인산형 연료전지에 관한 연구 : 다공성전극의 전기화학적 산소환원 Electrochemical Reduction of Oxygen on Porous Electrode

이주성,박정일,유덕영 한국화학공학회 1990 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.28 No.4

인산형 연료전지용 다공성전극에 대한 전기화학적인 산소환원 특성을 고찰하였다. 테프론 양은 카본블랙 무게비로 환산하여 기체확산층은 40%, 촉매층에서는 30%인 때가 적당하였다. 기체확산층에 사용된 발포제인 탄산수소암모늄의 양은 카본블랙 무게비에 대하여 600%일 때가 좋았으며 이 때 다공율 60-65% 평균구경 20-3O㎛이었다. 촉매충의 카본블랙에 함침시킨 백금촉매의 최적량은 전극단위 면적당 0.5㎎이었다. 이 조건에서 만든 전극의 산소환원 전류밀도는 0.7V(vs. NHE)에서 20㎃/㎠를 나타냈다. The electrochemical characteristics of oxygen reduction of a porous electrode for phosphoric acid fuel cell have been studied. The best result for the manufacturing of fuel cell electrode was obtained when the amounts of PTFE contained in the catalytic layer and in the gas diffusion layer were 30% and 40%, respectively. The gas diffusion layer had the porosity of 60-65% and mean pore-diameter of 20-30㎛ when the foaming agent(ammonium bicarbonate) to the carbon black was 600wt%. The optimum amount of platinum catalyst impregnated in carbon black was 0.5㎎/㎠. At these conditions, cathode current density was 240㎃/㎠ at 0.7V(vs. NHE).

지방의료원의 재무성과에 영향을 미치는 요인에 관한 연구

이주성 한국교통대학교 2020 한국교통대학교 논문집 Vol.55 No.-

The regional public hospital refers to a hospital established by a local government, a city or a province, for public health care of local residents. The regional public hospital is responsible for providing high-quality medical care, as well as medical safety network functions such as infectious disease response, emergency, and medical disaster preparation, as well as medical care for medical patients and homeless people. The purpose of this study is to present a plan to enhance the competitiveness and profitability of regional public hospitals by empirically analyzing factors affecting the financial performance of regional public hospitals. This study analyzed financial statements and other data for the five years from 2015 to 2019, targeting 34 regional public hospitals located in major regions of the country as of December 31, 2019. The collected data were analyzed by using IBM SPSS Statistics 25 program. The results of this study are summarized as follows. First, the average financial index of regional public hospitals in the past five years is -0.76% for net profit ratio of medical revenue, -5.71% for ROA, 842 million won for average monthly medical revenue per 100 beds, 129.66% for dependence on others' capital, 1.74 times for total asset turnover, 10.53% for medical return growth rate, -5.82% for total asset growth rate, 3.72% for medical revenue ratio of operating cash flow. Second, the factors that have positive (+) influence on the net profit ratio of medical revenue were the opening period, the number of manpower per 100 beds, the total asset turnover ratio, the increase ratio of medical revenue, the medical revenue ratio of operating cash flow. Third, the factors that have positive(+) influence on the ROA were the opening period, the number of manpower per 100 beds, and the medical revenue ratio of operating cash flow. Fourth, the factors that positively affect the average monthly medical revenue per 100 beds were the number of manpower per 100 beds, total asset turnover, and the medical revenue ratio of operating cash flow. The factors that have a significant negative(-) influence were the dependence on others' capital.

