사족 보행 로봇의 관절고착고장을 위한내고장성 걸음새의 안정여유도에 관한 연구

양정민 대한전자공학회 2006 電子工學會論文誌-SC (System and control) Vol.43 No.5

Improvement in gait stability of fault-tolerant gaits for quadruped robots is addressed in this paper. The previously developed fault-tolerant gait gives a quadruped robot the ability to continue its walk against the occurrence of a leg failure. But it has a drawback of having marginal gait stability, which may lead to tumbling when the robot body's center of gravity is perturbed. To overcome such a drawback, a novel fault-tolerant gait is presented in this paper that generates positive stability margin against a locked joint failure, in which a joint of a leg is locked in a known place. Positive stability margin is obtained by adjusting foot positions of supporting legs between leg swing sequences. The advantages of the proposed fault-tolerant gait are discussed by comparing with the previous gait in terms of gait stability, stride length and gait velocity. 본 논문은 사족 보행 로봇에 대한 내고장성 걸음새의 안정여유도를 개선하는 방법을 논한다. 기존에 제안되었던 내고장성 걸음새는 사족 보행 로봇이 다리 고장이 발생한 후에도 보행을 계속할 수 있게 하였다. 하지만 내고장성 걸음새가 임계 안정여유도를 가지므로 몸체 무게중심의 위치가 순간적으로 바뀔 때에는 걸음새가 불안정해질 수 있다는 약점을 지니고 있다. 본 논문에서는 이러한 약점을 극복하기 위해서 양(陽)의 안정여유도를 가지는 내고장성 걸음새를 관절고착고장에 대해서 제안한다. 관절고착고장은 로봇 다리의 관절 하나가 한 지점에 고착되어 더 이상 움직일 수 없는 상태를 말한다. 양의 안정여유도는 걸음새 동작 과정에서 한 다리가 이동하기 전에 지지 다리들의 위치를 조정함으로써 얻어질 수 있다. 제안된 걸음새의 우수성을 입증하기 위해서 안정여유도, 보폭 등의 매개 변수들을 중심으로 기존 걸음새와 성능 비교를 수행한다.

다리 궤적을 조정하는 육각 보행 로봇의 내고장성 걸음새

양정민,Yang Jung-Min 대한전자공학회 2005 電子工學會論文誌-SC (System and control) Vol.42 No.3

This paper proposes a novel fault-tolerant gait planning of a hexapod robot considering kinematic constraints. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. It is shown that the conventional fault-tolerant gait of a hexapod robot for forward walking on even terrain may be fallen into deadlock, depending on the configuration of the failed leg. For coping with such deadlock situation, a novel fault-tolerant gait planning is proposed. It can avoid deadlock by adjusting the position of the foot trajectory, and has the same leg sequence and stride length as those of the conventional fault-tolerant gait. To demonstrate the superiority of the proposed scheme, a case study is presented in which a hexapod robot, having walked over even terrain before a locked joint failure, could avoid deadlock and continue its walking by the proposed fault-tolerant gait planning. 본 논문에서는 기구학적 구속조건을 고려한 육각 보행 로봇의 새로운 내고장성 걸음새를 제안한다. 본 논문에서 고려하고 있는 고장은 관절고착고장으로 로봇 다리의 관절 하나가 어떤 위치에 고착되어서 보행이 끝날 때까지 움직일 수 없는 상태를 말한다. 본 논문에서는 먼저 육각 보행 로봇의 직선 보행을 위한 기존의 내고장성 걸음새가 고장 난 다리의 기구학적 구속조건에 따라서 교착 상태에 빠질 수도 있음을 해석적으로 증명한다. 그런 다음 이러한 교착 상태를 회피하기 위해서 새로운 내고장성 걸음새 계획을 제안한다. 제안하는 내고장성 걸음새는 다리의 궤적을 변경함으로써 고장 난 다리가 야기하는 교착 상태에서 벗어날 수 있으며, 기존 내고장성 걸음새의 다리 움직임 순서와 보폭을 그대로 유지한다. 제안한 걸음새 계획의 우수성을 입증하기 위해서 평탄 지형에서 정상적인 걸음새로 걷고 있는 육각 보행 로봇이 고장이 일어난 후 제안한 걸음새 계획을 이용하여 교착 상태에서 벗어나 내고장성 걸음새로 전이하는 사례 연구도 기술한다.

The Effect of Overtreatment at Medical Institutions on the Recovery and Satisfaction of Patients

