• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.209-216
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• 2019

The purpose of this study was to suggest the optimum ambient illumination level for proper visualization in image inspection and reading on CRT and LCD monitors used for ultrasound and reading. The evaluators were divided into 4 groups: 20 (Ultra-sonographer: 20 groups (4 groups: ultra-sonographer, 1-5 years, 5 ultra-sonographers, 6 to 10 years, 5 ultra-sonographers, 11 to 15 years, The subjects were 32 questions. The evaluation method was image evaluation of ultrasonic soft copy images for 30 seconds per 10, 25, 100Lux ambient illumination. The evaluation results were evaluated as 6 points (Normal = Definitely no lesion), 2 points = possibly not a lesion, 3 points = probably not a lesion, 4 points = possibly a lesion, 5 points = probably a lesion, 6 points = Definitely a lesion). In this study, the results of ROC analysis according to ambient light illumination reading softcopy images used for lesion detection of all ultrasound images showed the highest sensitivity, specificity, and AUC results at 10Lux. It was found that optimal use of 10Lux for ambient light illumination would provide optimal detection of lesions in ultrasound soft copy images. Based on the future research data, it will be presented as basic data for designing ambient light brightness of ultrasound imaging laboratory and reading room.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.222-227
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• 1999

본 연구에서는 조명설계·시공과 관련하여 설계초기 단계에서 조명이 실시된 공간에 대하여 어떠한 조명 시스템이 경제적으로 유리한가를 검토하기 위한 수단으로 Worksheet를 개발하고 일반적인 사물실과 고천정 공장에서의 각종 시스템에 대한 평가를 수행하였다. 앞으로 조명설계시 광원, 등기구를 선정하는데 있어서 개발된 Worksheet를 이용하여 조도계산 및 경제성을 평가해 봄으로써 같은 비용으로 최대의 효과를 가진 조명시스템을 선택하는데 도움이 되리라 기대된다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.2
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• pp.45-53
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• 1996

평균조도 계산법 중에서 국내에서 주로 사용되는 3배광법과 ZCM의 정확도를 비교하고, 그 적용한계를 파악하였다. 비교방법은 전반확산형 조명기구와 직접식 조명기구에 대하여 3배광법과 ZCM에 의한 조명률을 계산하고, 이 값들을 이용하여 여러 상황하에서의 평균조도를 계산하였다. 몬테카를로 시뮬레이션으로 동일상황에서의 조도값을 구하고, 이 값과 3배광법과 ZCM의 조도값을 각각 비교하였다. MCS법의 정확도는 Moon위 해석적인 방법과 비교하여 입증하였다. 연구결과는 다음과 같다. 1. 방의 크기에 따른 평균조도 비교에서 전반확　형 조명기구와 직접식 조명기구의 경우 3배광법 보다 ZCM이 평균조도 오차가 적었다. 2. 광원의 수 변화에 따른 평균조도 비교에서 직접식 조명기구의 경우 3배광법은 광원의 수가 증가할수록 평균조도 오차가 감소하다가 다시 증가하였고 ZCM 은 점차적으로 감소하였다. 3. 실내면 반사율 변화에 따른 비교에서 직접식 조명기구의 경우 오차 범의가 3배광법에서 크고 ZCM에서 적게 나타냈다. 4. 방의 형태 변화에 따른 평균조도 비교에서 직접식 조명기구의 경우 방의 폭이 좁고 길이가 긴 공간에서 3배광법과 ZCM모두 오차가 크게 낱났다. 또 정방형에서 가까울수록 오차는 작아지면서 3배광법 보다 ZCM의 오차가 적었다. 그러므로 우리나라에서 혼용되고 있는 3배광법과 ZCM중에서 정확도가 높은 ZCM선택이 바람직하다.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.2
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• pp.235-242
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• 2010

