participation level in sports activity did in the sub-factors including sense of sports ability, fatness/slenderness, health, bodily activity, self-esteem, flexibility, endurance, muscular strength, and general bodily matters. Thirdly, this study investigated Physical self-concept general university students recognized. Men students' bodily self-conception was higher than that of women students in the factors including sports ability sense, fatness/slenderness, health, bodily activity, self-esteem, flexibility, endurance, muscular strength, and general bodily matters. Fourthly, This study investigated general university students' Physical self-concept based on whether they participated in sports activity or not. Participator group's Physical self-concept was higher than that of non-participator group in the factors including sense of sport ability, bodily activity.

한국체육에 YMCA 체육활동이 미친 영향

조민동 용인대학교 교육대학원 2001 국내석사

본 연구는 1903년 창설된 한국YMCA가 한국의 스포츠 도입과 보급을 통하여 민족운동 전개와 건강증진, 사회체육발달에 어떤 역할을 하였는지 고찰하여 보고 YMCA체육프로그램을 시대별로 구분하여, 한국 체육발전에 어떻게 영향을 미쳤는지를 고찰하는데 그 목적이 있다. 이러한 연구 목적을 달성하기 위하여 YMCA가 창설된 1903년부터 현재까지의 YMCA 체육활동을 살펴보았다. 1900년대 초반 체육은 우리민족에 대한 일본제국주의 식민지화를 위한 영구지배 수단의 일환으로 이용하였으며, 국내에서의 우리민족 체육활동은 일제에 대항하려는 민족정신고취와 신체단련의 목적으로 변화되었다고 할 수 있다. YMCA는 지육·덕육·체육을 통한 전인격적인 인간육성에 역점을 둔 체육활동과 스포츠의 보급으로 스포츠의 질적 향상에 큰 공헌을 하였다. 한국 역사상 서울 종로에 최초의 실내체육관을 만들어 계절이나 날씨에 상관없이 언제나 운동할 수 있도록 했고, 체육관의 부속시설로 탈의실, 친교실, 헬스장, 샤워실 등을 갖추어 체육의 장려와 위생관에도 역점을 두어 근대 체육발전의 기틀을 마련하는 역할을 담당했다. 또한 각종 경기대회를 개최하여 YMCA가 체계적으로 지도함으로 협동심, 민족자긍심, 페어플레이정신과 스포츠맨쉽 등을 심어주면서 한국 체육발전의 진흥과 전인교육에 기여하였다. YMCA는 또한 여성체육을 권장하면서 여성의 사회진출을 도왔으며, 민족고유전통경기인 씨름과 궁술대회를 통하여 우리나라 전통경기를 계승·발전시켜 왔다. 3.1운동을 기점으로 하여 YMCA 활동은 일제에 대한 실체적 대응을 위한 적극적이고 강경한 형태로 발전하게 되었다. YMCA는 점차 체육을 통한 민족정신 함양을 목적으로 체육의 민족주의적 경향을 편 체육 프로그램을 창안하고 보급하였다. 해방이후 엘리트선수 양성이 강화되자 YMCA는 시민건강교육에 바탕을 둔 사회체육보급에 주력하게 되면서 우리나라 사회체육의 발달을 가져오게 된다. 사회체육사업은 신체적성운동, 경기력향상 운동, 청소년 및 시민스포츠교실 운영, 직장인을 위한 스포츠 보급, 스포츠 동호인 클럽 조직으로 각종 스포츠를 전국적으로 확대 보급해 나갔다. YMCA는 60 - 70년대 경제성장의 양적 팽창으로 많은 성장을 하였다. 정부의 체육정책이 체육시설의 확장과 경기력 향상에 집중적인 투자를 하기 시작하면서 국력의 배양과 사회복지 등을 강조하게 되었고, 경기력 향상으로 인한 선수와 감독의 사회적 지위상승을 위한 수단으로 변해갔다. 따라서 대부분의 체육활동이 엘리트 위주로 편중되었고, 일반인들의 사회체육 참여는 상대적으로 성장하기 힘들었다. 한국은 80 - 90년대에 들어서면서 86아시안게임과 88서울올림픽을 거치면서 체육활동의 중요성이 대두되었고 우리나라 체육에도 영향을 미쳤으며, YMCA는 사회체육의 활성화를 위해 시민체육에 보다 중점을 두고 건전한 생활문화의 체육을 지향하려는 노력과 어린이에서 노인에 이르기까지 다양한 프로그램의 확대로 사회의 건전한 여가선용과 생활체육을 시민들에게 접할 수 있도록 노력하였다. This study is designed to find out what role Korean YMCA founded in the year 1903 played in unfolding national movements, promoting health and development social physical training and to explore its influence on the development of YMCA programs for physical training. With this in mind, the researcher explores YMCA physical training activities from the year 1903 up to the present. Physical culture served as part of Japanese permanent vehicles for colonizing the Koreans in the early 1900s. In this context, the domestic physical training activities were changed into serving the purpose of enhancing national