라디안의 속성에 관한 연구 : 1rad 은 각인가 실수인가?

김완재 대한수학교육학회 2009 수학교육학연구 Vol.19 No.3

Despite the many discussions of mathe- matics education, there are a lot of controversy of the Radian. Generally, Radian is taken to have two properties. One property is an angular property and other is a property of pure numbers. For this reason, both Students and teachers are hard to understand the radian. This study is to provide a base of the radian understand. In essence, radian has only angular property, and other property is a derived property. So radian is to be understood in an angle. 라디안에 관한 많은 교육적 논의에도 불구하고 교수자나 학습자 모두에게 라디안은 쉽지 않은 개념으로 받아들여지고 있다. 이러한 상황은 라디안에 대한 본질적 이해에 대한 수학적 연구의 부족에서 일차적인 이유를 찾을 수 있을 것이다. 또한 물리학에서의 편의성을 위한 ‘무차원 단위로서의 라디안’ 이라는 개념에 얽매여 수학적 연구에 있어서의 고정관념을 형성하고 있는 것이 또 다른 이유로 보인다. 마지막으로 대학과정의 고등수학에서 다뤄지는 삼각함수의 개념들을 엄밀히 분석하고 이해하지 않은 채로 중등학습에 그 개념들을 도입하려는 과정에서 또 다른 문제점들이 발생하고 있는 것으로 파악된다. 이에 본 연구에서는 라디안의 본질적 속성과 더불어 여러 오개념들에 대한 이론적 연구를 통해 라디안에 대한 이해를 돕고자 하며, 나아가 라디안 개념 지도에 있어서의 도움을 제시하고자 한다.

‘디지털 트윈’ 개념 적용한 가스터빈 발전소 운영관리시스템 기술

김완재 전력문화사 2018 Electric Power Vol.12 No.1

Effects of α-Lipoic Acid Supplementation on Malondialdehyde Contents and Superoxide Dismutase in Rat Skeletal Muscles

김완재,강준용,권대근,송영주,이광호 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.4

This study investigated the effects of α-lipoic acid (ALA) supplementation on the malondialdehyde (MDA) contents and superoxide dismutase (SOD) protein expression in rat skeletal muscles under non-exercising condition. Fourteen Sprague-Dawley male rats at the age of 6 weeks were randomly divided into 2 groups CS,(normal diet group, n=7) and AS (0.5% ALA supplemented diet group, n=7), and keep non-exercising condition for 4weeks. The muscle MDA concentration of the AS group was significantly lower than that of the CS group in the both soleus and extensor digitorum longus muscles. The expressions of Cu/Zn-SOD and Mn-SOD proteins in the soleus muscle were significantly higher in the AS group than that in the CS group. From these results, ALA supplementation under non-exercising condition had a role in increasing of antioxidant enzymes in skeletal muscle types of rats.

창업자 특성과 소기업 사업성과 간 관계에 관한 연구

김완재,정화영,Kim, Wan-Jae,Chung, Hwa-Young 한국벤처창업학회 2007 벤처창업연구 Vol.2 No.3

This study alms to analyze the entrepreneur characteristics of founder on enterprise performance from the strategic viewpoint as well as features of founder of small firms such as background feature of founder, psychological features and management skill. As considered by Background features of founder include educational background of founder, his experience in business creation, consultation or course related to business creation. This study verified the effects of factor which business performance (financial, non financial) on small firms. Also, this study considered psychological features of founder include achievement desire, risk-free propensity, level of patience on vagueness and control position. And it analyzed that between such factors and performance of small firms were examined in related. In the mean time, management ability of founder, entrepreneur ability, technical and function ability were considered for management skill of founder and alalyzed effect of the factors on performance of small firm were examined. Effects of strategic intention of founder of small firm were analyzed by the strategic viewpoint. At this time, strategy of small firm was divided into product-service reform differentiation strategy, marketing differentiation strategy and cost leadership strategy. This study distributed questionnaire on CEO of small firms in Daejeon and Chungnam area for accomplish the study objective and it collected a total of 145 copies of questionnaires. As a result of analyzing collected questionnaire, this study deduced the following study results and suggestions. First, results different from those of existing studies were found Since sales, net income and profit rate of small firm were not high cause economic depression on the whole. Second, entrepreneur ability was found to be required for success of business creation. Entrepreneur ability of founder was the factor that affects both financial and non - financial performance of small firm. As such, entrepreneur ability can be regarded as the most important factor for success in business creation of small firm. Accordingly, entrepreneur ability is the most important source for success in business creation of small firm. Third, strategy of small firm was found to be the important factor that affects the non-financial performance even if it could not give significant effects on financial performance. Thus, product service reform differentiation strategy, marketing differentiation strategy and cost leadership strategy have significant effects on non - financial performance of small firm. Accordingly, it is required to operate small firm with strategic mind - set for small firm to achieve success. This study analyzed the effects of feature of founder and strategy of small firm on business performance of small firm through practical analysis on small firms in Daejeon and Chungnam area, and deduced meaningful results. However, Since this study collected data on small firms in Daejeon and Chungnam only, there is a limit in generalizing the results of this study to all small firms in Korea. Companies answering to this questionnaire process were mainly wholesale and retail service companies. In addition, there is a limit in that it failed to analyze feature of representative type of industry due to limit in number of sample, it is required to divide representative type of industry and to compare and analyze types of industry in future studies.