An experimental investigation has been conducted to clarify roughness effects of geothermal water scale deposited onto a heating surface upon its forced convection heat transfer characteristics. Examined was a circular cylinder, on which particles of silica scale having five different sizes are uniformly distributed. The Reynolds number was varied from 13000 through 50000. Local and mean heat transfer characteristics were measured as functions of particle size and Reynolds number. Subsequently the mean fouling resistance was estimated from those results, and its characteristics are clarified. It was found that the heat transfer of cylinders greatly varies with the fouling of geothermal water scale, especially its scale height. Further, the local and average Nusselt numbers strongly depend upon the cylinder spacing and the Reynolds number.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.13-22
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• 2005

This research aimed to generate two points of daylighting application as follows: 1) providing daylight performance data with a variety of glazing materials for a large window and 2) designing and evaluating an experimental type of differentiated window. For this purpose, we compared the daylight and distribution performance of new defined type of window configuration to the conventional window counterpart with a variety of glazing materials. The comparison was made for a deep, south-facing perimeter zone with large window, without any interior obstruction. The conventional window is the base single homogeneous glass pane, where as the differentiated window uses of two different glazings; an upper daylight glazing with high visible transmission and lower view window with lower transmittal glass. The daylight performance data was translated into a ratio between outdoor illuminance and the interiors. The simulated analysis of the conventional window indicates that the interior light levels have been changed proportionally dependent on the transmittance of the applied glass. The comparison of daylight distribution analysis showed that the differentiated window has lots of photometric advantage by the optical function of upper daylight window. In particular, the contribution of higher daylight window into deep rear space must be stressed for daylighting application.

• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.337-345
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• 1992

In this research, a kinematic wave model was applied for the runoff analysis, Regulation of streamflow was estimated by the calibration of roughness coefficient as a parameter. The data analyzed were obtained from Ananomiya and Shirasaka experimental basins at Tokyo University Forest in Aichi. Estimation methods and characteristics of roughness coefficient as a evaluation method of hydrological function of forest are summarized as follows ; 1. Roughness coefficient($N_s$) indicates the resistance of hillslope to the flowing water of surface runoff. There exists an hypothesis that resistance of hillslope to flowing water increase with the growth forest and development of the $A_o$ layer. 2. Roughness coefficient($N_s$) was estimated by the parameter when the stream direct runoff was calculated by using the kinematic wave. 3. Secular change of '$N_s$' in ananomiya has a curve which has an upper limit and increases exponentially near the limit. The curve quickly increased from 1935 to 1945 when results of afforestation for erosion control were thought to be effective. On the other hand, slight increase of '$N_s$' in Shirasaka indicates that there was not such a big change in the surface of soil layer. 4. The increase of '$N_s$' was related with decrease of direct runoff and increase of base flow. It was recognized that the rate of direct runoff decreased with the improvement of forest physiognomy and the rate of base flow was increased. But absolute value of water runoff per one storm decreased in chronological order.

• Journal of the Korean GEO-environmental Society
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• v.19 no.3
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• pp.25-33
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• 2018

Piping is one of the most frequently occurring collapse type of a levee, and is often caused by roofing (backward erosion piping) at the ground-structure interface. Roofing is generally evaluated using creep ratio. However, creep ratio does not take into account the characteristics of the ground-structure interface. In this study, the roofing risk was investigated by using model test and numerical analysis considering the ground-structure interface characteristics. In the model test, it was confirmed that the piping potential decreased as the interface roughness increased, and this was applied to the numerical analysis. Existing numerical methods can not adequately simulate the particle behavior at the ground-structure interface because only the water level difference is considered. In this paper, particle behavior at the interface was investigated by performing seepage analysis and then, carrying out particle analysis technique simulating the boundary condition of the ground-structure interface. Analysis results have shown that the roofing resistance decreases as the ground-structure interface roughness decreases.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.229-234
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• 2013

