광원의 특성에 따른 Boron-doped p-type Cz-Si 태양전지의 광열화 현상 분석

김수민,배수현,김영도,박성은,강윤묵,이해석,김동환,Kim, Soo Min,Bae, Soohyun,Kim, Young Do,Park, Sungeun,Kang, Yoonmook,Lee, Haeseok,Kim, Donghwan 한국재료학회 2014 한국재료학회지 Vol.24 No.6

When sunlight irradiates a boron-doped p-type solar cell, the formation of BsO2i decreases the power-conversion efficiency in a phenomenon named light-induced degradation (LID). In this study, we used boron-doped p-type Cz-Si solar cells to monitor this degradation process in relation to irradiation wavelength, intensity and duration of the light source, and investigated the reliability of the LID effects, as well. When halogen light irradiated a substrate, the LID rate increased more rapidly than for irradiation with xenon light. For different intensities of halogen light (e.g., 1 SUN and 0.1 SUN), a lower-limit value of LID showed a similar trend in each case; however, the rate reached at the intensity of 0.1 SUN was three times slower than that at 1 SUN. Open-circuit voltage increased with increasing duration of irradiation because the defect-formation rate of LID was slow. Therefore, we suppose that sufficient time is needed to increase LID defects. After a recovery process to restore the initial value, the lower-limit open-circuit voltage exhibited during the re-degradation process showed a trend similar to that in the first degradation process. We suggest that the proportion of the LID in boron-doped p-type Cz-Si solar cells has high correlation with the normalized defect concentrations (NDC) of BsO2i. This can be calculated using the extracted minority-carrier diffusion-length with internal quantum efficiency (IQE) analysis.

술후 감염조절이 어려웠던 환자의 증례보고

김수민,여환호,김영균,김수관,서재훈,박인순,박인수,김용욱,Kim, Soo-Min,Yeo, Hwan-Ho,Kim, Young-Kyun,Kim, Su-Gwan,Seo, Jae-Hoon,Park, In-Soon,Park, In-Soo,Kim, Young-Uk 대한악안면성형재건외과학회 1997 Maxillofacial Plastic Reconstructive Surgery Vol.19 No.1

Treatment of infected mandibular fracture is confronted with various difficult problem, e.g. nosocomial wound infection, non-union of fracture, osteomyelitis. Recently, nosocomial infection has become a major health problem because of excessive morbidity, personal distress, and cost. Frequently, isolated causative microorganisms of nosocomial infection were staphylococcus aureus, pseudomonas aeruginosa, klebsiella species. The various manifestation of the disease related to the pathogenesis and the clinical course tend to give a bad prognosis after operation. This is a report of case that post-operative infected mandibular fracture in 53-year-old man was not healed even through aggressive I & D and antibiotic treatment.

2단 실린더형 싸이클론의 물 및 오일 액적 제거 성능 분석 연구

김수민,김학준,김명준,한방우,우창규,김용진,Kim, Sumin,Kim, Hak-Joon,Kim, Myungjoon,Han, Bangwoo,Woo, Chang Gyu,Kim, Yong-Jin 한국입자에어로졸학회 2017 Particle and Aerosol Research Vol.13 No.3

A novel two stage cylindrical cyclone was developed for a 3 phase separator in shale oil production industry. The cyclone performance was compared with a cone type cyclone and multi cyclone at the same experimental condition using water and oil mists generated by a humidifier and atomizer at the flow rate 1 to $2m^3/min$. The removal efficiency of total suspended water droplets by the novel cyclone, calculated using inlet and outlet concentrations measured by an optical particle counter, was 99% which is higher than 90% of oil droplet removal efficiency at $2m^3/min$. It might be due to the evaporation of small water droplets during the tests. The water and oil droplet removal performance of the novel cyclone based on the quality factor which is a function of pressure drop and removal efficiency was the highest among three cyclones. The results indicate that the cyclone could be an economical device to remove water and oil mists from shale gas generation processes where a huge three phase separator is commonly used.

멜라민 화합물을 이용한 산화 그래핀 도핑 및 특성 평가

김수민,김현,김소양,한종훈,Kim, Sumin,Kim, Hyun,Kim, So Yang,Han, Jong Hun 한국재료학회 2019 한국재료학회지 Vol.29 No.11

In this paper, nitrogen-doped reduced graphene oxide(rGO) is obtained by thermal annealing of nitrogen-containing compounds and graphene oxide (GO) manufactured by modified Hummers' method. We use melamine as a nitrogen-containing compound and treat GO thermally with melamine at over $800{\sim}1,000^{\circ}C$ and 1 ~ 3 hr under Ar atmosphere. The electrical conductivity of doped rGO is measured by 4-point probe method. As a result, nitrogen contents on rGO are found to be in the range of 2.5 to 12.5 at% depending on the doping conditions after thermal annealing. The main doping site on graphene oxide is changed from pyridinic-N and pyrrolinic N to the graphitic site as the heat treatment temperature increases. The electrical conductivity of doped rGO increases as the N doping content increases. As the thermal treatment time increases, the change of both total doping contents and doping sites is slight and the surface resistance is remarkably reduced, which is caused by healing effects of doped graphene oxide at high temperature.

