수중운동체 방사소음의 로이드 미러 효과 연구

강승희,Kang, Seung-Hee 한국음향학회 2021 韓國音響學會誌 Vol.40 No.4

The measurement of the Underwater Radiated Noise (URN) for the underwater vehicle should consider both the acoustic interference due to the surface reflection and the calculation of the Closet Point of Approach (CPA). In this paper, I tried to analyze the underwater vehicle's URN using the Lloyd's mirror effect. First, the theoretical Lloyd's mirror pattern was compared with the sea trial result, and the sea trial results corresponded well with the theoretical predicted pattern. And then the CPA distance could be estimated by the Lloyd's mirror pattern. As a results, acoustic source level shows the spectral fluctuation due to the acoustic interference of the Lloyd's mirror effect.

회전타원체 보빈 형상의 거동에 관한 연구

강승희,안성호,임완권,김혜웅,Kang, Seung-Hee,Ahn, Sung-Ho,Rim, One-Kwon,Kim, Hye-Ung 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.5

The initial trajectory of a spheroid configuration bobbin for precision guidance has been investigated by analyzing its aerodynamic load and six-degree-of-freedom motion. The effects of changes in the spheroidal head configuration, flow angle and lateral center-of-gravity offset are numerically studied using the commercial software "FLUENT". A wind tunnel test is also conducted to validate the numerical scheme and to examine effect of the Reynolds number on the flow around the bobbin. It is shown that the size of the separation bubble formed on the surface decreases significantly when the Reynolds number is varied between 110,000 and 140,000. At a zero flow angle, an oblate spheroidal head shows relatively moderate rotation while a prolate spheroidal head shows rapid rotation. The bobbin with a spherical head shape has little effect on the flow direction; however, the oblate bobbin is sensitive to the flow angle. The roll motion of the bobbin is greatly influenced by the lateral center-of-gravity offset and maximum dispersion is observed at half of the radius.

측풍 조건을 고려한 로터블레이드 형상의 공력성능에 대한 실험적 연구

강승희,유기완,Kang, Seung-Hee,Ryu, Ki-Wahn 한국항공운항학회 2017 한국항공운항학회지 Vol.25 No.2

In the present study, a wind tunnel test for a rotor-blade configuration was conducted to investigate a basic aerodynamic performance and a effect of the cross wind. The diameter of the configuration was 1.46 m and the test was carried out for both a clean and a tripped configurations. The boundary layer for the trip configuration was simulated by zig-zag tape and the test performed on constant-velocity and constant-rotational modes. It was shown that the test result for the tripped configuration reduces the maximum power coefficient by 9.4% ~ 12.1% compared to the clean one. Within $5^{\circ}$ of the flow angle, there is no significant loss of power, however, the coefficient is reduced by 5.3% ~ 36.7% in the range of $10^{\circ}{\sim}30^{\circ}$.

성인 남자의 의복구매동기와 자아개념과의 관계 연구

강승희,이명희 ( Seung Hee Kang,Myoung Hee Lee ) 대한가정학회 1993 Family and Environment Research Vol.31 No.1