fighting spirit against Japan and training the body. YMCA contributed much to the quality improvement of sports with the help of the distribution of physical-culture activities and sports focusing on cultivating one's whole personality through the culture of knowledge, wisdom and body. YMCA constructed the first in-door gymnasium in Korea, making it possible to do exercise regardless of the seasons or the weather. The gymnasium was equipped with a changing room, a friendship room, health facilities, and a shower room, etc for the purpose of promoting physical culture and controling hygiene, playing a fundamental role in developing modern physical training in Korea. YMCA contributed much to the promotion of Korean physical training and whole personality by instructing various kinds of events and by cultivating a sense of cooperation, national pride, fair play and sportsmanship, etc. YMCA helped women to advance into society by encouraging female physical culture, succeeding and developing Korean traditional sports events such as Korean wrestling and archery. Starting from the Korean Independence Movement, YMCA grew into an active and strong form with a view to coping positively with Japan. YMCA gradually created and distributed national programs for physical training with the view of cultivating national spirit with the aid of physical training. As the cultivation of elite players was consolidated after the 1985 Liberation of Korea, YMCA pushed ahead with a movement for distributing social physical culture based on the education of citizens' health, improving Korean social physical training. Social physical training enterprises kept on expanding and distributing various kinds of sports across the nation with physical-aptitude exercise, exercise for enhancing athletic performance, distribution of sports for workers and the creation of sports clubs. In the period ranging from the 1960s to the 1970s, YMCA made a lot of progress in terms of the quantitative expansion of economy. As the government began making an concentrative investment in expanding physical-training facilities and improving athletic performance, such factors as the cultivation of national power and social welfare, etc. were emphasized. In this context, physical training grew into a means for improving the social status of players and managers. Accordingly, most of the physical-training activities are conducted by the elite, and it is relatively difficult for the general public to take part in social physical training. In the period ranging from the 1980s to the 1990s, Korea hosted 86 Asian Games and 88 Seoul Olympic Games, realizing the importance of physical-training activities. YMCA has tried to promote the physical culture of healthy living culture focusing on the physical training of citizens for the cause of activation of social physical training and to provide citizens with healthy-leisure opportunities and daily physical training with the help of expanding a variety of programs for all people, young and old.

