IEEE 802.15.4기반 센서 네트워크에서 슬립거부 공격의 취약성 분석 및 탐지 메커니즘

김아름,김미희,채기준,Kim, A-Reum,Kim, Mi-Hui,Chae, Ki-Joon 한국정보처리학회 2010 정보처리학회논문지 C : 정보통신,정보보안 Vol.17 No.1

IEEE 802.15.4[1] has been standardized for the physical layer and MAC layer of LR-PANs(Low Rate-Wireless Personal Area Networks) as a technology for operations with low power on sensor networks. The standardization is applied to the variety of applications in the shortrange wireless communication with limited output and performance, for example wireless sensor or virtual wire, but it includes vulnerabilities for various attacks because of the lack of security researches. In this paper, we analyze the vulnerabilities against the denial of sleep attacks on the MAC layer of IEEE 802.15.4, and propose a detection mechanism against it. In results, we analyzed the possibilities of denial of sleep attacks by the modification of superframe, the modification of CW(Contention Window), the process of channel scan or PAN association, and so on. Moreover, we comprehended that some of these attacks can mount even though the standardized security services such as encryption or authentication are performed. In addition to, we model for denial of sleep attacks by Beacon/Association Request messages, and propose a detection mechanism against them. This detection mechanism utilizes the management table consisting of the interval and node ID of request messages, and signal strength. In simulation results, we can show the effect of attacks, the detection possibility and performance superiorities of proposed mechanism. IEEE 802.15.4 표준기술[1]은 센서 네트워크에서 저전력을 위한 기술로 LR-WPANs(Low Rate-Wireless Personal Area Networks)의 물리 계층과 MAC계층을 규정한다. 이 표준은 무선 센서, 가상 선(Virtual Wire)과 같은 제한된 출력과 성능으로 간단한 단거리 무선 통신을 필요로 하는 폭넓은 응용에 활용되고 있지만 보안 측면의 연구는 현재 미비한 상태로 다양한 공격에 대한 취약점을 내포하고 있다. 본 논문에서는 802.15.4 MAC계층의 슬립거부(Denial of Sleep) 공격에 대한 취약성을 분석하고 이를 탐지하는 메커니즘을 제안한다. 분석 결과, 슈퍼프레임 구간 변경, CW(Contention Window)값 변경, 채널스캔 및 PAN 연합과정 등에서 슬립거부 공격의 가능성을 분석할 수 있었고, 이 과정 중 일부에서는 표준에서 정의한 인증과 암호화 기능이 적용되어도 공격 가능함을 알 수 있었다. 또한 본 논문에서는 분석된 취약점 중에 채널스캔 및 PAN 연합과정에서 Beacon/Association Request 메시지 위조를 통한 슬립거부 공격의 탐지 메커니즘을 제안한다. 제안된 메커니즘은 메시지 요청 간격, 요청 노드 ID, 신호 세기 등을 모니터링하여 공격을 식별하여 탐지한다. QualNet 시뮬레이션 툴을 사용하여 공격의 영향 및 제안된 탐지 메커니즘의 탐지 가능성과 성능의 우수성을 입증할 수 있었다.

복원된 양재천에서 복원 효과 평가 및 평가 결과에 기초한 개선방안

김아름,김동욱,임봉순,설재원,이창석,Kim, A Reum,Kim, Dong Uk,Lim, Bong Soon,Seol, Jae Won,Lee, Chang Seok 한국하천호수학회 2020 생태와 환경 Vol.53 No.4

This study was carried out to evaluate the restoration effect in the restored Yangjae stream and to draw up an adaptive management plan based on the results. As the result of evaluation on the restoration effect, the restored Yangjae stream was evaluated with low naturalness in both terms of the morphology of the stream and the composition and spatial distribution of vegetation. The diverse functional groups were introduced in the vegetation restoration, but the flooding regime, which is significant in the spatial distribution of riparian vegetation, were not correctly reflected. Exotic species or species that were not ecologically suitable for the location were introduced on the embankment and thus a measure to improve those problems is required. As the ecological principle was not reflected in the restoration plan, the stream was constructed as the double terrace structure. Therefore, the width of the waterway was narrowed further, and the waterfront was not designed to accommodate changes from flooding disturbance, making the micro-topography of the stream simpler and the naturalness lower. The adaptive management plan was prepared to improve those problems, and a plan for creating an ecological network was recommended to enhance the restoration effect.