대학생의 심리적 특성이 회계학 학업성취도에 미치는 영향

이주성 한국상업교육학회 2011 상업교육연구 Vol.25 No.4

이 연구의 목적은 교육심리학적 측면에서 대학생들의 성격유형과 학습태도 등의 심리적 특성이 회계학 학업성취도에 미치는 영향을 실증적으로 분석하는데 있다. 즉, 대학생의 성격유형이 학습태도에, 학습태도가 회계학 학업성취도에, 성격유형이 회계학 학업성취도에 영향을 미치는지 세 가지 가설을 설정하여 검증하였다. 회계학을 수강한 대학생 172명을 대상으로 MBTI 성격유형검사와 학습태도 설문조사를 하고, 학업성취도는 회계학 평점평균으로 하였다. 요인분석을 통해 자율학습, 학습적 자신감, 주의집중도, 학습방법, 교수에 대한 태도 등을 학습태도변수로 하였다. 자료는 SPSS Statistics 18.0을 통해 빈도분석, 교차분석, 요인분석, t-검정, 회귀분석을 하였다. 연구결과, 대학생들의 성격유형은 학습태도와 회계학 학업성취도에 영향을 미치며, 학습태도도 회계학 학업성취도에 영향을 미친다는 것이다. 따라서 대학생들은 회계학을 학습할 때 자기 성격유형에 맞는 학습태도를 견지하여 학습한다면 학업성취도 또한 높아질 수 있다는 점을 시사해 준다고 할 수 있다. This study examined the effects of university students' personality type and learning attitude to the scholastic achievement in accounting. The participants in this study were 172 undergraduate students taking accounting courses. Seventy-eight (45.3%) of the subjects were male while ninety-four(54.7%) were female. Subjects of this study were given the MBTI and Attitudes scale questionnaire. The analysis of results has been performed using SPSS(PASW) Statistics 18.0 for frequency, Factor Analysis, t-test, multiple regression. The results of this research suggest that the personality type of MBTI do affect the students' learning attitude, and the students' learning attitude do affect the scholastic achievement in accounting. These results contributes to the identification of learner characteristics that may predict success in accounting learning.

[동요] 지명 노래

이주성 한글학회 1942 한글 Vol.- No.93

On the Structural Analysis Using the Isogeometry Analysis Approach

이주성,장경식,노명일,Lee, Joo-Sung,Chang, Kyoung-Sik,Roh, Myoung-Il Computational Structural Engineering Institute of 2011 한국전산구조공학회논문집 Vol.24 No.1

본 논문에서는 NURBS의 기저함수를 이용하는 등기하 해석을 선형 탄성 문제에 적용하였다. 등기하 해석의 목적은 기하학적 모델링 (CAD)와 수치적 해석 (CAE)를 통합하는 것인데, 이는 계산 망으로써 NURBS에 의한 기하학적 모델링 결과를 직접 이용해서 이룰 수 있다. NURBS 곡면은 조정점과 노트 벡터들을 이용하여 정확한 기하학적 형상을 표현할 수 있으며, 또한 요소의 정밀화 과정이 상대적으로 용이하다는 장점이 있다. 본 연구를 통해 개발된 컴퓨터 코드의 정당성을 보이기 위해 비교적 단순한 형태의 두 가지 구조모델에 적용하였다 ; 1) 균일 내압을 받는 실린더, 2) 균일 인장력이 작용하는 중앙에 구멍이 있는 정사각형 판. 이 두 모델은 정해가 있는 경우로서 절점을 추가하는 h-정밀화와 기저함수의 차수를 증가하는 p-정밀화에 의한 등기하 해석법을 적용한 근사해의 수렴성을 분석하였다. In the present work, isogeometric analysis in linear elasticity problem is conducted using the basis functions from NURBS. The objectives of isogeometric analysis introduced is to integrate both geometric modeling(CAD) and computational analysis(CAE), and this can be accomplished from direct usage of geometric modeling by NURBS as the computational mesh. The merit of the isogeometry analysis is that NURBS surface are able to represent exact geometry from the control points and knot vectors, and also subsequent refinement is relatively simple relatively. In order to verify the computer codes developed in this study, it has been applied to two structural models of which geometry are simple ; 1) circular cylinder subjected to the constant internal pressure loading, 2) square plate with circular hole at center subjected to uniform tension. The exact solutions of these two models are available. Convergence of the approximate solutions by the present code for the isogeometry analysis are investigated by mesh refinement with inserting knots (h-refinement) and by mesh refinement with order elevation of the basis functions (p-refinement).