The Impact of Peer Interventions on Physical Activity for Individuals Living With Mental Illness

Wolfe, Julia C Yale University ProQuest Dissertations & Theses 2023 해외박사(DDOD)

Individuals living with mental illness have significantly reduced physical health compared to the general population, leading to a significantly decreased life expectancy. Physical activity has been shown to be an effective strategy to address many of the conditions contributing to this disparity. However, many people with mental illness do not meet the recommended levels of daily physical activity. Peer support has been shown to be effective in some aspects of recovery for individuals living with mental illness, but its effectiveness in increasing engagement with physical activity in that population is not well established. The specific aim of this report is therefore to investigate whether peer interventions increase physical activity in people living with mental illness. A literature search was performed, and results were reviewed for eligibility. The population was restricted to individuals with mental illness. Quantitative studies including peer support interventions and physical activity outcomes were eligible. Qualitative studies characterizing benefits of peer support and physical activity facilitators/barriers were also eligible. Data was extracted and charted.Twenty eligible studies were identified: eight quantitative studies investigating the effect of peer support-containing interventions on physical activity, seven qualitative studies describing the benefits of peer support in health interventions for individuals with mental illness, and five qualitative studies describing physical activity facilitators/barriers among people with mental illness.Two of the eight quantitative studies reported no significant increase in any measured aspect of physical activity. Two studies reported no significant increase in physical activity at the post-intervention time point, but significant increases appeared at 2-month or 3-month follow-up. The remaining four studies reported significant increases in physical activity measures at the post-intervention time point. The twelve reviewed qualitative studies showed that peer support in healthy lifestyle interventions provides many benefits to individuals with mental illness (support, role-modeling, hope, motivation, shared experience, practical advice, building relationships/social skills), and that those benefits align with the facilitators of physical activity (peer support, mutual support, social support, social modeling, encouragement, accountability, friends making activities innately enjoyable, group strength in facing stigma in the community, lack of power imbalance). These results suggest that peer interventions hold promise for increasing physical activity in individuals living with mental illness, based on the positive results seen in this small group of quasi-experimental and randomized control trials and the conceptual overlap seen between peer support benefits and physical activity facilitators. However, given the small number of heterogenous studies in this area to date, additional future research is needed in order to definitively answer the question and suggest the ideal form of peer support intervention to implement.

Ergonomics Studies on Obese Individuals : Joint Range of Motion and Executive Functions

정이훈 서울대학교 대학원 2021 국내박사