편마비 환자의 견관절 아탈구 측정법과 치료

김수민,권미지,Kim, Soo-Min,Kwon, Mi-Ji 대한물리치료과학회 1994 대한물리치료과학회지 Vol.1 No.2

Shoulder pain is probably the most frequent complication of hemiplegia. Many of the factors contributing to the occurrence of shoulder pain in hemiplegia have shown that the lesions of the rotator cuff tendon or the tendon of the long head of the biceps brachii, the reflex sympathetic dystrophy syndrome, shoulder-hand syndrome, subluxation and rupture of the rotator cuff. Subluxation has been measured by finger breadths, X-Ray, Radiological measure and jig device. The propose of this study decribes the sourse of shoulder pain with hemiplegia, method for subluxation measure and treatment of. hemiplegic shoulder pain.

Vitamin C 와 Vitamin E 처리가 한우육의 육색 및 지방산화에 미치는 영향

김수민,이신호,성삼경 ( S . M . Kim,S . H . Lee,S . K . Sung ) 한국축산학회 1997 한국축산학회지 Vol.39 No.3

The effects of vitamin C concentration and vitamin E on lipid peroxidation and meat color were determined by spraying the vitamins on meat, Binding them together, and storing at 5℃ either in a dark room or a fluorescent lighted room. The meat in the dark room showed low TBARS value. Vitamin C was effective to retard the pigment and lipid oxidation, irrespective of storage conditions. However, there were not significant differences between 1% vitamin C and 3% vitamin C groups. The treatment of vitamin C and vitamin E played a role as the most powerful antioxidants to reduce lipid oxidation. The concentration of vitamin C tended to be decreased gadually with times and 3% vitamin C had the highest degradation rate. The effects of vitamin C concentration on meat color and meat flavour were determined at the difTerent storage conditions. The lightness of meat color treated with I% vitamin C and 3% vitamin C fumed out to be very high at dark room until 5 days. The redness of meat color had very similar tendency to the lightness of meat color at dark room until 5 days. After 5 days of storage, there were not significant differences. The result of the sensory test indicated that the change of meat color tended to be decreased gradually, but there were not significant differences during storage at 5℃. However, vitamin C treatment had a slightly higher score in meat color than that of control after storage for 5 days, irrespective of storage conditions(P$lt;0.05). Meat with 3% vitamin C was the most effective to keep meat color during the storage for 10 days. And also, meat flavour tended to be decreased during storage at 5℃, but there were not distinct differences according to vitamin C concentration.

분산 안테나 시스템에 기반한 무선 액세스망 가상화

김수민,정방철,Kim, Su Min,Jung, Bang Chul 한국정보통신학회 2012 한국정보통신학회논문지 Vol.16 No.10

본 논문에서는 다수 무선 접속 기술 (Radio Access Technology; RAT)이 통합되어 운용되는 셀룰러 네트워크에서 차세대 이동통신 네트워크 진화 방향인 디지털 유닛 (DU)-라디오 유닛 (RU) 분리 구조를 기본으로 무선 액세스 네트워크 가상화 알고리즘을 제안한다. 제안 무선 액세스 네트워크 가상화 알고리즘은 크게 기본 액세스 네트워크 가상화, RAT 가상화, 액세스 경로 이주 알고리즘으로 구성되고, 순차적인 수행을 통하여 최종 무선 액세스 네트워크 가상화가 이루어진다. 제안 무선 액세스 네트워크 가상화 알고리즘은 3GPP LTE와 WiMAX의 두 무선 접속 기술을 예제로 한 시스템 레벨 시뮬레이션을 통하여 시스템 수율 측면에서 성능이 평가된다. 이 때, 네트워크 트래픽 로드의 비대칭성에 따른 두 가지 시나리오를 고려하고, 제안 무선 액세스 네트워크 가상화 알고리즘은 비대칭적 네트워크 트래픽 로드와 사용자 분포 상황에서도 상당한 성능 이득을 성취한다. In this paper, we propose a wireless access network virtualization algorithm based on a digital unit (DU)-radio unit (RU) separated network structure in a cellular network with multiple radio access technologies (RATs). The proposed wireless access network virtualization algorithm consists of a baseline access network virtualization, RAT virtualization, and access path migration algorithms. Final wireless access network virtualization is performed by sequentially performing these procedures. Through system-level simulations which assume 3GPP LTE and WiMAX systems, the performance of the proposed wireless access network virtualization is evaluated in terms of system throughput for two scenarios according to asymmetry of network traffic load. Numerical results show that our proposed wireless access network virtualization algorithm achieves significant system throughput gain even in asymmetric traffic load and user distribution situations.

