• 대한물리치료과학회지
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• 제19권1호
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• pp.47-54
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• 2012

Purpose : This study is to know the effect on muscle activity when people use mouse aid or not in computer working environment. Method : 11 people of both sex in their twentieth were tested. As a independent variable, the condition without mouse aid and the condition with movable mouse aid were selected, and as a dependent variable, MVC(%) on four muscles and inconvenience degree(RPE scale) on three body part(wrist, forearm, shoulder) were measured. Result : Analyzing the research, MVC(%) of extensor muscle of finger had notably higher muscle activity than other muscles, and there wasn't notable difference in muscle activity before and after using mouse aid. In case of using mouse aid, we tested by giving RPE questionnaire which segmentalized mental fatigue degree into hand, forearm, and shoulder, and resultingly, there wasn't notable differences perspectively. However, people felt less tiredness subjectively after they use the mouse aid. Conclusion : The usage of mouse aid seems to give comfort to computer users.

• 패션비즈니스
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• 제12권6호
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• pp.81-92
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• 2008

The purpose of this study is to develop the applied brassiere pattern of women which are fitting for 75A. The constructing of this experimental brassiere were lower cup, upper cup, front panel and U-wing as well as a full cup embcing the entire breasts. Basing on the bra model from domestic experiment results, development of an applied design, round side type pattern, has been suggested. Thus, suggesting the round variation design bra, which is an applied design based on the basic model based on the breast volume. Based on the sizes that are in reference to Size Korea (2004) and related previous researches, the basic model that has been experimented with 11.4% polyurethane and 88.6% Nylon as the materials, has been selected as the model of research. This takes 75A, the size of which is set according to the underbust circumference and the breasts circumference, as the basic model. It is an application in terms of design, and there is no change to the cup volume or size because it has been moved only from the cutting line. The applied design changes the right side of the lower cup into an easily-movable form and attaches it to the upper cup, and the lower cup takes the right part of the upper cup to form a cup shape of round variation design. It also changes basic straight form of the wings, and alters them into U-shape.

• 대한조선학회논문집
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• 제41권5호
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• pp.28-33
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• 2004

Generally Horn-type rudders have been used for single propeller and single rudder system. The reason is that the rudder torques of Horn-type rudder are smaller than those of Spade rudder with same lift force. But it is found that the rudder cavitation occurs on a Horn-type rudder of fast container ship. In this paper the comparison results of Horn-type and Spade rudders are described. HPMM tests are carried out to compare the effects of two rudder types on the maneuverability of a ship. It is shown that the maneuvering performance of a ship equipped with Horn-type rudder is better than that equipped with Spade rudder by comparing the test results and maneuvering coefficients at scantling condition. The reason is that the movable part area of Horn-type rudder is about 14％ larger than that of Spade rudder with same total area. And the rudder torque of Spade rudder is greater than that of Horn rudder. At ballast condition, however, the effect of rudder type is negligible.

• Transactions on Electrical and Electronic Materials
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• 제9권3호
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• pp.128-133
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• 2008

In this paper, in order to analyze property of frequency response in microphone using optical sensor, acousto-optic sensor system has been implemented. The capacitance microphone and fiber-optic transmission path type fiber-optic microphone (FOM) have weaknesses in directivity, size, weight, and price. However suggested optical microphone can be constituted by cheap devices, so it has many benefits like small size, light weight, high directivity, etc. Head part of optical microphone which is suggested in this paper is movable back and forth by sound pressure with the attached reflection plate. Operating point has also been determined by measuring the response characteristics. The choosing the point, which has maximum linearity and sensitivity has changing the distance between optical head and vibrating plate. We measured the output of the O/E transformed signal of the optical microphone while frequency of sound signal is changed using sound measurement /analysis program, "Smaart Live" and "USBPre", which are based on PC, and compared the result from an existing capacitance microphone. The measured optical microphone showed almost similar output characteristics as those of the compared condenser microphone, and its bandwidth performance was about 4 kHz at up to 3 dB.

• 대한조선학회논문집
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• 제45권3호
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• pp.238-246
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• 2008

In the present study, the influences on the gap cavitaiton of the semi-spade rudder are investigated experimentally in the condition with propeller and hull wakes. To reduce the scale effect in the given experimental conditions, 1/28.5-scale-down models of propeller and rudder are manufactured. We have the propeller rotate ahead of the rudder, inducing the three dimensional effects originated from the propeller action. Experimental methods are composed of the cavitation observation using high speed camera, PIV (particle image velocimetry) measurements to visualize the cavitaition and flows around the gap. The propeller slipstream affects both of the gap flows and cavitation of the rudder.

• 한국통신학회논문지
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• 제31권7B호
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• pp.595-601
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• 2006

이 연구는 유비쿼터스 컴퓨팅 환경에서 절대 위치 좌표를 제공할 수 있는 초음파 위치인식 시스템에 관한 것이다. 무선(RF: Radio Frequency) 신호에 의해 동기화된 다수의 고정된 발신기가 순차적으로 초음파를 발신하며, 초음파 신호들을 수신한 수신기에서 TOF를 파악하여 이를 거리로 환산한 다음 위치정보를 계산한다. 초음파의 전파시간(TOF: Time of Flight)은 주기인식 방법을 통해 파악한다. 또한 유비쿼터스 컴퓨팅을 위한 인식 영역의 확장을 위해 셀 매칭 기법과 부호화된 초음파 기법을 제안한다. 초음파 위치인식 시스템인 U-SAT을 사용하여 주기인식 기법의 유용성을 입증하기 위하여 다양한 거리에서 실험을 수행하였다. 또한 셀 매칭 기법에 의한 영역 확장에서도 위치 측정의 정확도를 검증하였으며 부호화된 초음파 기법의 분석으로 그 유용성도 입증하였다. 그 결과로 인해 저가격, 높은 갱신율, 그리고 상대적으로 뛰어난 정밀도의 입장에서 GPS가 적용될 수 없는 환경에서의 유비쿼터스 컴퓨팅의 위치인식 시스템으로서의 가능성을 입증하였다.