비만은 전 세계적으로 만연하고 있으며 미래에도 그 유행은 증가할 것으로 예상된다. 따라서 비만이 신체적 및 인지적 수행능력에 미치는 영향에 대해 연구하는 것은 필요하며, 그것은 잠재적인 산업 문제를 확인하고 해결하는 데에도 도움을 줄 수 있을 것이다. 신체적 인간공학 분야에서는 관절 가동 범위는 중요한 연구 주제이다. 왜냐하면 많은 일상 생활과 작업 활동은 신체 유연성에 영향을 받기 때문이다. 또한 많은 나라에서 노동 인구의 높은 비율이 과체중과 비만 인구이며, 이러한 비율은 미래에도 증가할 것으로 예상된다. 따라서 과체중과 비만이 신체 유연성에 미치는 영향에 대해 이해하는 것은 과체중과 비만인을 위한 다양한 제품과 시스템을 디자인하는 데에 도움을 줄 수 있으며, 산업 문제를 해결하는 데에도 도움을 줄 수 있다. 많은 일상 생활과 작업활동에서 인간은 육체적 과업 또는 자세를 유지하는 과업을 수행하면서 인지적 과업도 수행한다. 이러한 육체적/자세유지 과업과 인지적 과업은 동시에 또는 직후에 이루어진다. 그러므로 육체적/자세유지 과업과 인지적 과업과의 관계에 대해서 연구하는 것은 필요하다. 또한 육체적/자세적 부하가 있을 때 또는 가해진 직후에 비만이 인지수행능력에 미치는 영향에 대해서 연구하는 것도 필요하다. 왜냐하면 비만은 전 세계적으로 만연하고 있으며 미래에도 그 유행은 증가할 것으로 예상되기 때문이다. 위에서 언급한 중요성에도 불구하고, 비만이 신체적 및 인지적 수행능력에 미치는 영향에 대한 이해는 아직 부족하다. 비만이 관절 가동범위에 미치는 영향에 관한 과거 연구는 대부분 신체의 많은 관절들 중에서 일부분만 선택하여 연구를 실시 하였으며, 또한 과체중과 비만 인구 중에서 일부분에 집중하여 연구를 실시하였다. 육체적/자세 부하가 인지수행능력에 미치는 영향에 관한 분야에서는 육체적/자세 부하가 있을 때 또는 가해진 직후에 비만이 인지수행능력에 미치는 영향에 관한 연구는 거의 없었다. 따라서 본 연구의 목적은 비만이 관절 가동범위에 미치는 영향과 육체적/자세 부하가 있을 때 또는 가해진 직후에 비만이 인지수행능력에 미치는 영향에 관해 파악하는 것이다. 이러한 연구 목적을 달성하기 위해서 3가지 주요 연구가 수행되었다. 연구 1에서는 과체중과 비만이 관절 가동범위에 미치는 영향에 대해서 파악하였다. 관절 가동범위에 관한 공용데이터를 분석하였다. 세개의 BMI 그룹(정상체중, 과체중, 비만)이 통계적으로 비교 분석 되었다. 과체중과 비만 그룹은 정상체중 그룹에 비하여 elbow flexion, elbow supination, hip extension, hip flexion, knee flexion, ankle plantarflexion에서 통계적으로 유의미하게 작은 관절 가동범위를 보였다. 과체중과 비만 그룹은 관절 가동범위에서 knee flexion을 제외하고 통계적으로 유의미한 차이가 없었다. Knee flexion에서는 과체중과 비만 그룹 사이에서 통계적으로 유의미한 차이가 있었다. 연구 2에서는 육체적 과업을 수행한 직후에 비만이 인지수행능력에 미치는 영향에 대해서 파악하였다. 수동으로 올리기/내리기 과업이 육체적 과업으로 선정되었다. 비만 그룹은 BMI에 근거하여 두 개의 그룹(정상체중, 비만)으로 나누었다. 인지적 과업에서는 실행 기능(Executive functions)에서 핵심적인 세가지 기능(shifting, updating, inhibition)이 선정되었다. Shifting, updating, inhibition을 측정하기 위해서 숫자-글자 검사(Number-letter task), 글자 기억 검사(Letter memory task), 스트룹 검사(Stroop task)가 사용되었다. 1개의 트라이얼(Trial)은 육체적 과업과 인지적 과업의 조합을 세 번 반복하는 것으로 구성되었다. 실행 기능은 적당한 강도의 육체적 부하가 가해진 직후에 약간 향상되었고, 심한 강도의 육체적 부하가 가해진 직후에는 감소하였다. 또한 실행 기능에 관한 육체적 부하 효과에서 정상체중과 비만 그룹은 서로 다른 패턴을 보였다. 육체적 부하 강도 1에서는 비만 그룹과 정상체중 그룹의 실행 기능에는 서로 차이가 없었다. 적당한 강도의 육체적 부하가 가해진 직후에 정상체중 그룹의 실행 기능은 통계적으로 유의미하게 향상되었지만 비만 그룹에는 그러한 향상이 없었다. 연구 3에서는 자세유지 과업을 수행할 때 비만이 인지수행능력에 미치는 영향에 대해서 파악하였다. OWAS에 근거한 세 개의 자세가 자세유지 과업으로 선정되었다. 자세유지 과업을 할 때 실험참여자는 Force plate 위에서 자세를 유지하도록 하였으며, 압력 중심점(center of pressure, CoP)의 신호가 자세 동요(postural sway) 데이터를 얻기 위하여 수집되었다. 비만 그룹은 BMI에 근거하여 두 개의 그룹(정상체중, 비만)으로 나누었다. 인지적 과업에서는 실행 기능(Executive functions)에서 핵심적인 세가지 기능(shifting, updating, inhibition)이 선정되었다. Shifting, updating, inhibition을 측정하기 위해서 숫자-글자 검사(Number-letter task), 글자 기억 검사(Letter memory task), 스트룹 검사(Stroop task)가 사용되었다. 1개의 트라이얼(Trial)은 30초의 자세유지 과업과 90초 동안 자세 유지 및 인지적 과업을 동시해 수행하는 것으로 구성되었다. 실행 기능은 일반적으로 자세 부하가 있을 때 감소하는 경향을 보였다. 또한 실행 기능에 관한 자세 부하 효과에서 정상체중과 비만 그룹은 서로 다른 패턴을 보였다. 자세 부하가 강도 1에 2로 올라갈 때는 비만 그룹의 실행 기능은 통계적으로 유의미하게 감소되었지만 정상체중 그룹에는 그러한 감소가 없었다. 자세 부하가 강도 2에서 3으로 올라갈 때는 정상 그룹과 비만 그룹 모두 실행 기능이 감소하였지만, 비만 그룹이 더 두드러지게 감소하였다. 위에서 언급한 발견은 비만이 관절 가동범위에 미치는 영향에 관한 이해 뿐만 아니라 육체적/자세 부하가 있을 때 또는 가해진 직후에 비만이 인지수행능력에 미치는 영향에 관한 이해를 향상 시켰다. 연구 1에서 제공한 지식은 비만 인을 위한 작업 과업(올리기, 내리기, 물자 운반 작업) 및 제품/시스템(자동차, 워크스테이션, 가구)의 인간공학적 디자인에 유용할 것이다. 또한 연구 1에서 제공한 지식은 다양한 사이즈의 인간을 대표하는 정교한 디지털 휴먼 모델 개발에 대한 가이드라인을 제공할 수 있을 것이다. 연구 2 및 3의 발견은 일상 생활과 작업 활동에서 인간공학적 가이드라인을 제공하는데 도움을 줄 수 있을 것이다. 육체적/자세 부하와 관련된 인지수행능력의 변화는 작업 환경 및 일상 생활에서 반드시 고려되어야 한다. 특히 작업 환경에서는 안전 뿐만 아니라 작업 생산성을 위해서는 심한 강도의 육체적/자세 부하를 반드시 피해야 한다. 인지수행능력이 감소하면 작업 생산성이 감소할 수 있다. 또한 육체적/자세 부하에 있을 때 정상 체중과 비만 그룹이 실행 기능에서 서로 다른 패턴을 보이는 것도 반드시 고려되어야 한다. 