• Journal of the Korean Applied Science and Technology
• /
• v.30 no.1
• /
• pp.127-138
• /
• 2013

This study investigated the effects of feeding the broilers that are exposed to extreme heat stress (EHS, $33{\pm}2^{\circ}C$) with extreme heat stress diet (EHSD) containing adequate amount of soy oil and other nutrients on their growth performance. 500 broiler chickens (Ross 308) were randomized into five dietary treatment groups according to a randomized block design on the day they were hatched. Each group was further divided into four repeat pens with each repeat pen comprising 25 chickens. The five dietary treatment groups were: T1 (Normal ambient condition + basal diet (BD), T2 (EHS +BCD), T3 (EHS + extreme heat stress diet (EHSD) prepared from BD with tallow replaced with soy oil and containing molasses 2%), T4 (EHS + EHSD prepared from BD with tallow replaced with soy oil and containing molasses 2% and methionine and lysine of 1.5 times greater quantities than in BD), and T5 (EHS + EHSD prepared from BD with tallow replaced with soy oil and containing molasses 2%, methionine and lysine of 1.5 times greater quantities than in BD, and vitamin C 200 ppm) with inverse lighting. The body weight gain of the broilers increased significantly in T4 and T5 as compared with that in T1 and T2. Weights of the lymphoid organ, bursa of Fabricius, thymus, and spleen were similar between all groups. Serum concentrations of IgG, IgG and IgM were higher in T4 and T5 than inT1 and T2, but the corticosterone concentration decreased significantly in them. In T4 and T5, Lactobacillus in the cecum increased, but Escherichia, coliform, and total aerobic bacteria decreased rather significantly, compared with those in T1 and T2. Contents of acetic acid, propionic acid and total SCFA were significantly higher in T4 and T5 than in T1 and T2.

• Journal of Nutrition and Health
• /
• v.38 no.2
• /
• pp.117-124
• /
• 2005

We investigated the effects of prolonged exposure in hot environmental condition and ingestion of fluid on various physiological variables including plasma glucose, lactate, the rating of perceived exertion (RPE), and heart rate as well as golf putting performance. Six male professional golfers were voluntarily participated in three different putting trials which were separated by seven days of time interval period. Three different putting trials were conducted at either 20℃ or 32℃, or 32℃ + Fluid ingestion. Performing 32℃ + Fluid ingestion trial, all subject ingested sport drink as much as their body mass was decreased. For each experiment, all subjects were undertaken total 48 putting, which separated by four x 12 putting in four different time points (i.e., Rest, 1 hr, 2 hr, and 3 hr). Plasma glucose concentration was significantly decreased with hot ambient condition but it was almost fully recovered by fluid ingestion. Plasma lactate concentration was significantly higher when subjects were exposed in hot environmental condition, and it did not change with fluid ingestion. There was a no different in putting performance and psychological fatigue level (performed by GRID test) at any environmental conditions. The RPE, commonly used for evaluating of physical fatigue level, was significantly dropped by fluid ingestion which indicates lower physical fatigue level. In addition to this, heart rate (HR) was also significantly decreased after fluid ingestion. Based on these results, it was concluded that the ingestion of fluid during prolonged exposure in hot ambient condition decrease the degree of physical fatigue levels and heart rate, which will possibly improve the golf performance when exposed in extreme weather condition in summer. (Korean J Nutrition 38(2): 117～124, 2005)

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1405-1405
• /
• 2011

Sudden earthquake is changing national energy stratagem for future energy resource. In case Germany, current nuke power station will be shut down with several decades. Newly constructed build in Japan must have photovoltaic system as a obligations.. As a long-term sustainable energy one, PV should give confidence to customers up to more than 20 years. Today, IEC 61215 and IEC 61646 standards are representative one for ensuring performance and safety of PV module. But it is still needed to develop more realistic test method. For example, if we think about extreme condition like desert and North Pole, the temperature condition describe in test standards can have little effect on life time expectation of PV module. Installation speed of PV system is very high, but establishing test standards are very complex and not easy. So in this paper, I tried to open the long-term test method for PV module to ensure 25 year's old life time. It is just starting point of PV related long-term test methods. The specific and technical explanation will be shown in the following paper in detail.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.60 no.6
• /
• pp.55-63
• /
• 2018

This paper aimed to characterize the spatial and temporal pattern of agricultural drought in Pre-Kharif season using Vegetation Health Index (VHI) and illustrated drought characteristics in Bangladesh during 2001-2015. VHI was calculated from TCI (Temperature Condition Index) and VCI (Vegetation Condition Index) derived from MODIS Terra satellite data, LST (Land Surface Temperature) and EVI (Enhanced Vegetation Index), respectively. The finding showed that all drought-affected areas were experienced by mild, moderate, severe and extreme droughts in several years of Pre-Kharif seasons. Significant drought events were found in the year of 2002 and 2013. On average, Chittagong district covered the largest drought area in all drought stages, and the fraction of drought area was the highest in Sylhet and Rangpur for Pre-Kharif season. Finally, overlaying annual VHI raster maps resulted in that the most vulnerable district to agricultural drought were Sylhet, Rangpur, and Mymensingh in the northern and eastern regions of Bangladesh.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.45 no.6
• /
• pp.109-118
• /
• 2003