• 한국주거학회논문집
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• 제20권3호
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• pp.37-45
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• 2009

For the young period, privacy is a crucial factor in establishing one's own identities, values and relationships. The capacity of residential environment to protect individual's privacy takes considerable part in influencing psychological and physiological development of adolescents. This study analyzed adolescents residential values and the elements of spatial plans for the passage and outdoor in Apartment Design Competition of Suwon A district in 2008. One hundred and ten middle and high school students living in Metropolitan area were selected and questionnaire was conducted during February 7 to February 15 in 2009. The data was analyzed by SPSS 11.0 program using one-way ANOVA and crosstab. The study results were summarized as follows; First, the adolescents valued 'safety' the most, regardless of their age and gender and the safety of adolescents commuting should be considered. Second, protecting their own private territories was next important element among other elements. Privacy can be protected by using movable walls, changing the doorway, dividing parents' and adolescents independent territory. Third, in terms of convenience, choosing location of children's room and walking way should be considered. Forth, from the survey, demand for indoors leisure activity was highly valued and required for aesthetic point of view. Considering the sculptures and facilities must satisfy the aesthetics and practicality. Fifth, in terms of social needs, 61.6% of people answered positively to the community facilities for social relationship. Residential environment affects enormous part of adolescents emotional and academic development. Therefore, designing residential areas for adolescents friendly should reflect the demands for safety, territory, convenience, aesthetic and social life.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권11호
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• pp.601-611
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• 2002

As resent trends in structural construction have been to build taller and larger structures than any time in the past, they have had high flexibility and low damping that can cause large vibration response under severe environmental loading such as earthquakes, winds, and mechanical excitations. The damper with mass and sqring is one aproach to safeguarding the structure against excessive vibrations. In this paper, a large capacity hybrid-type linear motor damper(LMD) was designed and fabricated for the application to the vibration control of a large building structure model. It has been designed to be able to move the damper mass, 1,500 kg up to ${\pm}250mm$ strokes at the first mode natural frequency of the building structure model, ${\pm}0.51Hz$. Linear motor is consisted of the fixed coil and the movable NdFeB permanent magnets field part. The PM field part composed magnet modules and iron yoke, is the damper mass itself, 1500kg. LMD therefore has a simplified structure and requires a few elements in the driving system, being compared with a rotary motor damper and a hydraulic damper. However, the manufacture of large PM linear actuator is difficult because of the limit of PM size and the attraction and repulsion at the assembly of PM. Therefore, large damper system is manufactured and tested for dynamic characteristics and frequency response.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.123-128
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• 2012

작동 시퀀스에 따른 핀틀 노즐의 성능 특성을 비교하였다. 비정상상태 이동격자 수치해석 기법을 이용하여 시간에 따른 핀틀의 위치 변화를 고려하였으며, 다양한 핀틀 형상과 작동 시퀀스에 따른 성능 응답지연 및 민감도 분석을 수행하였다. 연소실 내부의 압력 상승률과 압력진동이 성능에 미치는 영향을 관찰하기 위하여, 노즐 목에 핀틀이 머무르는 시간이 다른 세 가지의 작동 시퀀스를 고려하였다. 핀틀이 노즐 목에 머무르지 않는 경우(case 1), 0.5초 머무를 경우(case 2) 그리고 노즐 목 위치에 계속 정지해 있을 경우(case 3)에 대해 비교하였고, 이를 통해 작동 시퀀스 및 핀틀 형상에 따른 동특성 연구를 수행하여 추력 특성 변화를 도출하였다.

• Design & Manufacturing
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• 제16권4호
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• pp.67-74
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• 2022

Injection molding is a cyclic process comprising of cooling phase as the largest part of this cycle. Providing efficient cooling in lesser cycle times is of significant importance in the molding industry. Recently, lots of researches have been done for rapid cooling of a hot-spot area using CO2 in injection molding. The CO2 flows under high pressure through small, flexible capillary tubes to the point of use, where it expands to create a snow and gas mixture at a temperature of -79℃. The gaseous CO2 removes heat from the mold and releases it into the atmosphere. In this paper, a CO2 cooling module was applied to an injection mold in order to cool a large area cavity uniformly and quickly, and the cooling performance of the injection mold was investigated. The product was a high-curvature molded part with a molding area of 300x100mm. Heat cartridges were installed in a stationary mold, and CO2 cooling module was inserted inside a movable mold. Through structural analysis, it was confirmed that the maximum deformation of mold with CO2 cooling module was 0.09mm. A CO2 feed system with a heat exchanger was used for cooling experiments. The CO2 was injected into the holes on both sides of the supply pipe of the cooling module and discharged through hexagon blocks to cool the mold. It took 5.8 seconds to cool the mold from an average temperature of 140℃ to 70℃. Through the experiment using CO2 cooling module, it was found that a cooling rate of up to 12.98℃/s and an average of 10.18℃/s could be achieved.