지역사회 고령자의 낙상경험에 따른 위험요인 비교

김수민,Kim, Soo-Min 대한고유수용성신경근촉진법학회 2016 PNF and Movement Vol.14 No.2

Purpose: This study aimed to investigate the factors that increase fall risk in the residential environment and the perceived fall risk among community-dwelling elderly through comparisons between fallers and non-fallers. Methods: The subjects were 95 community-dwelling elderly aged 65 years and over residing in the metropolitan city of Ulsan. A structured questionnaire consisting of items on sociodemographics and health- and fall-related characteristics was used and data were collected from July to August 2015. The data were analyzed with the SPSS/WIN program. Results: Among recent fallers, 38.9% had diagnosed diseases when the fall occurred, 56.87% were fearful of a recurrent fall, and 86.5% stated that they were increasing their carefulness but that had led to a decrease in activity. There were significant differences between elders who had fallen at least once and elders who had no falls in age, health status, depression, the experience of falling, fear of falling, diseases, and medications. Conclusion: The results indicate a need to assess risk factors to identify older adults with a high risk for falling and the need to develop multifactorial intervention programs that consider both environmental and perceived risk factors as well as physical risk factors to reduce and prevent falls among the elderly.

고기 혼합물에서 철 관련 지방산화에 미치는 Ascorbic acid 와 산소종의 영향

김수민,조영석,이신호,김대곤,성삼경 ( S . M . Kim,Y . S . Cho,S . H . Lee,D . G . Kim,S . K . Sung ) 한국축산학회 1998 한국축산학회지 Vol.40 No.1

The effects of prooxidants on lipid oxidation were determined in meat homogenate. Sample were prepared by adding free iron and heme pigment into meat homogenate. Ferrous(Fe^(2+)) and Ferric(Fe^(3+)) ions were very strong catalyst to generate lipid oxidation. Ferric(Fe^(3+)) ion had same 2-thiobarbituric acid reactive substances (TBARS) value as Ferrous(Fe^(2+)) ion in meat homogenate. As the amounts of total iron in hemoglobin (Hb) were very low, it was acted as very weak catalyst of lipid oxidation in meat homogenate in control. The effect of iron sources reacted with H₂O₂ and H₂O₂ + Fe^(2+) on lipid oxidation were not different in TBARS value, even though H₂O₂ + Fe^(2+) has more total iron than that of H₂O₂. On the other hand, iron sources reacted with KO₂ were very similar to those of xanthine oxidase (XOD) in TBARS value. Especially, although Hb reacted with KO₂ was lower than that of Hb reacted with XOD in amounts of total iron, Hb reacted with KO₂ and XOD had same TBARS value as a weak catalyst to generate lipid oxidation. It was concluded that the iron sources important in the catalyst of lipid oxidation were Fe^(2+) and Fe^(3+) ions in the meat homogenate. However Hb was a very weak catalyst of lipid oxidation in meat homogenate.

환자의 활력 징후를 이용한 후향적 데이터의 분석과 연구를 위한 데이터 가공 및 시각화 방법

김수민,윤지영,Kim, Su Min,Yoon, Ji Young 대한의용생체공학회 2021 의공학회지 Vol.42 No.4

Purpose: Vital sign are used to help assess the general physical health of a person, give clues to possible diseases, and show progress toward recovery. Researchers are using vital sign data and AI(artificial intelligence) to manage a variety of diseases and predict mortality. In order to analyze vital sign data using AI, it is important to select and extract vital sign data suitable for research purposes. Methods: We developed a method to visualize vital sign and early warning scores by processing retrospective vital sign data collected from EMR(electronic medical records) and patient monitoring devices. The vital sign data used for development were obtained using the open EMR big data MIMIC-III and the wearable patient monitoring device(CareTaker). Data processing and visualization were developed using Python. We used the development results with machine learning to process the prediction of mortality in ICU patients. Results: We calculated NEWS(National Early Warning Score) to understand the patient's condition. Vital sign data with different measurement times and frequencies were sampled at equal time intervals, and missing data were interpolated to reconstruct data. The normal and abnormal states of vital sign were visualized as color-coded graphs. Mortality prediction result with processed data and machine learning was AUC of 0.892. Conclusion: This visualization method will help researchers to easily understand a patient's vital sign status over time and extract the necessary data.