통계적 기법을 이용한 마이크로 스피커 다이아프램의 최적형상설계에 관한 연구

안찬우,홍도관,최재기,박진우 東亞大學校附設 生産技術硏究所 2007 生産技術硏究所硏究論文集 Vol.12 No.-

This study uses response surface methodology to explain correlations between the objective function and design variables, fractional factorial design and central composite design were carried out. The change of shape of diaphragm, thickness of diaphragm and voice coil weight based on fractional factorial design and central composite design are made. Therefore this study carried to decide design variables for minimizing 1st natural frequency and maximizing 2nd natural frequency of diaphragm using response surface methodology and screening(fractional factorial design), we showed improved design variables.

제주도 동남방 신천해안역 해수의 이화학적 특성과 저질분포

최영찬,고기원,김상현 제주대학교 해양연구소 1987 해양자원연구소연구보고 Vol.11 No.-

수퍼차저에 의한 가솔린 機關의 性能에 관한 硏究

김동기,신이건,전봉준,박찬준 서울産業大學校 1995 논문집 Vol.41 No.1

The supercharging characteristics and the combustion performance of the spark iginition engine are investigated through the experiments. The apparatuses used in the experiment are the carburetor type 1468cc Gasoline Engine and the screw type supercharger. A supercharger pulley and a water pump pulley through V-belt are connected to the engine. The diameter of supercharger pulley is 63mm. The diameter of water pump pulley used are 63mm and 135mm,repectively.A optical senser is used to measured the speed of a engine. The pressure in first cylinder is measured. The rate of pressure rise and the rate of heat release are calculated. The engine speed considered is increased by 500rpm from 1500rpm to 3500rpm. It is found that the supercharging characteristics and the combustion performance in case of the engine with supercharger are increased at low speed range. Compared the supercharged engine with the natually aspirated engine, the most effects of supercharging on the torque and the rate of maximium pressure rise are observed at 2000rpm and 1500rpm, respectively.

超傳導 交流 發電機의 電磁 遮蔽 效果에 관한 有限 要素 解釋

南基讚,韓聲鎭,周秀元 동아대학교 공과대학 부설 한국자원개발연구소 1992 硏究報告 Vol.16 No.1

This paper deals with the magnetic shielding effects in the superconductiong a. c. generator using finite element method. Models of three different shields are studied to compare the magnetic shielding effects. Applying 3 phase ac source to the armature, the magnetic flux densities are calculated for directions and frequencies. Because the stability of the superconducting field winding depends on the screening of the magnetic fields, computed results should be used to design the electromagnetic shield of the superconduction generator.

제주도 지하수의 전기비전도도와 염소이온의 지역별 변화 양상

고기원,문영석,최영찬,고용구 제주대학교 해양연구소 1995 해양자원연구소연구보고 Vol.19 No.-

열린교육의 현장 정착을 위한 아이디어 탐색

정찬기오,이광우 경상대학교 1997 學生生活硏究所報 Vol.23 No.-

The objectives of this study are to examine the ideas for adoptation of open education in classroom, and then provide teachers desirable views of open education. The concrete problems in this study are as following : 1) to examine a historical development and practical program of open education. 2) to examine a ideas and views of open education. The method of this study is literature review. To adopt open education in classroom, following should be considered that the relationship of teaching and learning paradigm elements for opening education should keep logical relation, and which should be child-centered objectives, cotents, and method. The relation among teacher-content-learner should keep itself empirical, the learning tasks, contents and learning activities should also be learner-center direct empirical learning. The classroom environment should be decorated to accomplish open education's aims. It is desirable that the effect of interaction among these elements should be maximum. In addition, a crossing met logical relation connected with learning objectives-contents-method and empirical relation connected with teacher-content-learner, is more transfered learners compare to traditional instruction for an open education. as it were, the paradigm should be as centered for learning activities, contents, and teaching method as possible.