특히 비만인에게는 심한 강도의 육체적/자세 부하 뿐만 아니라 적당한 강도의 육체적/자세 부하도 피하는 것이 필요하다. Obesity is prevalent worldwide and its prevalence is expected to increase in the near future. Therefore, understanding how obesity impacts physical and cognitive performance would need to be studied, and, it could help identify and address potential occupational issues through ergonomics design of work systems. In the physical ergonomics, joint range of motion (RoM) is a fundamental research topic as many daily-life and work activities are affected by body flexibility. Also, a significant proportion of the workforce in many countries are pre-obese or obese and the prevalence of these physical conditions is expected to increase in the near future. Therefore, understanding how pre-obesity and obesity impact workers’ body flexibility would benefit the design of various products and systems for pre-obese/obese users, and, help address potential occupational issues. In many daily life and work activities, people perform cognitive tasks as well as physical/postural holding tasks. The physical/postural holding tasks and cognitive tasks are conducted immediately or concurrently. Therefore, relationships between physical/postural loading and cognitive performance need to be studied. Also, obesity effects on cognitive performance immediately after or during physical/postural loading need to be examined – obesity is prevalent worldwide and its prevalence is expected to increase in the near future. Despite the importance mentioned above, understanding how obesity impacts physical and cognitive performance is still insufficient. The previous studies in relation to the obesity effects on joint range of motion examined only a limited set of joint motions and were focused on particular subsets of the pre-obese/obese population. In the physical/postural loading effects on cognitive performance, few studies examined the obesity effects on cognitive performance immediately after or during physical/postural loading. Therefore, this study aimed to investigate the obesity effects on joint RoM and obesity effects on cognitive performance immediately after or during physical/postural loading. To accomplish the objectives, three major studies were conducted. In the study 1, the pre-obesity and obesity effects on joint range of motion (RoM) for twenty-two body joint motions were investigated. A publicly available joint RoM dataset was analyzed. Three BMI groups (normal-weight, pre-obese, and obese) were statistically compared in joint RoM. The pre-obese and obese groups were found to have significantly smaller RoM means than the normal-weight for elbow flexion and supination, hip extension and flexion, knee flexion, and ankle plantarflexion. The pre-obese and obese groups exhibited no significant inter-group mean RoM differences except for knee flexion; for knee flexion, the obese group had significantly smaller RoM means than the pre-obese. In the study 2, the obesity effects on cognitive performance immediately after physical task were examined. Manual load lifting/lowering task was employed for the physical task. Obesity had two groups based on the BMI (normal-weight and obese). In the cognitive task, three core executive functions (shifting, updating, and inhibition) were employed. To measure shifting, updating, and inhibition, Number-letter task, Letter-memory task, and Stroop task were used, respectively. One trial consisted of three repeats of a combination of physical and cognitive tasks. Executive functions were