A Study on the Condition Diagnosis for A Gas-insulated Transformer using Decomposition Gas Analysis

김아름,곽병섭,전태현,박현주,Ah-Reum, Kim,Byeong Sub, Kwak,Tae-Hyun, Jun,Hyun-joo, Park Korea Electric Power Corporation 2022 KEPCO Journal on electric power and energy Vol.8 No.2

A growing number of gas-insulated transformers in underground power substations in urban areas are approaching 20 years of operation, the time when failures begin to occur. It is thus essential to prevent failure through accurate condition diagnosis of the given facility. Various solid insulation materials exist inside of the transformers, and the generated decomposition gas may differ for each gas-insulated equipment. In this study, a simulation system was designed to analyze the deterioration characteristics of SF₆ decomposition gas and insulation materials under the conditions of partial discharge and thermal fault for diagnosis of gas-insulated transformers. Degradation characteristics of the insulation materials was determined using an automatic viscometer and FT-IR. The analysis results showed that the pattern of decomposition gas generation under partial discharge and thermal fault was different. In particular, acetaldehyde was detected under a thermal fault in all types of insulation, but not under partial discharge or an arc condition. In addition, in the case of insulation materials, deterioration of the insulation itself rapidly progressed as the experimental temperature increased. It was confirmed that it was possible to diagnose the internal discharge or thermal fault occurrence of the transformer through the ratio and type of decomposition gas generated in the gas-insulated transformer.

PVA 중합도가 고상-액상 혼합 방식에 의한 YAG:Ce³⁺ 형광체 분말 합성에 미치는 영향

김아름,이상진,Kim, A-Reum,Lee, Sang-Jin 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.5

YAG:$Ce^{3+}$ phosphor powders were synthesized using $Al(OH)_3$ seeds by means of a PVA-polymer-solution route. Various types of PVA with different molecular weights (different polymerization) were used. All dried precursor gels were calcined at $500^{\circ}C$ and then heated at $1500^{\circ}C$ in a mix of nitrogen and hydrogen gases. The final powders were characterized via XRD, SEM, PSA, PL, and PKG analyses. The phosphor properties and morphologies of the synthesized powders were dependent on the PVA type. As the molecular weight of the PVA was increased, the particle size gradually decreased with agglomeration, and the luminous intensity of the phosphor increased. However, the phosphor powder prepared from the PVA exhibiting very high molecular weight, showed a 531 nm (blue) shift from the 541 nm (yellow) wavelength of the YAG:$Ce^{3+}$ phosphor. Finally, the synthesized YAG:$Ce^{3+}$ phosphor powder prepared from the PVA with 89,000 - 98,000 molecular weight showed phosphor properties similar to those of a commercial phosphor powder, but without a post-treatment process.

자연정화공법을 이용한 소형 축산폐수처리장치의 최적여재 선정

김아름(Ah-Reum Kim),김홍출(Hong-Chul Kim),서동철(Dong-Cheol Seo),박종환(Jong-Hwan Park),김성헌(Sung-Hun Kim),이성태(Seong-Tae Lee),정태욱(Tae-Uk Jeong),최정호(Jeong-Ho Choi),김현욱(Hyunook Kim),조주식(Ju-Sik Cho),허종수(Jong-Soo Heo) 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.2

