• 한국농공학회지
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• 제36권1호
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• pp.95-102
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• 1994

Since parameters influencing the indoor environment of livestock building interrelate so complicatedly, it is of great difficulty to identify the exact cause of environmental problems in a livestock building. Therefore, the approaches for the problem solving based on experience not numerical calculation will be helpful to the management of livestock building This study was attempt to develop the decision supporting system to diagnose environmen- tal problems in a livestock building based on an expert system and a neural network. HClips$^3$), attaching the Hangeul user interface to Clips which is known as a powerful shell for develop- ing expert system, was used. The multilayer perceptron consisting of 4 layers including back propagation learning algorithm was adpoted, which was rapidly converged within the allowable range at 50,000 learning sweeps. The expert system and neural network seemed to work well for this specific application, providing proper suggestions for some environmental problems: particularly, the neural net- work trained by an environmental problem and its corresponding answer with certainty factor, produced the same results as those by expert system.

• 한국자원식물학회지
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• 제12권3호
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• pp.215-220
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• 1999

전남지방의 고로쇠나무 수액에 대해 sucrose, 무기물, phenol화합물을 분석한 결과는 다음과 같다. 1. Sucrose의 함량은 일반적으로 2차 채취시기에 높게 나타났으며, 지역에 따라 차이는 있으나 2∼3%정도였다. 채취방법은 사구법이 천공법보다 높게 나타났다. 2. ToTal phenol화합물 역시 2차 채취시기에 높게 나타났으며, 0.034∼0.151 mg/100ml의 수준이었고, 가장 다량 함유된 phenol화합물은 phloroglucinol이었으며, 역시 사구법에서 천공법보다 높게 나타났다. 3.무기물의 경우 역시 2차 채취시기에 높게 나타났으며, 역시 사구법에서 천공법보다 높게 나타났다.

• 약학회지
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• 제49권2호
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• pp.174-179
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• 2005

The human skin is constantly exposed to environmental irritants such as ultraviolet, smoke, chemicals. Free radicals and reactive oxygen species (ROS) caused by these environmen tal facts play critical roles in cellular damage. These irritants are in themselves damaging to the skin structure but they also participate the immensely complex inflammatory reaction. The purpose of this study was to investigate the skin cell protective effect of Campsis grandiflora extract on the UVB-irradiated human dermal fibroblasts (HDFs). We tested free radical and superoxide scavenging effect in vitro. C. grandiflora extracts had potent radical scavenging effect by 82% at $100{\mu}g/ml$, respectively. For testing intracellular ROS scavenging activity the cultured HDFs were analyzed by increase in DCF fluorescence upon exposure to UVB 20 $MJ/cm^2$ after treatment of C.grandiflora extracts. The results showed that oxidation of CM-DCFDA was inhibited by C.grandiflora extracts effectively and C.grandiflora extracts has a potent free radical scavenging activity in UVB- irradiated HDFs. In ROS imaging using confocal microscope we visualized DCF fluorescence in HDFs directly. In conclusion, our results suggest that C.grandiflora can be effectively used for the prevention of UV-induced adverse skin reactions such as radical production, and skin cell damage.

• 한국세라믹학회지
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• 제35권10호
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• pp.1020-1029
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• 1998

The reaction-bonded TiC-Ni/Si/Co composites were prepared by the melt infiltration of Co, Si, and Ni me-tal into the TiC preforms. The miocrostructure reaction composition and mechanical properties were in-vestigated. In the case of the melt infiltrated with Co and Ni TiC grain shape was changed from angular to spherical shape with the average grain size of ∼5$\mu\textrm{m}$. In the case of the melt infiltrated with Co/Si or Ni/Si, Si was reacted with TiC particles and formed SiC particles. The bending strength of both specimens which have atomic ratio of 3 were 710 MPa and 515 MPa respectively. In the case of the melt infiltrated with Ni/Si/Co,. nonstoichiometric TiC was formed and its bending strength decreased to 420 MPa.

• 한국식품영양학회지
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• 제12권1호
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• pp.85-90
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• 1999

The characcteristics of anthocyanin pigments from crab apple (Malus prunifolia Wild. Borkh. "red fruit") by ethanol extract were investigated at various condition of light temperature sugar, organic acid me-tal ion and pH. The pigments were stable(over the 60%) on the light irradiation throughout 20 days sto-rage period at room temperature and in the pesenc of Al-foil red blue green and yellow cover were rage period at room temperature and in the pesence of Al-foil red blue green and yellow cover were very stable. The pigments also showed high thermal stbility(over the 67% at 115$^{\circ}C$ 10min) at pH2.5 respectively. The pigments with added organic acid greatly increased thickness of red color. The pig-ments with added metal ions at pH 2.5 such as Na+ K+, Mg2+ Ca2+ and Mn2+ were stable throughout 20 days storage period at $25^{\circ}C$. But Cu2+ addition showed the rapidly degradation of the pigments and Al3+ addition induced the color conversion from red to redish violet. The thickness of the red color of anthocyanin pigments increased increased as the pH decreased. These results indicated that crab apple antho-cyanin pigments might be potental source of natural food colorant. colorant.

• 한국구조물진단유지관리공학회 논문집
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• 제14권3호
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• pp.178-185
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• 2010

본 논문은 구조물의 기초지지력에 안정성 평가를 위해서 연구되었다. 구조물의 하부에 설치된 기초의 저면은 지반과 접촉하게 되는데 지반유실 및 기타원인으로 인해 기초와 지반의 접촉면 일부분이 손실되었을 때 접촉비율에 따라 나타나는 지지력안정성을 분석하기 위해서 시행되었다. 이를 위해 기초저면과 지반의 접촉비율을 정량적으로 조절하여 수치해석 및 모형실험으로 지지력 거동을 분석한 결과 기초저면과 지반의 접촉율이 75% 이상일 경우에는 기초의 지지력이 크게 저하되지 않는다는 지지력 안정성 기준을 확립하였다.