진도관리 자동화를 위한 자료수집기술(DAT) 선정 방법

강승희,정영수,Kang, Seung-Hee,Jung, Young-Soo 한국건설관리학회 2012 한국건설관리학회 논문집 Vol.13 No.1

건설 프로젝트의 성과 측정 및 관리에 있어 진도관리는 기본적이며 핵심적인 업무기능이다. 오랜 기간 동안 다양한 진도 관리 기법이 연구 개발되고 있음에도 불구하고, 자료수집을 위한 과도한 업무부담은 체계화된 진도관리의 장애요소로 지적되어 왔다. 최근 자료수집기술(Data Acquisition Technology, DAT)의 발전은 자동화된 진도관리의 기회를 제공하고 하고 있다. 그럼에도 불구하고 지금까지의 DAT 연구는 특정 공종 또는 특정 기술에 집중하고 있어, 건설사업 전체의 진도관리 자동화에 대한 연구는 이루어지지 않았다. 이러한 관점에서, 본 연구는 건설사업 공종별 최적의 DAT를 선정하는 방법론을 제안하였다. DAT 선정방법은 각 공종별 진도측정의 방법, 대상, 범위, 기술 등의 유형을 분류하여, 이를 DAT 특성별로 최적치를 도출하는 알고리즘으로 구성된다. 제안된 방법론의 검증을 위하여 사례 프로젝트를 이용한 기계적 분석을 실시하고 또한 실무자 평가를 수행한 결과, 대부분 공종에서 동일한 결과를 얻었다. 또한 사례현장 평가결과 중의 하나로서, 노무자의 층별 출입정보를 RFID를 활용하여 측정하는 것이 가장 효율적이며 가장 많은 공종에 적용이 가능한 것으로 나타났다. Progress measurement provides project participants with valuable information in terms of 'current status', 'corrective countermeasure', and 'forecast of future risks'. However, the managerial effort (or workload) required to acquire and maintain detailed progress data has been the major barrier to practical implementation. Even though recent efforts in utilizing data acquisition technologies (DATs) have actively attempted to automate the progress measurement process, previous DAT research has only been focused on limited construction tasks or selected technologies. This paper proposes a DAT selection algorithm that automatically assign an appropriate DAT for every commodity item for an entire constriction project. Five different criteria were identified and developed in order to comprehend specific requirements for automating the progress measurement of each commodity group. A case-study and also a survey from practitioners were conducted in order to validate the proposed methodology.

CdSe/ZnS 나노결정 양자점 Pyrolysis 제조와 발광다이오드 소자로의 응용

강승희,키란쿠마르,손기철,허훈회,김경현,허철,김의태,Kang, Seung-Hee,Kumar, Kiran,Son, Kee-Chul,Huh, Hoon-Hoe,Kim, Kyung-Hyun,Huh, Chul,Kim, Eui-Tae 한국재료학회 2008 한국재료학회지 Vol.18 No.7

We report on the light-emitting diode (LED) characteristics of core-shell CdSe/ZnS nanocrystal quantum dots (QDs) embedded in $TiO_2$thin films on a Si substrate. A simple p-n junction could be formed when nanocrystal QDs on a p-type Si substrate were embedded in ${\sim}5\;nm$ thick $TiO_2$ thin film, which is inherently an n-type semiconductor. The $TiO_2$ thin film was deposited over QDs at $200^{\circ}C$ using plasma-enhanced metallorganic chemical vapor deposition. The LED structure of $TiO_2$/QDs/Si showed typical p-n diode currentvoltage and electroluminescence characteristics. The colloidal core-shell CdSe/ZnS QDs were synthesized via pyrolysis in the range of $220-280^{\circ}C$. Pyrolysis conditions were optimized through systematic studies as functions of synthesis temperature, reaction time, and surfactant amount.

B축 회전 기능을 갖춘 복합공구대 구조물의 정/동적 안정성에 관한 연구

강승희(Seung-Hee Kang),김재실(Chae-Sil Kim) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.1

Techniques of tool posts are developing such that variable machining is possible using only one machine for the complication of a product"s shape and to reducethe machining time. In order to develop a mill turret with a variable machining function with the mounting of mill turret units on a B-axis tilting table, we determine the static/dynamic stability ofthe structure of the mill turret. To this end, a static structural analysis and a modal analysis wereconducted. From the results of the static structural analysis, the maximum stress was found to be less than the allowable stress. By the comparing the results of the modal analysis ofthe excitation frequencies ofthe mill turret, there wereno resonance regions found. Therefore, the mill turret with theB-axis tilting facility is shown to have good structural integrity.