소규모 축산농가로부터 발생되는 축산폐수를 효과적으로 처리하기 위한 인공습지를 개발하기 위하여 인공습지에서 가장 중요한 인자 중 하나인 최적 여재의 선정에 관하여 연구하였다. 최적여재를 선정하기 위하여 여재를 왕사, 쇄석, 제올라이트 및 방해석으로 달리하여 충진한 후 각 여재별 축산폐수 처리효율 조사한 결과 COD 처리효율은 왕사가 다른 여재에 비하여 높았고, SS 처리효율은 모든 여재에서 94~95%로 큰 차이 없었다. 또한 T-N 처리효율은 제올라이트가 다른여재에 비해 높았고, T-P 처리효율은 방해석이 다른여재에 비해 높았다. 이상의 결과에서 COD,SS, T-N 및 T-P 모두를 안정적으로 처리할 수 있는 최적여재는 왕사였다. 소형 축산폐수처리장치에서 질소와 인 처리효율을 극대화 하기 위해 호기성조 (왕사:쇄석:방해석=3:2:1)와 혐기성조 (왕사:쇄석:제올라이트=3:2:1)에 혼합여재를 주입한 결과 최적 여재인 왕사에 비해 질소 및 인 처리효율이 각각 15% 및 7% 향상되었다. In order to develop livestock wastewater treatment technology by natural purification method, the optimum filter media in small-scale livestock wastewater treatment apparatus for treating livestock wastewater were studied. Removal rates of pollutants under different filter media were in the other of coarse sand ≒ broken stone > zeolite > calcite for COD, zeolite >> broken stone ≒ coarse sand ≒ calcite for T-N, and calcite > coarse sand ≒ broken stone ≒ zeolite for T-P. Based on the above results, the optimum filter media was coarse sand in small-scale livestock wastewater treatment apparatus. To meet acceptable effluent quality standard for livestock wastewater and to improve T-N and T-P removal efficiencies, removal efficiencies of pollutants in small-scale livestock wastewater treatment apparatus with mixed filter media were studied. The removal rates of COD, SS, T-N and T-P in effluent were 84, 94, 65 and 98% in small-scale livestock wastewater treatment apparatus with mixed filter media, respectively. For increasing the T-N and T-P removals in small-scale livestock wastewater treatment apparatus, the mixed filter media are recommended.

프랜차이즈 헤어살롱 인턴의 교육에 대한 만족, 활용, 직업몰입에 관한 연구

김아름 ( Ah Reum Kim ),박은준 ( Eun Jun Park ) 한국미용학회 2018 한국미용학회지 Vol.24 No.2

The purpose of this study is to examine the relationship among the satisfaction of the education, educational application, and occupational commitment of all interns at franchise hair salons. In addition it focuses on analyzing factors that increase occupational commitment to contribute the most important educational programs in human resources management with strong guidance. As for the subject of this study, a total of 270 questionnaires were distributed, and 250 of them were retrieved and statistical data was obtained with 244 valid questionnaires. SPSS 22.0 was used to analyze the collected data. Analytical analysis was carried out on the data in the form of frequency analysis, factor analysis, reliability analysis, and regression analysis. First of all, interns’ satisfaction of the education influenced the relationship commitments in the order of the satisfaction of the education system and the gratification of the education effect. Secondly, educational application has a significant effect on relationship commitment in the order of practical, psychological, and theoretical aspects, and on occupational commitment in order of psychological, theoretical, and practical aspects. In conclusion, on the basis of this research, it can be seen that companies should develop their employees’ abilities to provide psychological stability, a sense of belonging, and systematize level-specific education according to their ability to work. In addition, to provide high quality service to customers, they should investigate the satisfaction of employees' education and improve the quality of education. Furthermore, they should elevate employees’ minds so that they have confidence in their jobs, responsibility for their duties and solid work ethic.

충북지역 노인복지시설 회합급식프로그램에 대한 이용노인 대상 급식품질 만족도

김아름(A Reum Kim),이영은(Young Eun Lee) 충북대학교 생활과학연구소 2011 생활과학연구논총 Vol.15 No.1

The purpose of this study were to examine perceptions and to analyze satisfaction of welfare facilities for the aged in order to suggest some ways to increase the congregate meal program quality and promote its efficient operation. A questionnaire survey was conducted to total 407 subjects. The survey period was March 10 to 14, 2008. The collected data were statistically treated with SAS package program. The results of this study were follows: Most use the congregate meal program 5 times per week but want to use 7 times per week. The quality attributes of meal program were rearranged into three factors in terms of service, sanitation and food. The overall satisfaction score was 4.2 points out of 5 point. The satisfaction score of the facilities operated by public institutions and religious organizations was higher than by nongovernmental organizations. According to multiple regression analysis, 80.99% of the variance in respondent’s satisfaction score could be explained by quality attribute of the meal program. The menu variety and the number of side dish and the convenience of facilities was the important factors influenced on overall satisfaction.

