• 한국어병학회지
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• 제33권1호
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• pp.23-34
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• 2020

In recent years, global warming is causing dramatic environmental changes and deterioration, such as hypoxia, leading to reduced survival rate and growth performance of farmed aquatic animals. Hence, understanding systemic immuno-physiological changes in fish under environmental stress might be important to maximize aquaculture production. In this study, we investigated physiological changes in rainbow trout exposed to hypoxic stress by monitoring changes in blood chemistry, leukocyte population, and expression levels of related cytokine genes. Hematological and serological factors were evaluated in blood obtained from rainbow trout sampled at a dissolved level of 4.6 mg O₂ L^-1 and 2.1 mg O₂ L^-1. Blood and head kidney tissue obtained at each sampling time point were used to determine erythrocyte size, leukocyte population, and cytokine gene expression. The level of LDH and GPT in fish under progressive hypoxia were significantly increased in plasma. Likewise, the (Granulocyte + Macrophage)/lymphocyte ratio (%) of fish exposed to hypoxia was significantly lower than that in fish in the control group. Such changes might be due to the rapid movement of lymphocytes in fish exposed to acute hypoxia. In this study, significant up-regulation in expression levels of IL-1β and IL-6 gene appeared to be involved in the redistribution of leukocytes in rainbow trout. This is the first study to demonstrate the involvement of cytokines in leukocyte trafficking in fish exposed to hypoxia. It will help us understand systemic physiological changes and mechanisms involved in teleost under hypoxic stress.

• 한국대기환경학회지
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• 제23권4호
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• pp.405-419
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• 2007

A series of tracer experiments for the evaluation of atmospheric dispersion was performed over the urban area of Seoul using two inert, non-deposition perfluorocarbon (PMCH and m-PDCH) gases during three years campaign on 2002, 2003 and 2005. 30 sampling sites for collecting these tracers were located along two arcs of 2.5 and 5 kilometers downwind from the release point. About ten measurements which each lasted for 2 hours or 4 hours were made over the two consecutive days during each campaign. CALPUFF and MM5 meteorological model were applied to evaluate the urban dispersion in detail. Size of Modeling domain was $27\;km{\times}23\;km$ and the fine nest in the modeling domain had a grid size of 0.5 km. The results showed that CALPUFF dispersion model had a tendency to estimate tracer concentrations about $2{\sim}5$ times less than those of ambient samples under many conditions. These consistent inaccuracy in urban dispersion was attributed to inherent inaccuracy and lack of details in terrain data at urban area.

• 전기학회논문지P
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• 제58권4호
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• pp.391-396
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• 2009

In this paper, a control algorithm for DC-Link voltage unbalancing compensation of a four-switch inverter for a three-phase BLDC motor drive is proposed. Compared with a conventional six-switch inverter, the split source of the four-switch inverter can be obtained by splitting DC-link capacitor into two capacitors to drive the three phase BLDC motor. The voltages across each of two capacitors are not always equal in steady state because of the unbalance in the impedance of the DC-link capacitors $C_1$ and $C_2$ or the variable current flowed into the capacitor's neutral point in motor control. Despite the unbalance, if the BLDC motor may be run for a long time the voltage across one of the capacitors is more increased. So the unbalance in the capacitors voltages will be accelerated. As a result, The current ripple and torque ripple is increased due to the fluctuation of input current which flows into 3-phase BLDC motor. According to that, the vibration of motor will be increased and the whole system will be instable. This paper presents a control algorithm for DC-Link voltage unbalancing compensation. The sampling from the voltages across each of two capacitors is used to perform the voltage control of DC-Link by using the feedforward controller.

• 한국대기환경학회지
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• 제14권5호
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• pp.479-490
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• 1998