창업자 특성과 소기업 사업성과 간 관계에 관한 연구

김완재,정화영 한국벤처창업학회 2007 한국벤처창업학회 학술대회 Vol.2007 No.4

자연대류 열전달을 고려한 해상 풍력 변압기실 환기 설계

김완재(Wanjae Kim),김광수(Kwang Soo Kim),이상민(Sang Min Lee),최우성(Woo Sung Choi) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.6

1 방 밴드와 어댑터를 사용하여 구성한 겹완철 장주의 응력 및 피로해석

김완재(Wanjae Kim),이기철(Lee Kichul),황수천(Hwang Soo-chun),이건욱(Lee Gun-uk) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.10

Power pole and its components mainly support and shift power cable and its direction to properly distribute electric power to the need. Power pole assembly includes such components as supporting pole, crossarms, bands for crossarms and insulators. Considerable portion of external force are to be applied to crossarms and bands which connect crossarms to the poles. One-directional bands, 1D bands, are used for single crossarms and two-directional bands, 2D bands, for double cross arms. In the case of replacing a single crossarm by double crossarms, a band also has to be changed to a 2D band. Since replacing bands require a lot of work, a suggestion which utilize adapters to install double bands without the replacement of bands is made. This paper compares the results of stress and fatigue analysis of double crossarms with 1D band and adapter and double crossarms with 2D bands by finite element analysis. Finally structural integrity of the two structures are evaluated and then compared.

해양성 광천수의 암세포 성장, 전이 및 신생 혈관 생성 억제 효과

김완재 ( Wan Jae Kim ),리화 ( Hua Li ),윤택준 ( Taek Joon Yoon ),심재만 ( Jae Man Sim ),최선강 ( Seon Kang Choi ),이광호 ( Kwang Ho Lee ) 한국식품영양학회 2009 韓國食品營養學會誌 Vol.22 No.4

Brine mineral water(BMW) has recently gained attention as a new water resource due to its biological activities. In this study, BMW from the Geumjin area(Gangneung-city, Korea) was evaluated for its growth inhibition, anti-metastasis and anti-angiogenesis activity against cancer cells. The in vitro cytotoxicity was measured by CCK assay, and the anti-metastasis activity was estimated by lung metastasis in vivo. The in vitro incubation of mouse splenic cells with BMW that had been diluted more than 4-fold showed no effect on the cell growth when compared to a control group. Additionally, BMW inhibited the growth of the EL-4, L5178Y-R and colon26-M3.1 cancer cell lines in a dose-dependent manner. In vivo evaluation of the anti-metastasis activity of BMW in BALB/c mice inoculated with the colon26-M3.1 cell line revealed dose-dependent inhibition in response to treatment with samples that were diluted by up to 9 times. Finally, treatment with BMW effectively suppressed the growth of vascular endothelial growth factor(VEGF) added human umbilical vein endothelial cells. Overall, these results suggest that BMW has anti-cancer activity.

Saccharomyces cerevisiae 변이주 세포벽 유래의 베타글루칸의 면역활성 및 Cisplatin과의 병용에 의한 항암 상승작용

김완재 ( Wan Jae Kim ),윤택준 ( Taek Joon Yoon ),김동우 ( Dong Woo Kim ),문원국 ( Won Kook Moon ),이광호 ( Kwang Ho Lee ) 한국식품영양학회 2010 韓國食品營養學會誌 Vol.23 No.2

Cisplatin(ctr-diamminedichlorop1atium) is one of the most effective anti-cancer drugs being clinically used in the treatment of solid tumors. Despite its therapeutic benefits, its use in clinical practice is often limited because of dose related toxicity. It is known that yeast cell wall beta-glucans possess immuno-modulating properties, which allows for their application in antitumor therapy. 1S2 is a kind of beta-glucan derived from the cell wall of mutated Sacchammyces cerevisiae, which exhibits anti-cancer activity in vitro and in vivo. The present study explored the possibility of combination therapy of IS2 with cisplatin. In experimental metastasis of colon26M3.1 cells, prophylactic intravenous administration of IS-2 in combination with cisplatin effectively inhibited tumor metastasis compared with cisplatin alone or IS-2 treatment in vivo. IS-2 effectively enhanced Thl type cytokines including IFN-r, IL-2, ILf2 and GM-CSF. Simultaneously, this combined treatment inhibited production of Th2 type cytokines compared with control. These results suggested that IS-2 can be applied in combination therapy with anti-cancer drugs to minimize their side effects.

스파이럴 강관 제작의 유한요소해석

김완재(Wanjae Kim),김건탁(Kuntak Kim),임세영(Seyoung Im) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

Spiral seam welding pipes are manufactured in two consecutive processes: forming and welding. These processes are analyzed via finite element method to calculate the deformation and stress occurring from the two steps of manufacturing process. The ultimate goal is to find the effect of the plastic deformation resulting from the pipe forming on the residual stress.