• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.191-191
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• 2009

In this paper, we have confirmed the temperature of LED chip and McPCB with thermal simulation program which is CFDedign V10 for analysis the thermal flow of HP LED package. we have known that the heat from LED chip is transferred through heat slug to copper layer of McPCB. the temperature of LED chip shows 85.11 [$^{\circ}C$], which shows the temperature gap of 7.52 [$^{\circ}C$] against McPCB. the gap of temperature affect reliability of the wire bonding and die attachment. therefore, copper layer of heat slug on the McPCB should designed with the largest dimension.

• 대한전자공학회논문지SP
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• 제48권2호
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• pp.102-108
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• 2011

기존의 선박 내 조명 제어 시스템은 구축의 복잡성, 높은 설치 비용 및 유지 관리 비용 등의 문제점이 있다. 본 논문에서는 디지털 선박 환경에서 저비용, 고효율의 조명제어 시스템을 설계하였다. 사용자의 생체 정보(맥박, 이완기 혈압, 수축기 혈압, 혈당)를 무선 센서들을 통하여 획득한 후 감성을 인식하여 LED 조명을 제어하는 시스템으로서, 맥박 센서, 혈압 센서, 혈당 센서 등의 입력치를 받아 데이터베이스에 저장한 후 역전파 신경망 알고리즘을 이용하여 감성을 분류한다. 3,000개의 데이터 집합을 사용하여 역전파 신경망을 실험한 결과 약 88.7%의 정확도를 가졌다. 분류된 감성은 HP(Hewlett-Packard)의 'The Meaning of Color'에서 정해 놓은 20개의 컬러 감성 모델과 비교하여 가장 적절한 출력치를 찾아 적색, 녹색, 청색 LED Lamp에 전류 또는 주파수를 조절하는 방법으로 LED Lamp의 밝기 또는 광색을 조절함으로써 소모 전력을 약 20%로 절감하였다.

• 전기학회논문지P
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• 제58권2호
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• pp.142-147
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• 2009

Conventional HP(high pressure) sodium or Metal-halide lamps have a life span of around one year requiring at least annual replacement and maintenance. High Power LED lights require no regular maintenance further increasing savings on replacement bulbs, access equipment and labour costs. New installations benefit from a substantial reduction in the cost of expensive heavy duty cable required for sodium lighting. Especially, LED light can achieve variable color temperature, high functional performance in the field of street light. There are two main method to achieve variable color temperature function of the street light. one method is using RGB multi-chip LED, the other is using Orange-White LED method. In this paper, it was compare RGB Multi-chip LED with white-orange LED for there characteristics performance.

• Restorative Dentistry and Endodontics
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• 제47권1호
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• pp.7.1-7.14
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• 2022

Objectives: This study evaluated the bleaching efficacy of different in-office protocols associated with violet light emitting diode (V-LED), and measured the pulpal temperature rise caused by V-LED with or without gel application. Materials and Methods: Bovine incisors were distributed in 4 groups (n = 10): VL - V-LED; HP - 35% hydrogen peroxide (control); HYB - hybrid protocol, V-LED applied without gel for 10 irradiation cycles followed by V-LED applied with gel for another 10 irradiation cycles; and HPVL - gel and V-LED applied for 20 irradiation cycles. Three bleaching sessions were performed with 7-day intervals. Bleaching efficacy was evaluated with ΔE_ab^*, ΔE₀₀ and ΔWI_D. Data were recorded at baseline, 7, 14, 21 and 70 days. For pulpal temperature rise, thermocouples were placed inside the pulp chamber of human incisors. To determine intrapulpal temperature, the teeth were irradiated with V-LED with or without application of bleaching gel. Color difference data were analyzed by 2-way repeated measures ANOVA and Tukey's test. Pulpal temperature was analyzed by t-test (α = 5%). Results: VL exhibited lower color (ΔE_ab^* and ΔE₀₀) and whiteness changes (ΔWI_D) than the other groups. HPVL presented higher color change values than HYB. HYB and HPVL showed not different ΔWI_D values; and HP showed the highest whiteness changes at all times. There were significant differences comparing ΔT with gel (8.9℃) and without gel application (7.2℃). Conclusions: HPLV was more efficient than HYB. The 2 protocols with VL showed similar results to control. Gel application combined with VL promoted higher pulpal temperature than to the no gel group.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.297-298
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• 2009

대부분의 반도체 소자의 고장 원인은 85%정도가 열로 인한 것이며, 고출력 LED는 인가된 에너지의 20%정도의 광으로 출력되며 나머지 80%가 열로 전환된다. 본 논문에서는 PMS-50과 KEITHLEY 2430을 이용하여 PCB 구조와 Via hole 구성에 따른 LED 패키지의 열적 광학적 특성을 분석하였다. 0.6mm의 Via hole을 가진 FR4 PCB의 열특성이 가장 우수하였으며, Via hole 0.6mm FR4 PCB의 경우 McPCB에 상응하는 광출력 특성을 보였다.