양정민,김창훈,김재현 융합연구학회 2023 융합연구학회지 Vol.7 No.1

The purpose of this study was to analyze the effect of overtreatment of inpatients at medical institutions on recovery and satisfaction. In this study, 1,098 inpatients excluding missing values were analyzed using the 6th to 10th Korea Health Panel Survey (KHPS). To identify the relationship between overtreatment and recovery and satisfaction, the chi-square test and generalized estimation equation were used for the analysis. Compared to the group that answered ‘not at all’ about overtreatment, the negative recovery degree of the group that responded ‘very much so’ was 2.995 times higher (Odds Ratio [OR]: 2.995, 95% Confidence interval: 1.338 -6.705, P-value 0.008), and dissatisfaction was 35.272 times higher (OR: 35.272, 95% CI: 14.682-84.750, P-value <0.001). Furthermore, as a result of stratified analysis of the correlation between overtreatment and recovery and satisfaction according to whether the selection treatment was recommended, the group who responded ‘very yes’ to the overtreatment or not among the group who received the selection treatment recommendation was ‘not at all’ compared to the group that responded, their negative recovery rate was 5.553 times higher and the degree of dissat- isfaction was 271.375 times higher. Whereas, in the case of the group not recom- mended for elective treatment, the negative recovery rate was 2.775 times higher and the dissatisfaction rate was 26.656 times higher. As a result of the study, the higher the group with a stronger awareness of overtreatment, the higher the degree of patient dissatisfaction and discomfort, and a particularly strong correlation was found in the group recommended for selective treatment. Hence, if the institutional standards for providing appropriate medical care to the group experiencing excessive medical treatment through medical institutions and sufficient explanations about the medical services pro- vided to patients are provided, the satisfaction and recovery of patients will increase, and it is expected to be used as the basic data for preparing policy and institutional measures towards that end.

조직확장술을 이용한 광범위한 두피 탈모의 재건

양정민,정재호,설정현 대한성형외과학회 2002 Archives of Plastic Surgery Vol.29 No.5

Tissue expansion has been used for several decades in plastic and reconstructive surgery. Recently tissue expansion of the hair bearing scalp provides an excellent surgical option for the treatment of wide alopecia.During the period 1990 to 2001, 34 patients, 37 cases of wide alopecia with various causes were treated using tissue expansion. Choice of the size, shape, and the numbers of the expander was done by a senior author. The capsule of the expanded tissue remained intact and transposition flaps were use to redistribute expanded scalp. For three patients, serial expansion was performed to completely remove the remaining alopecia. Another patients with male pattern baldness were also successfully treated using tissue expansion technique.In conclusion, tissue expansion for alopecia is a simple, safe, and reliable method and provides excellent aesthetic results. It is the treatment of choice for wide alopecia due to burn, tumor excision, traffic accident and even for male pattern baldness.

총이온화선량에 의한 고장이 존재하는 비동기 순차 회로의 교정 제어

양정민,곽성우,Yang, Jung-Min,Kwak, Seong-Woo 제어로봇시스템학회 2011 제어·로봇·시스템학회 논문지 Vol.17 No.11

This paper presents a control theoretic approach to realizing fault tolerance in asynchronous sequential circuits. The considered asynchronous circuit is assumed to work in space environment and is subject to faults caused by total ionizing dose (TID) effects. In our setting, TID effects cause permanent changes in state transition characteristics of the asynchronous circuit. Under a certain condition of reachability redundancy, it is possible to design a corrective controller so that the closed-loop system can maintain the normal behavior despite occurrences of TID faults. As a case study, the proposed control scheme is applied to an asynchronous arbiter implemented in FPGA.

Gefitinib 내성 후 Erlotinb과 한방 치료를 병행하여 호전된 뇌전이를 동반한 재발성 L858R 변이 비소세포폐암 환자 1례

양정민,장권준,황우석,Yang, Jung-min,Jang, Kwon-jun,Hwang, Woo-seok 대한한방내과학회 2022 大韓韓方內科學會誌 Vol.43 No.5

Objectives: The purpose of this study is to report the case of a patient with recurrent L858R mutation non-small-cell lung cancer with brain metastases treated with erlotinib and traditional Korean medicine after gefitinib failure. Methods: The patient was treated with erlotinib beginning in November 2021, and gamma knife surgery was performed on November 8, 2021. The dose of erlotinib was 150 mg/day every four weeks. At the same time, the patient was treated with traditional Korean medicine. Tumor size and cerebral edema were measured using computed tomography and magnetic resonance imaging, respectively. Adverse events were evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0. Results: After treatment with erlotinib and traditional Korean medicine for six months, the extent of the growing nodule in the right upper lobe decreased during the first three months and remained stable for the following three months. Peritumoral edema showed an increase three months after gamma knife surgery, but partial improvement of cerebral edema was confirmed with additional traditional Korean medicine six months after gamma knife surgery. The symptoms of discomfort and physical activity gradually improved. Conclusions: This case study suggests that the combination of EGFR-TKI and traditional Korean medicine may contribute to a reduction in tumor size and cerebral edema while improving quality of life.