액체-고체 순환유동층의 상승관에서 액상의 점도가 고체체류량 및 열전달계수에 미치는 영향

이찬기,강석환,신광식,송평섭,강용,김상돈 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.4

직경이 0.102 m이고 높이가 3.5 m인 액체-고체 순환유동층에서 액체의 점도가 고체입자의 체류량과 열전달계수에 미치는 영향을 검토하였다. 밀도가 2,500 kg/㎥인 유리구슬(d_(p)=1.0, 1.7, 2.1 또는 3.0 mm)과 CMC 용액(μ_(L)=0.96-38 mPas)을 각각 고체상과 액체상으로 사용하였다. 액체-고체 순환유동층에서 고체입자의 체류량은 액체의 유속이나 점도가 증가함에 따라 감소하였고 유동입자의 크기나 입자의 순환속도가 증가함에 따라 증가하였다. 액체-고체 순환유동층에서 열전달계수는 액체의 점도가 증가함에 따라 감소하였고 유동입자의 크기나 순환속도가 증가함에 따라 증가하였으나, 액체의 유속이 증가함에 따라서는 큰 변화가 없었다. 액체-고체 순환유동층에서 고체입자의 체류량과 열전달계수는 다음과 같이 실험변수와 무차원군에 의해 상관식으로 얻을 수 있었다. E_(S) = 0.783U^(-0.100)_(L)G^(0.164)_(S)d^(0.302)_(p)μ^(-0.036)_(L) h = 4349.3U^(0.010)_(L)G^(0.099)_(S)d^(0.151)_(p)μ^(-0.015)_(L) ◁그림삽입▷ Effects of liquid viscosity on the solid holdup and heat transfer coefficient have been investigated in the riser of a liquid-solid circulating fluidized beds, whose diameter is 0.102 m and 3.5 m in height. Glass beads (d_(p)=1.0, 1.7, 2.1 or 3.0 ㎜) whose density is 2,500 ㎏/㎥ and aqueous solutions of carboxymethy cellulose (CMC)(μ_(L)=0.96-38 mPas) have been used as the solid and liquid phase, respectively. It has been found that the solid holdup decreases with increasing liquid velocity or viscosity, but it increases with increasing solid particle size or solid circulation rate. The heat transfer coefficient decreases with increasing liquid viscosity but it increases with increasing particle size or solid circulation rate, however, it does not change considerablely with increasing liquid velocity. The solid holdup and heat transfer coefficient have been well correlated in terms of operating variables or dimensionless groups as fellow: ◁수식원문참조▷

객체-관계 매핑 프레임워크 성능 측정

박기남,김영찬 한밭대학교 정보통신전문대학원 2005 정보통신전문대학원 논문집 Vol.3 No.1

최근 들어 소프트웨어 개발 언어에서는 객체지향 언어(JAVA, C# 등)들이 점차 주목을 받고 있다. 하지만 대부분의 영구 데이터 저장 장소로 관계형 데이터베이스(RDB)를 사용하고 있고, 이에 따라 관계형 데이터베이스와 객체지향 언어를 같이 사용하기에 많은 어려움이 따르며, 관계형 데이터를 객체형 데이터로 바꾸는데 많은 개발 시간을 요하게 된다. 이와 같은 문제점을 해결하기 위하여 관계형 데이터와 객체형 데이터 간의 변환을 지원하기 위한 많은 프레임워크(Hibernate, JDO, Castor 등)들이 속속 등장하였다. 본 논문에서는 객체관계 프레임워크(ORM Frameworks)중에서 Hibernate를 사용한 Pet Store와, EJB를 사용한 Pet Store를 구현하여 각각의 Database Access속도와, 코딩양들을 비교 분석 하여 본다. Object-oriented languages such as C++, Java or C# are getting attention gradually as software development languages recently while relational databases which have been around since the 1960s have remained as primary databases. Writing an object-oriented application that stores data in a relational database set developers up for a large maintenance burden because there is an impedance mismatch between object model and relational model. To alleviate such problem, it is recommended to use the persistent framework. The persistent frameworks can allow developers to map normal objects to relational tables with minimal effort. As a result, a lot of frameworks such as Hibernate, JDO, and EJB appeared successively. In this paper, we benchmark the Hibernate and EJB frameworks using Java Pet Store which is a de facto reference implementation provided by Sun.

근대 계몽기 전(傳) 양식의 향방 : '내면'의 형성과 '悖德'의 표출 양상을 중심으로

김찬기 현대문학이론학회 2003 現代文學理論硏究 Vol.0 No.19

In this paper I examined the accommodation of the interior of a man and immorality in Kimbongboncho^n, the forth story of Sindon Gongan and Obokso^ncho^n, the seventh story of the same work. By doing this, I tried to make value of the literary position of the two stories in the discourse of national enlightenment in the Korean enlightenment period. I also tried to illuminate the fact that the legendary tales accommodated in the two stories were not aimed to the mere esthetics of a simple trickery. As a result, I presented two assertions. First, "Cho^n" works in the Korean enlightenment period reflected the changes of the people's sense of value of the time and thus made an attention to concrete emotion of an individual. Second, "Cho^n" works as a traditional literary form created modern interior of a man by admitting the presence of immorality.

『한성순보』 소재 「亞里斯多得里傳」에 관한 연구

김찬기 현대문학이론학회 2004 現代文學理論硏究 Vol.0 No.21

In this paper, I tried to investigate the characteristic of a ‘Aristoteles-cho^n(亞里斯多得里傳)’ written in the Korean enlightenment period. I mainly focused on the usage of the word, 'Literature' in the writings from the late nineteenth centure to the beginning of 1900 and in this works, and the specific narration method. The narration method of 'Aristoteles-cho^n(亞里斯多得里傳)' indicates the fact that a "cho^n" became a very long story in the enlightenment period, especially by using the specific way of narration that could be abbreviated as showing facts and giving comments on them. A "Cho^n" had changed to be long not only because it was affected by the Western biography but also because the narration method of "Cho^n" had changed like above. In addition, 'Aristoteles-cho^n(亞里斯多得里傳)‘ reflects the affection of a historical biography of the enlightenment period on the formation of a modern historical novel.