• 한국식생활문화학회지
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• 제24권1호
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• pp.69-76
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• 2009

This study was conducted to determine the optimal cooking conditions for brown rice using an electric pressure rice cooker. The effects of steeping conditions and cooking pressure on the hydration, gelatinization, texture and palatable properties of cooked brown rice were evaluated. Based on water uptake and DSC data, the optimal steeping time and temperature for brown rice were determined to be 25 minutes and ${\sim}60^{\circ}C$, respectively. The cooking conditions for brown rice were then divided into the following 6 categories: steeping at $25^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (25P) or 1.9 (25HP), steeping at $57^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (57P) or 1.9 (57HP), steeping at $85^{\circ}C$ for 15 minutes and cooking at an atmospheric pressure of 1.7 (85P) or 1.9 (85HP). The susceptibility of cooked brown rice starch to degradation into maltose by ${\alpha}$-amylase, which is related to the degree of gelatinization and in vitro digestibility, were then determined. The amount of maltose produced by cooked brown rice samples was highest in the 57HP group, followed by the 57P and 85HP groups. Storing cooked brown rice at $73^{\circ}C$ for 24 hours resulted in significantly higher amounts of starch being degraded into maltose in the 57P, 57HP and 85HP groups than in the other groups. Textural analysis demonstrated that the 57P, 57HP and 85HP groups had significantly lower gumminess and chewiness values when compared to the other groups, and that 57HP received had the lowest hardness of all treatments. These results were confirmed by the results of the sensory evaluations. Furthermore, the 57P and 57HP groups were found to have a higher glossiness, stickiness aroma and taste score than the other groups. These findings were taken to indicate that steeping conditions and pressure exerted a positive synergistic effect on the cooking quality of brown rice. The texture analyzer also revealed that storing the cooked rice at $73^{\circ}C$ for 24 hours only led to significantly lower scores in gumminess, hardness and chewiness in the 57P and 57HP groups, which indicates that these groups underwent a lesser degree of retrogradation than other groups. Taken together, the results of the present study demonstrate that steeping brown rice at $57^{\circ}C$ for 25 minutes and a higher cooking pressure improved the palatability and in vitro digestibility of brown rice significantly.

• 한국자동차공학회논문집
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• 제22권7호
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• pp.90-97
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• 2014

The effects of high pressure and low pressure exhaust gas recirculation (HP/LP EGR) portion on diesel engine combustion and emissions characteristics were investigated in a 2.2 L passenger-car diesel engine. The po3rtion of HP/LP EGR was varied from 0 to 1 while fixing the mass flow rate of fresh air. The intake manifold temperature was lowered with the increasing of the portion of LP EGR, which led to the retardation of heat release by pilot injection. The lowered intake manifold temperature also resulted in low nitrogen oxide (NOx) emissions due to decreased in-cylinder temperature and prolonged ignition delay, however, the carbon monoxide (CO) emission showed opposite trend to NOx emissions. The brake specific fuel consumption (BSFC) was decreased as the portion of LP EGR increased due to lowered exhaust manifold pressure by wider open of turbocharger vane. Consequently, the trade-off relationship between NOx and BSFC could be improved by increasing the LP EGR portion.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2004년도 제21차 정기총회 및 학술발표회
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• pp.80-90
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• 2004