전문가와 비전문가의 모발건조 행위가 손상도 인식, 관심도, 만족도에 미치는 영향

김아름(Kim, A Reum),조지훈(Cho, Ji Hoon) 한국디자인문화학회 2018 한국디자인문화학회지 Vol.24 No.1

본 연구는 전문가와 비전문가의 모발건조 행위에 따른 손상도 인식, 모발건조 관심도, 만족도에 관한 영향을 분석하여 모발건조 행위에 대한 미용전문가의 기초자료와 활용방안을 도출하고자 연구하였다. 연구의 분석은 SPSS WIN 21.O을 사용하여 빈도분석, 탐색적 요인분석, 다중회귀분석을 실시하였다. 본 연구의 결과는 다음과 같다. 첫째, 전문가는 모발건조 행위의 선택적 요인이 높을수록, 비전문가는 모발건조행위의 조건적 요인이 높을수록 손상도 인식(β=.356, p<.01, β=.331, p<.001), (β=.252, p<.01, β=.161, p<.05), 모발건조 관심도(β=.213, p<.01, β=.285, p<.001), 만족도(β=.167, p<.01, β=.206, p<.01), (β=.219, p<.01, β=.167, p<.05)에 영향을 미치는 것으로 나타났다. 둘째, 간접적 손상인식이 높을수록 전문가와 비전문가 모두에서 감각적 만족도(β=.275, p<.01, β=.173, p<.05) 가 높은 것으로 나타났고, 직접적 손상인식이 높을수록 지각적 만족도(β=.174, p<.05)도 높아지는 것은 전문가에게서만 나타났다. 셋째, 모발건조 행위에 대한 모발건조 관심도가 높으면 전문가와 비전문가 모두에서 감각적 만족도(β=.346, p<.001, β=.267, p<.001)와 지각적 만족도(β=.504, p<.001, β=.466, p<.001)도 높은 결과가 나타났다. 이러한 결과는 모발건조 행위가 전문가의 관점에서는 선택적, 지각적으로 판단되고 비전문가의 관점에서는 조건적, 감각적으로 판단되고 있음을 시사한다. 그러므로 전문가는 고객인 비전문가의 보편적이고 일반적인 사고를 인식하여 모발건조 행위를 제공하기를 제안한다. 이는 미용전문가가 비전문가의 신뢰와 만족을 획득할 수 있게 하는 긍정적 효과가 유발되는 것에 의의를 갖는다. 그러나 특정하지는 않았지만 지역적 한계가 있고, 대상자가 부족함으로 표준화하기에는 미흡하다할 수 있다. 따라서 향후 보완적인 연구가 이뤄지기를 기대한다. The purpose of this study was to investigate the effects of hair dryness behavior between specialist and non-specialist on the degree of damage awareness, interest, and satisfaction. Through this study, this paper has studied this to derive the basic data and application plan of beauty specialists on hair drying behavior. SPSS WIN 21.O was used for the analysis of the study. Frequency analysis, exploratory factor analysis, and multiple regression analysis were performed. The results of this study are as follows. First, to the specialist, the degree of damage awareness (β=.356, p<.01, β=.331, p<.001), interest (β=.213, p<.01, β=.285, p<.001), and satisfaction (β=.167, p<.01, β=.206, p<.01), (β=.219, p<.01, β=.167, p<.05) were affect to the higher the selective factor of hair dryness. And to the non-specialist, affect to the higher the conditional factors of the hair drying act. Second, to the both specialist and non-specialist, the higher the indirect damage awareness, the higher the sensory satisfaction (β=.275, p<.01, β=.173, p<.05), and it was shown only to specialist the higher the direct damage awareness, the higher the perceptual satisfaction (β=.174, p<.05). Third, the higher the degree of interest in the hair drying behavior, the higher the sensory satisfaction (β =.346, p<.001, β=.267, p<.001) and the perceived satisfaction (β=.504, p<.001, β=.466, p<.001) were also high to the specialist and non-specialist both. These results suggest that hair drying behavior is judged selectively and perceived from the viewpoint of specialists and from the viewpoint of non-specialists, it is judged conditional and sensory. Therefore, this paper suggests that the specialist need to recognizes the universal and general thought of non-specialist who is the client, and provide hair-drying behavior. This implies that a positive effect is created which enables the beauty specialist to obtain the trust and satisfaction of the non-specialist. However, it is not specific, but there are regional limitations, and there is insufficient standardization due to lack of target person. Therefore, it is expected that complementary study will be done in the future.

