Aspen Plus 프로그램에 의한 장갑차량용 고온고분자전해질 연료전지 기반 보조전원장치 성능 시뮬레이션 분석

유민규,박지일,권혁상,Yu, Minkyu,Park, Ji-il,Kwon, Hyuksang 한국군사과학기술학회 2016 한국군사과학기술학회지 Vol.19 No.2

The fuel cell based auxiliary power unit (APU) is promising for power source of armed vehicles due to its silence and high efficiency. Especially, the on board hydrogen generation and fed to fuel cell system was core technology of this power system. In this study, we analyzed the performance of the Auto thermal reactor (ATR) that produce the hydrogen from the fuel, integrated High temperature polymer electrolyte fuel cell (HT-PEFC) by Aspen plus software. The fuel was designed as a n-dodecane for analysis of military fuel (JP-8).

학교차원의 긍정적 행동중재와 지원(PBIS) 체계 적용에 대한 중등 특수교사의 인식

강성구(Kang, Seonggoo),권혁상(Kwon, Hyuksang),임경원(Lim, Kyoungwon),곽승철(Kwak, Seungchul) 학습자중심교과교육학회 2020 학습자중심교과교육연구 Vol.20 No.1

이 연구는 학교차원의 긍정적 행동중재와 지원(PBIS: Positive Behavior Intervention & Support) 적용에 대한 중등 특수교사의 인식을 알아보고자 전국의 141명의 중등 특수교사를 대상으로 2018년 7월에 조사를 실시하였으며, 조사결과는 기술통계와 다변량 공분산분석(MANCOVA)으로 분석하였다. 연구문제에 따른 분석의 결과 첫째, 학생의 행동문제 중재와 지원에는 교사의 개별적인 지원보다 다양한 구성원을 갖추고 전문가가 참여하는 학교차원의 별도의 팀 구성을 통한 지원이 필요하다고 인식하고 있었으나, 이 밖에 계획 및 평가, 실행, 실행지원의 세부 적용요소 사이에는 분명한 긍정 또는 부정의 인식은 나타나지 않았다. 둘째, 조사 참여자의 근무기관과 교육경력에 따른 학교차원의 PBIS 인식의 별다른 의미 있는 차이도 나타나지 않았다. 이를 통해 볼 때 학교차원의 PBIS의 적용 시 일선 교사들은 특수학급 및 특수학교 등의 적용 상황의 차이 없이 ‘긍정적 행동지원팀 설치’가 필요하다고 인식하고 있었으나, 학교차원의 PBIS 적용이 학교체계 변화로 이어진다는 인식은 명확히 하고 있지 못하는 것으로 유추된다. 결론적으로 다층지원체계에 기반을 둔 학교차원의 PBIS의 실질적인 적용을 위해서는 학교 내 부서 및 전담 조직설치 등의 학교 체계 전반적인 변화가 필수적이라는 인식의 전환이 필요하며, 개별적인 연수 이상의 체계적인 국가적 정책 추진 및 관련 연구 수행, 연구학교 운영 등이 함께 수반되어야 한다. 학교차원의 PBIS의 적용은 우리나라 학생 행동 문제 관리 및 지원의 근본적인 변화의 계기가 될 것이다. The purpose of this study was to examine the special education teachers perceptions on School-Wide Positive Behaviour Intervention and Support(School-wide PBIS) in order to suggest the methods of successful positive behaviour support in South Korean special education settings. Questionnaires were distributed to 150 special education teachers, and 141 of those questionaries were analyzed to examine their perceptions by descriptive statistics and multivariate analysis of covariance(MANCOVA). The study results are as follow: First, the formation of positive behavior support team within special education settings was perceived the most important area among special education teachers, whereas not much of statistical differences were found in the areas, such as planning, evaluation, application, and supports. Through this, special teachers in the field recognized the need to apply school-wide PBIS to special education sites without any difference between special classes and special schools. According to this, special education teachers recognized the necessity of establishing positive behavior support team without any difference in the application of special classes and special schools when applying the school-wide PBIS, but the application of the school-wide PBIS leads to changes in the school system. It is inferred that perception is not clear. In conclusion, it is necessary to change the perception that the overall change of the school system, such as the establishment of departments and dedicated organizations, is essential for the practical application of the school-wide PBIS based on the multi-layered support system. In addition, it should be accompanied by systematic national policy promotion, conducting relevant research, and action research at school beyond individual teacher training. The application of school-wide PBIS will be an opportunity for fundamental changes in the management and support of student behavior problems in South Korea.

군용 연료전지 적용을 위한 Mg-Graphite 펠렛의 가수분해 반응을 이용한 수소생산

박민선,유민규,김종수,권혁상,Park, Minsun,Yu, Minkyu,Kim, Jongsoo,Kwon, Hyuksang 한국군사과학기술학회 2015 한국군사과학기술학회지 Vol.18 No.2

On board hydrogen generation from the hydrolysis of an active metal is very attractive due to its economical, convenient, and safe reasons. A Mg-graphite pellet has been designed as a hydrogen source for portable fuel cell. Mg (1 g) + 0.10 g graphite pellet showed an excellent hydrogen generation rate that is equivalent to 15.8 ml/g.min from its hydrolysis. The hydrogen generation rate of the pellet is significantly increased due to the galvanic corrosion by galvanic cells between Mg anode and graphite cathode in a 10.wt. % NaCl solution at a room temperature.