본 실험은 사료내 아미노산 균형과 라이신 함량이 성장기 브로일러의 에너지 대사 중 Heat production(HP)과 질소 대사에 어떤 영향을 미치는 규명하기 위해 실시하였다. 실험1은 여러 단계의 조단백 함량과, 제1제한 아미노산으로써 일정 농도의 라이신 함량으로 만들어진 사료로 테스트하였다. 실험2에서는 이와 반대로 일정한 조단백 함량과 각기 다른 수준의 라이신을 함유한 사료들을 사용하였다. Thermoregulatory demand에 따른 영향을 최소화하기 위해 실험3은 이전 실험들(20 $^{\circ}C$)보다 높은 온도인 30 $^{\circ}C$에서 시행되었다. 에너지 및 질소 대사 실험은 컴퓨터로 제어되는 multi-chamber calorimeter system을 사용하여 조사하였으며 사료의 단백질 및 라이신 조성에 따른 닭의 HP를 측정하였다. 또한 이를 통해 나온 결과들은 에너지 대사 컴퓨터 시뮬레이션 모델을 통한 예측치와 비교하였다. 다양한 단백질 함량과 일정한 라이신 함량의 사료를 통한 실험에서 단백질 함량이 증가함에 따라 질소 섭취에서는 75 %의 증가가 나타났다. 이것은 질소 배출에 있어서 150 %의 증가를 가져왔으나 이에 따른 HP에 유의적인 차이는 보이지 않았다. 다양한 라이신 함량과 일정한 단백질 함량의 사료를 사용한 실험2에서는 최저 라이신과 최고 라이신 처리구 간에 3배의 증체량의 차이를 보여주었다. HP에 있어서는 라이신 증가에 따라 유의적으로 증가하는 경향을 보였으나 체중 보정치에 있어서는 유의차가 사라졌다. 실험1과 실험2, 두 실험의 시뮬레이션을 통한 HP 계산치에 있어서도 처리구들 간에 차이를 보이지 않았다. 30 $^{\circ}C$에서 실시된 실험3에서는 실험2와 동일하게 라이신 함량 증가에 따라 HP가 유의적으로 증가하였으나 그 경향은 이전 실험보다 크게 나타났다. 결과를 종합 할 때, 총 HP의 발생은 사료의 단백질 함량보다는 제한 아미노산 농도와 더욱 관련이 깊으며, 아미노산 불균형에 따른 질소 배출로 인해 발생하는 energy cost가 차지하는 비율은 높지 않은 것으로 사료된다. 또한 질소 축적율에서 볼 때, 사료내 아미노산 균형이 체내 질소 이용효율과 밀접한 관련이 있음을 확인하였다.

• Restorative Dentistry and Endodontics
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• 제44권1호
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• pp.6.1-6.11
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• 2019

Objectives: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. Materials and Methods: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. Results: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. Conclusions: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.

• Clinical and Experimental Reproductive Medicine
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• 제49권2호
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• pp.135-141
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• 2022

Objective: This study investigated the impact of two stimulation protocols using highly purified human menopausal gonadotropin (HP-hMG) on the endocrine profile, follicular fluid soluble Fas levels, and outcomes of intracytoplasmic sperm injection (ICSI) cycles. Methods: This prospective clinical trial included 100 normal-responder women undergoing ovarian stimulation for ICSI; 55 patients received concomitant follicle-stimulating hormone (FSH) plus HP-hMG from the start of stimulation, while 45 patients received FSH followed by HP-hMG during mid/late follicular stimulation. The primary outcome was the number of top-quality embryos. The secondary outcomes were the number and percentage of metaphase II (MII) oocytes and the clinical pregnancy rate. Results: The number of MII oocytes was significantly higher in the concomitant protocol (median, 13.0; interquartile range [IQR], 8.5-18.0 vs. 9.0 [8.0-13.0] in the consecutive protocol; p=0.009); however, the percentage of MII oocytes and the fertilization rate were significantly higher in the consecutive protocol (median, 90.91; IQR, 80.0-100.0 vs. 83.33 [75.0-93.8]; p=0.034 and median, 86.67; IQR, 76.9-100.0 vs. 77.78 [66.7-89.9]; p=0.028, respectively). No significant between-group differences were found in top-quality embryos (p=0.693) or the clinical pregnancy rate (65.9% vs. 61.8% in the consecutive vs. concomitant protocol, respectively). The median follicular fluid soluble Fas antigen level was significantly higher in the concomitant protocol (9,731.0 pg/mL; IQR, 6,004.5-10,807.6 vs. 6,350.2 pg/mL; IQR, 4,382.4-9,418.4; p=0.021). Conclusion: Personalized controlled ovarian stimulation using HP-hMG during the late follicular phase led to a significantly lower response, but did not affect the quality of ICSI.