The concentrations of ten inorganic (sodium, chloride, sulfate, ammonia, etc.) and three organic (acetate, formate, and MSA) ions associated with airborne particulate matter were measured from Cheju Island, Korea during the three field intensive campaigns conducted in (1) Sept./oct. 1997 (fall), (2) Dec. 1997 (winter), and (3) April 1998 (spring). The results of our measurements indicated that the concentration levels of most ionic species were decreasing significantly across the three experimental periods. The patterns of concentration reduction were clear as the sum of all cation and anion species changed dramatically across those periods such as 294> 144 > 65 and 193 >96>74 nequiv/m3, respectively. The changes were best explained in terms of the wind rose patterns of the study site. Since our sampling spot is located on the western-end point of Cheju Island, it is likely to reflect the effects of diverse sources such as natural, marine processes during NW and local non-maritime ones during SE winds. .Hence, the periodical changes in ionic concentrations may be accounted for by the comparable changes in wind direction. To further investigate environmental characteristics of these ionic components, correlation analysis was conducted not only between meteorological and ion data but between different ion-pairs. The results of these analyses confirm that the concentration levels of ionic species are strongly affected by wind speed and temperature and that there are certain patterns between ion species to which such effects apply. In light of the significance of the wind rose patterns in the area, we further extended these analyses into four data groups that were divided on the basis of wind direction. The results of these analyses showed that the strength of correlations between important pairs (e.g.:. between windspeed and most of major inorganic species including sodium and chloride) can be ranked on the distribution of major ions are very diverse, depending on data grouping scheme for such analysis. The results of this study thus suggest that environmental behavior of chemical components be analyzed in various respects, rather than simple standard, especially if measurements are made in complex environmental condition under which both natural and anthropogenic effects are competing each other.

• 모자간호학회지
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• 제3권2호
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• pp.126-141
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• 1993

The purpose of this study was to understand the pattern of the pregnant women' attitude on breast feeding. The research had been proceeded as follows ; 1. Delineation of the Q-population the statements of Q-population had been derived from review of the related literature and a open-ended questionnaire filled by nurses, nursing students, general public, and the pregnant women. Total number of concourse collected was 105. 2. Selection of the Q-sample : Among 105 concourse, those which has obscure or overlapped were deleted. 38 concourse were selected finally. 3. Selection of the P-sample : by the convenient sampling technique, 28 subjects had been deter mined among the pregnant women who visited a hospital affiliated with university for the antenatal care, from March to August, 1993. 4. Q-sorting : based on 1 to 9 point scale (forced normal distribution), the selected P-sample rated their operant definition of breast feeding. 5. Determination of Q-type : with Q-sorts, PC-Quanal program identified the three Q-types. 6. Analysis of Q-type : the characteristics of three different attitude had been analyzed based on the typal array, extreme comments, and subject$\sim$s demographic information. The results revealed that there are three different altitudes nth regard to breast feeding : Instinct oriented attitude, Science oriented attitude, and Convenience oriented altitude. Mothers with Instinct oriented attitude and Science oriented altitude are thought to have high possibility to breastfeed their infant willingly, and mothers with Convenience oriented attitude to breast feed under the favorable conditions. These findings can be used as the information giving data for the education to encourage breast feeding.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.413-422
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• 1993

Air shipment affords the quickest possible delivery of horticultural products. The price of air shipped horticultural products are relatively high as most of these products are perishable. Usually the temperature in the cargo compartment is not controlled during flight. Thus, special attention should be paid to procooling prior to shipment. The environmental condition during transportation of horticultural products is an essential parameter for maintaining the quality of perishable products. Commonly horticultural products were loaded by ULD(Unit Load Devices) as a container or pallet in the aircraft (except for small aircraft) . Therefore, inside temperature of the container and cargo compartment came into question. Scarce literature on the relationship between environmental condition and quality changes of horticultural products during air shipment can be found. By the stand point of keeping fresh quality, investigations on the actual condition of air shipments were carried out to improve the technique during the distribution process of fresh horticultural products. Temperature, humidity, atmospheric pressure, carbon dioxide, ethylene, impacts, and changes in quality during the air shipment of snapbeans, okras and chrysanthemums were measured. Temperature was measured by recording thermometers, relative humidity by recording hygrometers, atmospheric pressure by a strain -guage type pressure sensor, carbon dioxide by testing tubes, ethylene by sampling bags and a gaschromatograph, impacts and vibrations by impact recorders and a 3D accelerometer. Relationships between environmental conditions and quality changes during air shipments were clarified. It was expected from investigations into actual shipments that the ventilation and insulation properties of air freight containers were related to the quality of agricultural products. Aircraft can no directly load and unload trucks into them. The transshipment is inclined to cause shocks and vibrations, and to invite damages within a short time.