As a fundamental research to establish a safety operation plan for irrigation dams, this study presents hydrologic analysis conducted in Sungju Dam watershed based on various rainfall data. Especially those reservoirs without flood control feature are widely exposed to the risk of flooding, a safe and optimized operation program need to be improved against arbitrary flooding. In this study, reservoir routing program was developed and simulated for reservoir runoff estimation using WMS hydrology model. The model simulated the variations of reservoir elevation under the condition of open or closed emergency gate. In case of closed emergency gate, water surface elevation was given as 193.15 m, and this value exceeds the dam crest height by 1.65 m. When the emergency gate is open, the increment of water surface elevation is given as 192.01 m, and this value exceeds dam crest height by 0.57 m. As an alternative plan, dam height increase can be considered for flood control under the PMP (Probable Maximum Precipitation) condition. Since the dam size is relatively small compare to the watershed area, sound protection can be expected from the latter option rather than emergency gate installation.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.825-829
• /
• 2005

This paper presents an approach for designing a fuzzy logic-based adaptive SVC damping In controller for damping low frequency power oscillations. Power systems are often subject to low Frequency electro-mechanical oscillations resulting from electrical disturbances. Generally, power system stabilizers are designed to provide damping against this kind of oscillations. Another means to achieve damping is to design supplementary damping controllers that are equipped with SVC. Various approaches are available for designing such controllers, many of which are based on the concepts of damping torque and others which treat the damping controller design as a generic control problem and apply various control theories on it. In our proposed approach, linear optimal controllers are designed and then a fuzzy logic tuning mechanism is constructed to generate a single control signal. The controller uses the system operating condition and a fuzzy logic signal tuner to blend the control signals generated by two linear controllers, which are designed using an optimal control method. First, we design damping controllers for the two extreme conditions; the control action for intermediate conditions is determined by the fuzzy logic tuner. The more the operating condition belongs to one of the two fuzzy sets, the stronger the contribution of the control signal from that set in the output signal. Simulation studies done on a one-machine infinite-bus and a four-machine two-area test system, show that the proposed fuzzy adaptive damping SVC controller effectively enhances the damping of low frequency oscillations.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1999.06a
• /
• pp.271-284
• /
• 1999

As a semiconductor material for electronic devices operated under extreme environmental conditions, silicon carbides (SiCs) have been intensively studied because of their excellent electrical, thermal and other physical properties. The growth characteristics of single-crystalline 4H-SiC homoepitaxial layers grown by a thermal chemical vapor deposition (CVD) were investigated. Especially, the successful growth condition of 4H-SiC homoepitaxial layers using a SiC-uncoated graphite susceptor that utilized Mo-plates was obtained. The CVD growth was performed in an RF-induction heated atmospheric pressure chamber and carried out using off-oriented substrates prepared by a modified Lely method. In order to investigate the crystallinity of grown epilayers, Nomarski optical microscopy, Raman spectroscopy, photoluminescence(PL), scanning electron microscopy (SEM) and other techniques were utilized. The best quality of 4H-SiC homoepitaxial layers was observed in conditions of growth temperature 1500$^{\circ}C$ and C/Si flow ratio 2.0 of C3H3 0.2sccm & SiH4 0.3sccm. The growth rate of epilayers was about 1.0$\mu\textrm{m}$/h in the above growth condition.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.9 no.3
• /
• pp.303-308
• /
• 1999

As a semiconductor material for electronic devices operated under extreme environmental conditions, silicon carbides(SiCs) have been intensively studied because of their excellent electrical, thermal and other physical properties. The growth characteristics of single-crystalline 4H-SiC homoepitaxial layers grown by a thermal chemical vapor deposition (CVD) were investigated. Especially, the successful growth condition of 4H-SiC homoepitaxial layers using a SiC-uncoated atmospheric pressure chamber and carried out using off-oriented substrates prepared by a modified Lely method. In order to investigate the crystallinity of grown epilayers, Nomarski optical microscopy, Raman spectroscopy, photoluninescence(PL), scanning electron microscopy(SEM) and other techniques were utilized. The best quality of 4H-SiC homoepitaxial layers was observed in conditions of growth temperature $1500^{\circ}C$ and C/Si flow ratio 2.0 of $C_{3}H_{8}\;0.2\;sccm\;&\;SiH_{4}\;0.3\;sccm$. The growth rate of epilayers was about $1.0\mu\textrm{m}/h$ in the above growth condition.

• Journal of the Semiconductor & Display Technology
• /
• v.15 no.1
• /
• pp.17-21
• /
• 2016

EUV (Extreme Ultraviolet) pellicle which protects a mask from contamination became a critical issue for the application of EUV lithography to high-volume manufacturing. However, researches of EUV pellicle are still delayed due to no typical manufacturing methods for large-scale EUV pellicle. In this study, EUV pellicle membrane manufacturing method using not only KOH (potassium hydroxide) wet etching process but also a water bath was suggested for uniform etchant temperature distribution. KOH wet etching rates according to KOH solution concentration and solution temperature were confirmed and proper etch condition was selected. After KOH wet etching condition was set, $5cm{\times}5cm$ SiNx (silicon nitride) pellicle membrane with 80% EUV transmittance was successfully manufactured. Transmittance results showed the feasibility of wet etching method with water bath as a large-scale EUV pellicle manufacturing method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.11
• /
• pp.53-58
• /
• 2015

Systemic heating and cooling air conditioning systems are popular in various industrial fields and even home. Recently, the rate of supply of this kind of multi-heat pump has been increased under ESCO financing supporting system. Generally the heat pumping system has a structural simplicity and easy installation benefits. and has good running efficiency under normal designed condition. But under extreme climate condition (over $+30^{\circ}C$, under $-10^{\circ}C$), this system exposes abnormal power consumption. It causes high progressive electric power rates and resultant peak power capacity of power plant. In this paper, a novel system concept of buffering refrigerant accumulator and constant pressure control system to relieve peak power load is proposed and this system's utility is verified with an prototype experimental system.