The purpose of this study is to develop a lighting apparatus of the illuminance and color temperature to maximize the ability of the optimal combination of light sources that can be controlled efficiently control device. Finding people comfortable feeling for indoor lighting that can be used in a variety of color temperature illumination area by combining light sensitivity can be realized. Lighting apparatus for fluorescent lamps with different color temperature of 2000K and 8000K, and by varying the quantity of each of the fluorescent lamps, the illuminance of lighting equipment and color temperature through optical simulations were evaluated. By infrared remote control receiver, divided into 5 types of relaxation, conversation, meeting, hospitality, arts and the lighting environment you want to transfer the PC0 ~ PC4 through the parallel port on the mode selected by the user at the receiving end the DC voltage output. EEFL inverter input DC voltage and the DC input voltage, depending on the level of EEFL dimming value (illuminance and color temperature) lighting environment you want to create change while using a PIR sensor EEFL automatically turn off if people do not have was developed so that the power consumption so you can save.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.119-124
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• 2014

In this paper, we propose the active rule system applying with emotional margin for power saving control. The proposed system in this paper is a part of the system which derives smart power saving by adjusting the illuminance using active rules within compromising the user's emotion. For this, we set the specific range of standard illuminance and the lower bound of user's emotional margin of illuminance based on measurements and analysis, and use these data in design of active rules. And then, we design and implement the active rule system using mobile agent. The mobile agent in the proposed system migrates to the destination sensor nodes, acquires and transmits sensor data according to the purpose and needs through the active rules, and directly executes the actions corresponding to the optional events(changed sensor data and/or time etc.). And then, we show the potential applicability of the proposed active rule system in various active sensor network applications through the interaction with the rule base and mobile sensor network middleware system.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1696-1700
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• 2010

현재 국내에서 적용하고 있는 관내 최대유속기준 3.0m/s의 타당성을 평가하고자 SWMM 모형을 이용하여 최대유속 적용기준에 대한 우수관거 수리분석 연구를 수행하였다. 강우시 모니터링 지점의 우수유입에 따른 관내 실측결과와 검 보정을 통하여 모형을 구축하였으며, 설계빈도(10년 빈도) 홍수 유입시 관내 수리특성을 분석하였다. 관 최적 설계안 수립을 위한 관거 모델링 수행을 통해 관 경사, 조도계수 변화에 따른 관내 최대유속 민감도 분석을 수행하고 최대유속 기준 변화에 따른 최적설계안을 제시하였다. 일반적으로 우수관거 수리계산시 실무에서는 MAKESW 프로그램을 사용하고 있다. 본 연구에서는 MAKESW가 반영하지 못하는 호우시 관거내 유속, 유량변화 시계열을 SWMM 모형을 통하여 우수관거 수리분석을 수행하였다. 실제 사업지구의 경우 MAKESW를 이용하여 설계된 관내 최대유속이 3.0m/s 이하 일지라도 월류, 압력류, 배수영향을 종합적으로 고려하는 SWMM 모형의 수행결과는 일부 관거에서 설계기준 이상의 유속이 발생하는 것으로 나타났다. 설계빈도 홍수량 유입시 관 경사, 조도계수 변화에 따른 관거 내 최대유속 민감도 분석을 수행한 결과, 관 경사가 5‰ 증가할 때 관내 최대유속은 약 4~26% 증가했으며, 관경사가 완만한 경우 관 경사 증가에 따른 최고유속의 증가 민감도는 더 커졌다. 관 조도계수에 따른 최고유속 분석결과 관 조도계수가 0.005 커질 때 최고유속은 약 30% 증가하는 것으로 분석되었다. 현재 국내의 최대 유속기준을 준수하려면 규정보다 훨씬 많은 맨홀 또는 암거의 낙차공을 설치해야 하기 때문에 공사비 증대를 초래할 수 있다. 아직 기본적인 연구단계지만 본 연구결과와 보완연구를 통하여 최적의 관내 최대유속 기준조건을 우수관거 설계계획에 반영한다면 공사비 절감, 공기단축 등의 효과가 있을 것으로 판단된다.