• 한국농공학회논문집
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• 제47권3호
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• pp.77-86
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• 2005

A monitoring study has been conducted to identify hydrologic conditions, water quality and nutrient loading characteristics of small watershed in Juam Lake. Climate data of the watershed were collected; flow rate was measured and water quality sampling was conducted at the watershed outlet for this study. Water quality data revealed that T-P concentrations meet I grade of lake water quality standard during non-storm period, but degraded up to II-III grade of lake water quality standard during storm period. The observed T-N concentrations always exceeded lake water quality standard. Therefore, T-P was identified as limiting chemical constituent for eutrophication of Juam Lake. T-P concentration of non-storm period also revealed that point source pollution is not serious in the watershed. Three year monitoring results showed that the observed T-N losses were $10.85\~18.88$ kg/ha and T-P losses were $0.028\~0.323$ kg/ha during six month (Mar. - Oct.), respectively. Major portion of runoff amount discharged by a few storm events a year and nutrient load showed apparent seasonal variation. Huge runoff amounts were generated by intense storms, which make application of water treatment or detention facilities ineffective. Monitoring results confirmed that water quality improvement by abating nonpoint source pollution in rural watershed of monsoon climate should be focused on source control. T-P losses from paddy field seemed to consist of significant amount of total load from study watershed. Therefore, management of drainage from paddy field is considered to be important for preventing algal blooming problem in Juam Lake.

• 한국콘텐츠학회논문지
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• 제18권7호
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• pp.350-361
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• 2018

본 연구는 사회복지사의 전문성과 서비스 질의 관계에서 사회자본의 매개효과를 실증분석 하였다. 편의 표집방법으로 충청북도 지역 사회복지사를 대상으로 수집한 자료(276개 사례)를 활용하여 기술통계 및 위계적 회귀분석을 실시하였다. 기술통계 결과는 5점 리커트 척도에서 사회복지사 전문성 3.36, 사회자본의 하위유형 중 네트워크는 3.43, 신뢰는 3.67 및 서비스 질 4.00점의 평균값을 보였다. 사회복지사의 전문성과 서비스 질의 관계에서 사회자본의 하위유형인 네트워크와 신뢰는 각각 부분매개효과를 지니고 있는 것으로 검증되었다. 즉, 사회복지사의 전문성이 높으면 네트워크와 신뢰가 확대되고, 확대된 네트워크와 신뢰는 서비스 질을 향상시키는 유의한 영향력이 확인되었다. 분석결과를 토대로 서비스 질을 높이기 위한 방안으로서의 사회자본의 활성화를 위한 이론적 및 실천적 함의를 제시하였다.

• 대한간호학회지
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• 제42권5호
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• pp.622-631
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• 2012

Purpose: The purpose of this study was to identify health knowledge, health promoting behavior and factors influencing health promoting behavior of North Korean defectors in South Korea. Methods: Participants in this study were 410 North Korean defectors, over 20 years of age residing in Seoul. They were recruited by snowball sampling. Data were collected from April to June, 2010. Health knowledge, health promoting behavior, self-efficacy, perceived barriers to health promoting behavior and social support were measured by structured questionnaires, and perceived physical and mental health status were measured by one item with 10-point numeric rating scale. The data were analyzed using t-test, ANOVA, and multiple regression. Results: Health knowledge, health promoting behavior, and perceived barriers to health promoting behavior were moderate while self-efficacy and social support were high. Factors influencing health promoting behavior of the participants were found to be self-efficacy, social support and perceived barrier to health promoting behavior. Conclusion: The results of this study indicate that nursing intervention programs enhancing self-efficacy, social support and reducing perceived barriers to health promoting behavior need to be developed for North Korean defectors in South Korea.

• 전자공학회논문지D
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• 제36D권7호
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• pp.56-65
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• 1999

본 논문에서는 광 상호연결에 응용되기 위한 소자로서, $5{\times}5$ 스폿을 제어하기 위한 이진위상의 화소형 회절격자의 설계에 유전 연산자로서 복제, 교배, 돌연변이 연산자만을 이용한 aGA를 적용하여 그 특성을 분석하였다. 신뢰성 있고, 효율적인 기법으로 증명되고 있는 GA를 적용하기 위하여, 염색체의 크기는 $32{\times}32$로하고, 이진 스트링으로 부호화하였다. 또한 확률적 샘플링 에러를 감소시키기 위하여 순위 기법을 적용하여 복제하였고, 블록의 크기를 $16{\times}16$으로 하여, 단일점 교배법으로 격자를 설계하여 재생된 스폿을 얻은 결과, 돌연변이 확률은 0.001, 교배 확률을 0.75, 개체군의 크기를 300으로 할때, 정량적으로 74.7[%]의 높은 회절효율과 $1.73{\times}10^{-1}$의 안정된 균일 분포를 갖는 최적 값을 얻을 수 있었다.