헤어살롱의 관계마케팅이 살롱선택속성과 고객만족에 미치는 영향

김아름 ( Ah Reum Kim ),전근옥 ( Gun Ok Jun ),조현진 ( Hyeon Jin Jo ),박은준 ( Eun Jun Park ) 한국미용학회 2020 한국미용학회지 Vol.26 No.5

The recent diversification of consumer tastes has caused supply to exceed demand, shifting the market's lead from businesses to heads. In this competitive market environment, hair salons are experiencing major difficulties in management, and attracting customers among them is a major problem. In this study, the effect of relationship marketing on saloon selection and satisfaction is found among customers using salons and the design of programs to attract customers is significant. The questionnaire was used in the study and the collected data was analyzed using SPS 22.0. To determine the effect between each parameter, the effect of the parameter was determined using regression and parametric regression. The results showed that unmarried women in their 20s had the highest response rate, the average monthly Sodden was between 2 and 3 million, the grade was college students, and the profession was the highest. Relationship marketing was derived from operation services and communication, and customer satisfaction was derived with brand attributes, internal attributes and external attributes, with the degree of satisfaction, recommendation and revisit. Each parameter was shown to affect each other. It is expected that the number of new customers will increase through the recommendation of fixed customers by making efforts to communicate with customers and establishing a revisit system and membership system in Salon.

조기 경보를 위한 화재 판단 알고리즘을 이용한 무선 센서네트워크 기반 화재 감시 응용 시스템 설계 및 구현

김아름(Ah-Reum Kim),조경진(Kyoung-Jin Jo),장재우(Jae-Woo Chang),심춘보(Chun-Bo Sim) 한국콘텐츠학회 2009 한국콘텐츠학회논문지 Vol.9 No.12

최근 문화재나 시설물 관리를 위한 화재 감시 응용 시스템에 대한 요구가 증대되고 있다. 이러한 화재 감시 시스템은 화재 상황을 대처할 수 있도록 지원함으로써 피해규모를 축소시킬 수 있다. 그러나 기존 시스템은 일정 주기로 화재 감시를 수행함으로써 화재 판단을 지연시키는 단점이 존재한다. 또한 감시 상황을 확인 할 수 있는 사용자 인터페이스를 제공하지 않는다. 따라서 이러한 두 가지 문제점을 해결하기 위하여 첫째, 조기 위험상황 경보를 위해 새로운 화재 판단 알고리즘(Early Fire Detection Algorithm)을 제안한다. 이는 데이터 분포를 기반으로 하여 화재 판단 시작 주기를 동적으로 설정하기 때문에, 화재 판단 시간 측면에서 기존 알고리즘 보다 우수하다. 둘째, 제안하는 화재 판단 알고리즘을 통하여 사용자 인터페이스를 제공하는 화재 감시 응용 시스템을 개발한다. 마지막으로 성능 실험을 통해, 개발된 시스템이 다양한 화재 상황에서 조기 위험상황 경보를 위해 활용될 수 있음을 보인다. Recently, fire monitoring application systems have been an active research area due to the safety of industries, historical monuments and so on. The fire monitoring application systems can reduce the damage of properties by providing earlier warning for possible fire situation. However, the existing systems have a drawback that they detect fire with delay due to their uniform epoch in fire detection algorithm. Moreover, they do not provide user-friendly graphical user interfaces in their fire monitoring systems. To resolve the problems, First, we propose a new fire detection algorithm (Early Fire Detection Fire Algorithm) which uses the distribution of sensing data for early fire detection. Our fire detection algorithm is better in terms of fire detection time than the existing work because it can set a start time of fire detection epoch dynamically based on data distribution. Second, we develop a fire monitoring application system which provides users with both a user-friendly graphical user interface and a fire alarm message when fire occurs. Finally, we show from our experiment that our developed system is effectively used for early fire warning in a variety of fire situations.