slightly improved immediately after a moderate amount of physical loading; however, immediately after a severe amount of physical loading, performance of executive functions generally deteriorated. Also, different patterns of the physical loading effects on executive functions between normal-weight and obese groups were found. Obese and normal-weight groups did not differ in executive functions for physical loading level 1. Immediately after a moderate amount of physical loading, executive functions were significantly improved for the normal-weight group; however, no such significant improvement was found for the obese group. In the study 3, the obesity effects on cognitive performance during postural holding task were investigated. Three kinds of postures based on the OWAS were employed for postural holding tasks. During the postural holding task, each participant was instructed to maintain the postures on the force plate, and, the center of pressure (CoP) signals were collected to obtain postural sway data. Obesity had two groups based on the BMI (normal-weight and obese). In the cognitive task, three core executive functions (shifting, updating, and inhibition) were employed. To measure shifting, updating, and inhibition, Number-letter task, Letter-memory task, and Stroop task were used, respectively. One trial consisted 30 seconds of postural holding task and 90 seconds of concurrent postural holding and cognitive tasks. Executive functions generally deteriorated as postural loading increased. Also, different patterns of the postural loading effects on executive functions between normal-weight and obese groups were found. For the obese group, executive functions significantly deteriorated between postural loading level 1 and 2; however, no such significant deterioration was found for the normal-weight group. Between postural loading level 2 and 3, executive functions deteriorated for both the normal-weight and obese groups; however, the deterioration of executive functions was more pronounced for the obese group. The findings mentioned above improved our understanding of obesity effects on cognitive performance immediately after or during physical/postural loading as well as obesity effects on body flexibility. The knowledge provided in the study 1 would be useful for the ergonomics design of work tasks (e.g., lifting, lowering, and other materials handling tasks) and products and systems (e.g., vehicles, workstations, and furniture) for high BMI individuals. Also, the knowledge mentioned in the study 1 may guide the development of sophisticated digital human models representing differently sized individuals. The findings provided in the study 2 and 3 would be helpful to provide the ergonomics guidelines for daily life and work activities. Physical or postural loading-related changes in cognitive performance should be considered in the working environment and daily life. Especially, in the working environment, a severe amount of physical/postural loading needs to be avoided for workforce productivity as well as safety - the workforce productivity may decrease as cognitive performance deteriorates. Also, different patterns of the physical/postural loading effects on executive functions between normal-weight and obese groups should be considered in the working environment and daily life. Especially, in the working environment, for obese individuals, moderate as well as severe physical/postural loading needs to be avoided.