예비교사의 비판적 사고력 향상을 위한 프로그램 개발 및 효과검증

강승희(Seung-Hee KANG),김대현(Dae-Hyun KIM) 한국수산해양교육학회 2006 水産海洋敎育硏究 Vol.18 No.2

The purpose of this study is to develop and to test the program for the improvement of preservice teachers' critical thinking ability. The main research problems to achieve the purpose of research are as follows; first, is the program for the improvement of preservice teachers' critical thinking ability effective to improve the critical thinking skills of preservice teachers? Second, is the program for the improvement of preservice teachers' critical thinking ability effective to improve the critical thinking dispositions of preservice teachers? To evaluate the effect of the program, 30(15; experimental group: 15; control group) sophomores were selected in Pusan. The conclusions of this research are as follows; first, there is a significant difference between experimental group and control group for critical thinking skills test. Second, there is no significant difference between experimental group and control group for critical thinking dispositions test.

공학계열 대학생의 성차: 학업 성취도, 일반적 자기효능감, 공학 자기효능감을 중심으로

강승희(Seung Hee Kang) 한국공학교육학회 2010 공학교육연구 Vol.13 No.4

본 연구는 공학계열 대학생의 성차가 학업성취도, 일반적 자기효능감, 공학 자기효능감 변인 중 어느 변인에서 나타나는 지를 알아보는 것을 목적으로 하였다. 본 연구에는 공학계열 3학년에 재학중인 남학생 284명, 여학생 103명이 참여하였다. 학업 성취도는 연구대상 학생의 전 학기 학점을 자기보고식으로 취합하였으며, 일반적 자기효능감과 공학 자기효능감은 검사를 실시하였다. 학업성취도에 대한 차이 검증결과 공학계열 여학생과 남학생의 학업성취도에는 유의한 차이가 나타나지 않았다. 그러나 일반적 자기효능감에 대한 다변량 분석 결과, 유의한 차이가 나타났으며, 단변량 분석에서도 자신감, 자기조절 효능감, 과제난이도 선호 모두에서 남녀간에 유의한 차이가 나타났으며, 남학생의 자기효능감이 높은 것으로 나타났다. 또한 공학 자기효 능감에 대한 다변량 분석결과에서 남녀간에 유의한 차이가 나타났으며, 단변량 분석결과 전공영역 효능감, 직무효능감, 팀활동 효능감, 창의성 효능감 모두에서 남녀간에 유의한 차이가 나타났다. 이러한 결과를 통해 공학계열 대학생의 성차는 학업성취도가 아닌 효능감 영역에서 나타나고 있음을 알 수 있었다. The purpose of this study was to investigate whether there were difference between gender of engineering students in terms of academic achievement, self-efficacy and engineering self-efficacy. A total of 387 engineering students (male=284, female=103) completed the self-efficacy and engineering self-efficacy test. And students self-reported their grade point average(GPA) in their former semester. The results of t-test with gender about academic achievement indicated that there were not differences in academic achievement between gender. The results of MANOVA with grades indicated that there were differences in self-efficacy and engineering self-efficacy between gender. Male students scored significantly higher than female students in self-efficacy, and engineering self-efficacy.

論文(논문) : 풍력터빈 성능시험을 위한 저속풍동 개념연구

강승희 ( Seung Hee Kang ) 한국항공운항학회 2011 한국항공운항학회지 Vol.19 No.4

Conceptual study of an open-circuit type low-speed wind tunnel for performance test of wind turbine blade and airfoil is conducted. The tunnel is constituted of a settling chamber, a contraction, closed test section, a diffuser, two corners, a cross leg and a fan and motor. For the performance test, the closed test section width of 1.8 m, height of 1.8 m and length of 5.25 m is selected. The contraction ratio is 9 to 1 and maximum speed in the test section is 67 m/sec. Input power in the tunnel is about 238 kW and its energy ratio is 3.6. The wind tunnel designed in present study will be an effective tool in research and development of wind turbine and airfoil.