우리나라의 산림정책과 목재수급 ( Forestry Policy and Wood Supply and Demand in Korea )

이주성 한국펄프·종이공학회 1987 펄프.종이技術 Vol.19 No.3

고유변형률 기반 등가하중법을 이용한 판의 용접변형 해석

이주성,Lee, Joo-Sung 대한용접접합학회 2010 대한용접·접합학회지 Vol.28 No.2

IIn this study, used is the equivalent loading method based on the inherent strain to predict the welding deformation of panel members. Equivalent loads are computed from the inherent strain distribution around weld line, and then applied for the linear finite element analysis. Thermal deformation of panel members can be, of course, carried out through the rigorous thermal elasto-plastic analysis procedure but it is not practical in applying to predicting the welding deformation of large structures such as blocks found in a ship structure from view of computing time. The present equivalent load approach has been applied to flat plate model to verify the present approach, and to several curved plate models having the curvature in the welding direction to investigate the effect of the longitudinal curvature upon the weld-induced deformation. The results are compared with those by thermal elasto-plastic analysis. As far as the present results are concerned, it can be said that the present approach shows good agreement with the results by welding experiment and the rigorous thermal elasto-plastic analysis. The present approach has been also applied to predict the welding deformation of panel block as for application illustration to practical model.

우리나라의 환경회계에 관한 연구

이주성 충주대학교 2006 한국교통대학교 논문집 Vol.41 No.-

Recently, environmental issues are recognized as serious problems within an industrial world as well as among governments, environmental activists, and international agents. And the needs of the environmental accounting informations are growing rapidly. According to the Financial Accounting Standards revised in 1997, Korean corporations were required to disclosure the environmental informations as additional footnote. Especially, The Ministry of Environment published 「2004 Environmental Reporting Guidelines」 and 「2004 Environmental Cost Accounting Guidelines」. The purpose of this study is to suggest the improvement of disclosure system of environmental accounting in Korea. To accomplish this objective, this study reviewed the existing relevant studies and literatures. By the results of the study, I suggested some improvements for two aspects of environmental accounting and environment related guideline. The findings of this study will contribute to the settlement and development of the environmental reports in Korea.

A Flexible Chain-based Screw Propeller for Capsule Endoscopes

이주성,김병규,홍예선 한국정밀공학회 2009 International Journal of Precision Engineering and Vol. No.

In this paper, a new type of screw propeller for capsule endoscopes is introduced whose rotation motion is enforced by magnetic forces between an armature magnet inside the capsule and an external rotating permanent magnet working like an AC stator. The screw propeller consists of flexible threads attached on the capsule body. The spiral angle of the flexible threads switches automatically due to the friction force between intestine wall and the capsule body when the rotating direction of the capsule body is reversed. Therefore, the moving direction of the capsule is independent of the rotating direction of the capsule body. This will help the capsule advance especially in curved tracts by changing its effective thread angle for reduction of friction torque. In order to investigate main parameters that influence the performance of the new screw propeller, we evaluated the speed of the capsule with various shapes and sizes of the flexible threads, changing the parameters such as rotational speed of the external permanent magnet, distance between the external magnet and the armature magnet inside the capsule, and viscosity of lubrication oil in artificial intestine tract. The speed of the capsule with the flexible screw propeller was mainly dependent on the shape of threads. Also, the distance between the magnets highly influenced the speed of the capsule since thrust force of the capsule was dependent on it. On the contrary, rotational speed and oil viscosity insignificantly contributed to the speed of the capsule. Especially in curved tracts, the effective thread angle of the screw propeller which could be changed by its rotation direction played a great role in advancing the capsule efficiently.

국제화시대 공과대학의 역할과 요망

이주성 한국공학교육학회 1994 Ingenium(人材니움) Vol.1 No.2