비평탄 지형 보행을 위한 내고장성 FTL 걸음새

양정민 대한전자공학회 2006 電子工學會論文誌-SC (System and control) Vol.43 No.3

In this paper, fault-tolerant gait planning of a hexapod robot for walking over irregular terrain is presented. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. Based on the previously proposed fault-tolerant tripod gait for walking over even terrain, fault-tolerant follow-the-leader(FTL) gaits are proposed for a hexapod robot with a failed leg to be able to walk over two-dimensional rough terrain, maintaining static stability and fault tolerance. The proposed FTL gait can have maximum stride length for a given foot position of a failed leg, and yields better ditch crossing ability than the previously developed gaits. The applicability of the proposed FTL gait is verified by using computer graphics simulations. 본 논문에서는 비평탄 지형을 보행하기 위한 육족 보행 로봇의 내고장성 걸음새 계획을 제안한다. 본 논문에서 고려하고 있는 고장은 관절고착고장으로 로봇 다리의 관절 하나가 어떤 위치에 고착되어서 보행이 끝날 때까지 움직일 수 없는 상태를 말한다. 기존에 제안되었던 평탄 지형 보행을 위한 내고장성 세다리 걸음새 계획을 바탕으로 본 논문에서는 육족 보행 로봇이 관절고착고장이 발생한 후에도 이차원 착지 불가능 영역이 존재하는 비평탄 지형을 걸을 수 있도록 하는 내고장성 FTL(Follow-The-Leader) 걸음새를 구현한다. 제안된 FTL 걸음새는 고장 난 다리의 착지점에서 로봇이 가질 수 있는 최대한의 보폭을 낼 수 있으며, 기존 내고장성 걸음새보다 착지 불가능 영역을 뛰어넘는 능력이 더 우수하다. 컴퓨터 시뮬레이션을 통해서 제안된 FTL 걸음새의 응용가능성을 검증한다.

Association Between Objective Social Isolation and Unmet Medical Needs: A Nationwide Cross-sectional Study in Korea

양정민,Lee Seul Ki,김재현 대한예방의학회 2024 예방의학회지 Vol.57 No.3

Objectives: The aim of this study was to analyze the relationship between objective social isolation (SI) and unmet medical needs (UMN) in adults aged 19 and older.Methods: A cross-sectional analysis was conducted of 208 619 adults aged 19 and older, excluding missing data, using the 2019 Korea Community Health Survey. To analyze the association between objective SI and UMN, the chi-square test and logistic regression analysis were performed.Results: The prevalence of UMN was 1.14 times higher (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.06 to 1.23) among those with SI than among those without SI, and the OR for groups with 5 SI types was 2.77 (95% CI, 1.86 to 4.12) compared to those with no SI types. In addition, a stratified analysis by age group showed that the association between SI and UMN existed even in groups under 64 years old. However, among those aged 65 and older, SI was associated with an OR of 1.53 (95% CI, 1.37 to 1.71) for UMN compared to non-SI. As the number of SI types increased, the prevalence of UMN also increased, indicating a strong association between SI and UMN in older adults.Conclusions: This study found that individuals with SI experienced UMN due to fear and anxiety about interpersonal relationships. Therefore, based on the results of this cross-sectional study, it is necessary to investigate the causal relationship between SI and UMN through future longitudinal data.

독거가구 및 기초생활수급 여부와 절주권고, 음주문제 상담 간의 연관성 분석

양정민,김하은,김재현 한국병원경영학회 2022 병원경영학회지 Vol.27 No.4

Purpose: The purpose of this study was to analyze the association between single-person households & Beneficiary of National Basic Livelihood and recommendation on alcohol consumption, and counseling on drinking problems for adults 19 years of age or older. Methods: In this study, excluding missing values, the association between the single-person household & Beneficiary of National Basic Livelihood and recommendation to refrain drinking alcohol, counseling for drinking problems was analyzed by using the chi-squre test and logistic regression analysis. Results: In the case of non-single person households, compared to single-person households, the recommendation rate to refrain drinking alcohol was 1.519 OR (Odds Ratio [OR]: 1.159 , p-value <.0001). meanwhile, in the case of Beneficiary of National Basic Livelihood, the recommendation rate to refrain alcohol consumption was higher by 1.414 OR (OR: 1.414, p-value: 0.011), and the drinking problem counseling rate was also higher by 2.257 OR (OR: 2.257, p-value: 0.026) compared to non-beneficiary group. Discussion & Conclusion: Based on the 2016-2019 National Health and Nutrition Survey, this study investigated the associaiton between single households & Beneficiary of National Basic Livelihood and recommendations to refrain alcohol, and counseling on drinking problems. Compared to the Beneficiary of National Basic Livelihood group, single-person household group has recently been classified as a socially vulnerable group, but it is not applicable in the policy category. If policy and institutional measures for treatment are provided, it is expected that the problem of alcohol abuse can be reduced.

인공지능 컴퓨팅 프로세서 반도체 동향과 ETRI의 자율주행 인공지능 프로세서

양정민,권영수,강성원,Yang, J.M.,Kwon, Y.S.,Kang, S.W. 한국전자통신연구원 2017 전자통신동향분석 Vol.32 No.6

Neural network based AI computing is a promising technology that reflects the recognition and decision operation of human beings. Early AI computing processors were composed of GPUs and CPUs; however, the dramatic increment of a floating point operation requires an energy efficient AI processor with a highly parallelized architecture. In this paper, we analyze the trends in processor architectures for AI computing. Some architectures are still composed using GPUs. However, they reduce the size of each processing unit by allowing a half precision operation, and raise the processing unit density. Other architectures concentrate on matrix multiplication, and require the construction of dedicated hardware for a fast vector operation. Finally, we propose our own inAB processor architecture and introduce domestic cutting-edge processor design capabilities.