셀룰러 망에서 이동국 속도와 방향성을 고려한 효율적인 핸드오프율

정역석,류명춘,오주환 경운대학교 산업기술연구소 2001 産業技術硏究論文誌 Vol.3 No.2(B)

In this paper we model each cell as a set of the triangle and present the handoff area using a subset of the triangle. So, handoff area can be presented depending on radius-division degree of a cell easily. we predict that a mobile station can go our or not the current cell depending on mobile station' speed, direction. We propose a calculation method of handoff rate and handoff call number using the mobile station' moving speed, direction.

E. Zola에 나타난 19世紀 後半期의 社會와 個人 : Les Rougon-Macquart를 中心으로

鄭明煥 서울대학교 교양과정부 1974 論文集 Vol.6 No.-

이 논문의 목적은 Zola의 사회사상, 더욱 구체적으로 말하면 사회내존재로서의 인간에 관 한 그의 사상이 Les Rougon-Macquart 에서 어떻게 전개되어 있는가를 살펴보려는데 있다 20권의 소설을 포함하는 이 거작에는 Zola자신에 의해서《Histoire naturelle et sociale d'unefamille sous le Second Empire》라는 부제가 붙혀져 있다. 그러니까 그 시대적배경은 Napoleon 3세가 지배하딘 1850-70年 사이가 되는 것이지만, Zola가 이 작품들을 실제로 쓴 기간은보불전쟁의 결과로 프랑스에 제3공화국이 수립된 이후인 1871~1893년 이다. (11 이와같이 소설의 배경을 이루는 시대와 그것을 제작한 시대가 다만 시간적인 면에서만 아니라 정치체제에 있어서도 다르다는 사실은 우리로 하여금 적어도 다음과 같은 두가지 가능성을 감안케한다

MOCVD법에 의한 광 통신용 1.55㎛ PBH-DFB 레이저 다이오드 제작

오환술,김중연,전현성,강명구 건국대학교 산업기술연구원 1997 건국기술연구논문지 Vol.22 No.-

DC-PBHDFB LD operating at 1.55㎛ were fabricated by 3-step MOCVD process. The first-order grating with 2370Å period and 700Å etching depth was formed by holographic lithography and wet etching. Fabricated DCPBH-DFB LD operates in single longitudinal mode with side-mode suppression of more than 35dB and the lasing wavelength of 1.547㎛ at room temperature and 5mW, and the lasing threshold current and the slope efficiency were 15.6mA and 0.15mW/mA, respectively. The characteristic temperature of threshold current(To) and the temperature dependence of the lasing wavelength were obtained 57.3K and 1.0Å/℃ from the DFB laser between 20℃ and 70℃, respectively.

평판램프의 주파수 특성

김명녕,권순석,이정환 大田産業大學校 2002 한밭대학교 논문집 Vol.19 No.-

In this paper, the frequency characteristics of flat fluorescent lamp(FFL) using ultra-violet generated from gas discharge are studied. The lamp is constructed of a simple structure with insulator layer, phosphor layer, and gas gap(1.1 [㎜]). The firing voltage is decreased as the frequency is increased. It is considered that this tendency is resulted from the space charge effect due to Xe and Ar positive ions trapped in gas gap. Decreasing of uniform voltage at the region of higher drive frequency is due to the remaining space charges which are produced by preceding period. Increasing the drive frequency, the luminance is also increased because ultraviolet generated in gas gap is increased. The luminance in FFL using Xe of discharge gas is shown 2700[cd/㎡] at the operation point of 700[V_rms], 80[㎑]. Uniformity is obtained 96[%] over the entire lamp surface. Hence, the maximum luminous efficiency is obtained 5[㏐/W].

초등학교 자연과 교육과정안의 작성과 그 연구

임정환,김병업,김명환,김재경 대구교육대학교 1970 論文集 Vol.6 No.-

This researching group of four members of us organized this test plan on the ground of following standpoints: 1. Science education should be designed for the general outline of natural science to be taught till the period of compulsory education is expired. 2. Natural science consists of two elements; one is the scientific method as a way of understanding nature and the other is the system of concept which is got as the result. 3. Science education should be designed, after increasing the belief in sciecne, for the effects of learning to be transformed into the sources of the judgements and behaviours. In this test plan, we definitely represented the above three standpoints as followings: 1. These system of concept of natural science can be condensed into several basic general concepts. These basic concepts become the essence of curriculum plan. Field of Non-living Matters Field of Living Thing 1. Matter 1. Feed 2. Force and Motion 2. Growth 3. Energy 3. Reproduction 4. Time and Space 4. Interaction to Environments 2. The general conepts are incessantly extended and deepened through the process while the scientific methods are applied. The scientific methods which are applied here are these: 1) Observation 2) Classification 3) Experiment 4) Modeling 3. The contents of the thextbook were chosen all over the fields of the natural science but the various contents should be taught wholly and connectively all over the nature. We settled the syllabus between the first grade and the sixth of elementary school on the ground of the above-mentioned basic standpoints and principles.(Refer attached table.) When this test plan is organized successfully, a desirable character who can flexibly adapt to the rapidly changing society and has extentive possibilities will be expected through science education.