• 한국조명전기설비학회지:조명전기설비
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• 제7권3호
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• pp.27-33
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• 1993

본 논문은 캐리어 주파수 20kHz 이상의 고주파 전압형 PWM 인버터를 구동하기 위한 디지털 제어기에 관한 연구이다.적절한 PWM 패턴을 선택하기 위하여 기존의 PWM을 분석하였고, 비동기형 계단 정현파를 기준신호로 하여 제어기의 PWM 패턴을 구하였으며, PWM 제어방법은 가변 캐리어 비를 이용하였다.PWM 제어기는 모두 디지털 방식으로 구성하였다. 특히, 제시된 제어기의 구성은 연산 및 데이터 처리와 PWM 패턴 합성을 8비트 원칩 마이크로프로세서와 디지털 로직으로 나누어 설계하므로써 제어에 대한 속응성 및 제어성을 개선하였다. 또 변조도 데이터를 9비트로 출력하도록 프로그램을 적절히 이용하여 데이터 처리능력을 높였다.디지털 제어기는 회로구성을 i8051과 원칩 EPLD로 구성하였고, 설계된 제어기는 전압형 인버터를 동작시켜 제어성을 고찰하였다. 그리고 전압형 인버터 시스템의 고조파와 전류파형을 평가 분석하였다.

• 대한영양사협회학술지
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• 제20권1호
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• pp.12-25
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• 2014

The calcium intake of elementary school students residing in Gyeongsangbukdo province from their school foodservice and milk program was evaluated. A total of 252 subjects (50.4% boys and 49.6% girls) were examined. A significant percentage of the total subjects (32.9%) reported skipping breakfast once or more per week, with the major reasons for skipping breakfast being a lack of time and appetite. A majority of the to-tal subjects (78.2%) participated in the school milk program. The type of milk consumed by the subjects was mainly white milk, with a milk intake mostly between one and two cups. Participants in the school milk program consumed over the recommended nutrient intake (RNI) of calcium, but non-participants consumed only 48.1% of the RNI (P<0.001). The calcium intake rate according to food cooking methods, from highest to lowest was in the order bap, twigim, jeon, jjim, and gui. Although the food intake rate of guk was low, the calcium intake rate by RNI was the highest for guk. On the other hand, the food intake rate of bap and kimchi was high, but their calcium intake rate by RNI was relatively low. These results show that non-participants in the school milk program are significantly deficient in calcium. Therefore, to improve the calcium nutrition for children, school lunch menus containing high calcium need to be developed and children should be encouraged to enter a school milk program.

• 수산경영론집
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• 제22권2호
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• pp.53-74
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• 1991

Interest on ocean environment has increased with the development of industrialized activities. Public marine resorces are defined broadly to include fish stocks, beaches, marine waters, recreational fishing, biota, waterfowls, shorebirds, seabirds and marine mammals But, it is not easy to analyze compensation for injury to publicly owned marine resources because the claimants do not exist clearly and the economic methodology of damage on public goods is not developed fully. This paper introduces basic idea of welfare economic theory and environmental legislation to the research question : How the economics and law can be applied to the case of damage on publicly owned marine resource. The paper discusses the concepts of willingness to pay (WTP) and willingness to accept (WTA). It is accepted generally that WTA is correct concept of welfare change in the case of damaged public goods. Four methods (compensating variation, equivalent variation, compensating surplus, equivalent surplus of measuring welfare changes are compared. Compensating variation(CV) is the best measure of welfare changes are compared. Compensating variation(CV) is the best measure of welfare changes caused by environmental damage. Vartia (1983) showed CV could be measured from the ordinary demand function using the differential equations. This paper also provides an overview of the emerging U.S. and Korea legal system for compensation for natural resource damages, with particular emphasis on U.S. legal system under Comprehensive Environmen-tal Response Compensation and Liability Act (CERCLA). These regulations are to include two different types of standardized procedures for assessing natural resources injury : Type A or simplified assessment techniques for small releases ; and Type B protocols that would include detailed and extensive assessment methodologies for major releases. Type A procedures are specified by Natural Resources Damage Assessment Model for Coastal and Marine Environment (NRDAM/CME) of the U.S. CERCLA provides a legal 'legitimization for the use of economic-based nonmarket valuation in the courts and have introduced appropriate and accurate nonmarket valuation methods based on willingness to-pay for damage assessment. By briefly reviewing economic theory and environmental legislation, we hope to help provide a better understanding of the compensation process and the economics of publicly owned marine resources in the U.S. and to integrate the economics and law of natural resources valuation into a single comprehensive package in Korea.

• 한국대기환경학회지
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• 제25권5호
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• pp.392-401
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• 2009

Ice-crystal clouds observation was conducted using a GIST/ADEMRC Multi-wavelength Raman lidar system in order to measure vertical profile and optical depth at Gwangju ($35^{\circ}$10'N, $126^{\circ}$53'E), Korea in December 2002, and March and April 2003. Ice-crystal clouds at high altitude can be distinguished from atmospheric aerosols by high depolarization ratio and high altitude. Ice-crystal clouds were observed at 5~12 km altitudes with a high depolarization ratio from 0.2 to 0.5. Optical depth of ice-crystal clouds had varied from 0.14 to 1.81. The radiative effect of observed ice-crystal cloud on climate system was estimated to be negative net flux in short wavelength (0.25~$4.0{\mu}m$) and positive net flux in short+long wavelength (0.25~$100{\mu}m$) at top of the atmosphere. Net flux by ice-crys tal cloud per unit optical depth was comparable to that of Asian dust.