제2형 당뇨병을 동반한 국내 고도비만 환자에서 대사비만 수술의 효과

이홍찬(Hongchan Lee),김미경(Mikyoung Kim),권혁상(Hyuksang Kwon),송기호(Kiho Song),김응국(Eungkook Kim) 대한외과학회 2010 Annals of Surgical Treatment and Research(ASRT) Vol.79 No.1

Purpose: Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic adjustable gastric banding (LAGB) are the most effective intervention and cure in achieving sustained weight loss in the morbidly obese with co-morbities, especially in type 2 diabetes mellitus (DM). Currently, there are few data in the literature presenting early diabetic outcomes between the 2 major bariatric surgeries in Korea. The aim of this study is to observe weight loss, improvement of type 2 DM after LRYGB and LAGB. Methods: 33 retrospective data were obtained from diabetic subjects undergoing LRYGB (n=53) and LAGB (n=77). These measurements included age, sex, body mass index (BMI), pre-operative diabetic duration, post-operative diabetic at follow-up visit after surgery. Paired t-test, and SPSS12.0 were used for statistical analysis. Results: 33 morbidly obese patients with type 2 DM who had both procedures complain of general weakness. Most patients were taking oral medications or insulin and tired of them. Pre and post-op 12 months of percent of excess weight loss (%EWL), fetal bovine serum (FBS), hemoglobin A1c (HbA1C) presented at 0%, 185.6 ㎎/㎗, 8.7% and 70.6%, 123.4 ㎎/㎗, 6.6% in patients who had LRYGB (P<0.05). Pre and post-op 12 months of %EWL, FBS, HbA1C presented at 0%, 180.6 ㎎/㎗, 8.4% and 32.8%, 136.5 ㎎/㎗, 6.8% in patients who had LAGB (P<0.05). Rate of discontinuance or decreasing for treatment of type 2 DM after surgery showed 94% for LRYGB versus 80% for LAGB, and unchanged rates were 6% versus 20%, respectively. Conclusion: This study showed LRYGB and LAGB are quite satisfactory and promising bariatric procedures with significant weight loss and improvement of type 2 DM in Koreans. LRYGB is significantly associated with more weight loss, more diabetic outcome than LAGB. Clinical experiences in Korea with both procedures are limited and a larger number of cases are need, but the recent data shows promising results that are comparable to the international experience.

아황산나트륨을 이용한 스프링클러 동배관 공식 부식 방지

서상희 ( Sang Hee Suh ),서영준 ( Youngjoon Suh ),권혁상 ( Hyuksang Kwon ) 한국부식방식학회(구 한국부식학회) 2017 Corrosion Science and Technology Vol.16 No.5

Inhibition of pitting corrosion of the copper sprinkler tubes by removing dissolved oxygen in water with sodium sulfite was studied on the wet sprinkler systems operated in 258 household sites. First, air in the sprinkler tubing was removed by vacuum pumping. The tube was then filled with sodium sulfite dissolved in water. Sodium sulfite was very effective in maintaining a very low dissolved oxygen concentration in water in the sprinkler tube for the observation period of six months. Water leakage from the copper sprinkler tube was reduced significantly by using sodium sulfite. Both pitting corrosion process and pitting corrosion inhibition mechanism were investigated by examining microscopical and structural aspects of corrosion pits formed in failed copper sprinkler tube. Pitting corrosion was caused by pressurized air as well as sediments such as sand particles in copper tubes through oxygen concentration cells. It was confirmed microscopically that growth of corrosion pits was stopped by reducing dissolved oxygen concentration to a very level by using sodium sulfite.

스프링클러 구리배관의 공식 파손 억제

서상희 ( Sang Hee Suh ),서영준 ( Youngjoon Suh ),이종혁 ( Jonghyuk Lee ),권혁상 ( Hyuksang Kwon ) 한국부식방식학회(구 한국부식학회) 2020 Corrosion Science and Technology Vol.19 No.2

The inhibition of pitting corrosion failure of copper sprinkler tubes in wet sprinkler systems was studied. First, an apparatus and technology for removing air in the sprinkler tubes by vacuum pumping and then filling the tubes with water were developed. Using this apparatus and technology, three methods for inhibiting the pitting corrosion of the copper sprinkler tubes installed in several apartment complexes were tested. The first one was filling the sprinkler tubes with water bubbled by high-pressure nitrogen gas to reduce the dissolved oxygen concentration to lower than 2 ppm. In the second method, the dissolved oxygen concentration of water was further reduced to lower than 0.01 ppm by sodium sulfite. In the third method, the sprinkler tubes were filled with benzotriazole (BTAH) dissolved in water. The third method was the most effective, reducing the failure frequency of the sprinkler tubes due to pitting corrosion by more than 80%. X-ray photoelectron spectroscopy analyses confirmed that a Cu-BTA layer was well coated on the inside surface of the corrosion pit, protecting it from corrosion. A potentiodynamic polarization test showed that BTAH should be very effective in reducing the corrosion rate of copper in the acidic environment of the corrosion pit.

Fabrication of porous Co-P foam by electrodeposition for an efficient electrocatalyst

SeKwon Oh(오세권),MinJoong Kim(김민중),EunAe Cho(조은애),HyukSang Kwon(권혁상) 한국신재생에너지학회 2016 한국신재생에너지학회 학술대회논문집 Vol.2016 No.5