굽힘변형된 선박용 프로펠러의 보수방법의 개발

임명환,정의정,윤한용 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

Bending and fracture damages occur on marine propellers in services. A method by heating and hammering is generally used to repair the propellers. However, it is inevitable that the strength is degraded by using the method. A new method to increase the fatigue strength of propeller materials was suggested in the previous study. In this study, we adapted the method to repair bended propeller materials and proved its usefulness by the static and fatigue testing.

규칙기반 시스템과 데이터베이스 관리 시스템의 통합 기법에 관한 연구

류명춘,정영석,오주환 경운대학교 산업기술연구소 2001 産業技術硏究論文誌 Vol.3 No.2(B)

It is useful of the integration of rule systems into DBMS. Because rule-based system supports a eminent inference and analysis power and relational DBMS manages efficiently large data supporting consistency and independency. In this paper, we compares and analyzes the three approach for the integration of rule system into DBMS. Also we design inference system for rule-based database system.

HgCdTe 제작 다이오드 어레이의 열처리에 따른 전기적 특성

이정환,권순석,김명녕,이상래,황문구 大田産業大學校 2001 한밭대학교 논문집 Vol.18 No.-

This paper is investigated on the study of uniformity improvement and electrical characteristics for the 1×128 diode array used Hg^0.7Cd^0.3Te. The electrical characteristics were measured for the device manufactured by several different annealing processes and temperatures being discrepant from existing method of annealing processes and temperatures. The results of uniformity were improved from 60∼80[%], the rate of existing uniformity, to 99[%]. The results obtained from analyzing and examining the characteristics of current-voltage(I-V) and capacitance-voltage(C-V) are following. First, the reverse current show 6[㎁] or so. It is seemed to be resulted from the decrease of direct tunneling and trap tunneling of the device. Second, when the input bias voltage is zero, the maximum value of reverse resistance show 12[GΩ], and the mean value of reverse resistance show 5[GΩ]. Third, it is shown that the voltage of the maximum value of resistance is shifted 0.1[V] to the reverse direction.

單調增加荷重을 받는 平面 트러스의 複合 非線型 擧動에 關한 硏究

權寧煥,金和中,金明璇,魯德煥 경북대학교 산업기술연구소 1990 産業技術硏究誌 Vol.18 No.-

The object of this study is that develop computer program as being derive simple formula considering complex (material and geometric) nonlinear, and select the most useful truss in efficiency with the analysis Howe truss, Fink truss, Pratt truss and Warren truss. The complex nonlinear behavior is considered in this paper, so is acquired following results. 1. We developed program that could analyze complex nonlinear of plane truss. 2. In view of the results analyzied the numerical analysis example of plane truss, When Howe truss, Fink truss, Pratt truss, and Warren truss are equal to weight and span, and the same load is loaded. Among the trusses of same weight, Warren truss is the most useful in efficiency. And When height of warren truss is changed, the lower height of truss, the more useful in efficiency

정전 열 접합을 이용한 Multi-Substrate Bonding

이덕중,주병권,최우범,한정인,조경익,이광배,장진,오명환 경북대학교 센서기술연구소 1997 센서技術學術大會論文集 Vol.8 No.1

We performed silicon-to-glass bonding using silicon direct bonding followed by anodic bonding(SDAB). Initial bonding between glass and silicon was caused by the hydrophilic surfaces of silicon and glass ensemble using silicon direct bonding(SDB) method. We found that the bonded specimen using SDAB process had higher strength than one using anodic bonding process only. We performed multiple layer bonding by SDAB, which is glass- silicon -glass as sandwich structure. In the silicon wafer, the (1mm x 2mm x 500μm)-sized cavity was formed by the anisotropic etching of the silicon substrate in EPW(Ethylendiamin-Pyrocatechol-Water). And, the cavity was sealed with glass wafers by SDAB method.