• Journal of Electrical Engineering and Technology
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• 제1권2호
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• pp.216-225
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• 2006

This paper presents a new circuit topology of DC busline switch and snubbing capacitor-assisted full-bridge soft-switching PWM inverter type DC-DC power converter with a high frequency link for low voltage large current applications as DC feeding systems, telecommunication power plants, automotive DC bus converters, plasma generator, electro plating plants, fuel cell interfaced power conditioner and arc welding power supplies. The proposed power converter circuit is based upon a voltage source-fed H type full-bridge high frequency PWM inverter with a high frequency transformer link. The conventional type high frequency inverter circuit is modified by adding a single power semiconductor switching device in series with DC rail and snubbing lossless capacitor in parallel with the inverter bridge legs. All the active power switches in the full-bridge inverter arms and DC busline can achieve ZVS/ZVT turn-off and ZCS turn-on commutation operation. Therefore, the total switching losses at turn-off and turn-on switching transitions of these power semiconductor devices can be reduced even in the high switching frequency bands ranging from 20 kHz to 100 kHz. The switching frequency of this DC-DC power converter using IGBT power modules is selected to be 60 kHz. It is proved experimentally by the power loss analysis that the more the switching frequency increases, the more the proposed DC-DC converter can achieve high performance, lighter in weight, lower power losses and miniaturization in size as compared to the conventional hard switching one. The principle of operation, operation modes, practical and inherent effectiveness of this novel DC-DC power converter topology is proved for a low voltage and large current DC-DC power supplies of arc welder applications in industry.

• Asian-Australasian Journal of Animal Sciences
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• 제24권7호
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• pp.912-918
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• 2011

Newly born lambs have to face challenges in a new environment totally different from that of the uterus. Adaptation to extra-uterine life involves functional changes with almost each organ and system in the body undergoing a series of metabolic and anatomical modifications. Failure to adapt the extra-uterine environment can not only lead to homeostatic disturbances but also lead to the death of the affected lambs. Hematological parameters of newly born lambs show variability that differs between breeds of lambs. The purpose of present study was to determine homeostatic responses and physiological reference values in Kajli breed lambs occurring in the neonatal period through changes in blood profile, respiratory rate, heart rate, live weight and rectal, scrotal and skin temperatures. For this purpose, sixteen clinically fit lambs (males = 10 and females = 6) with a mean body weight $6.92{\pm}0.46$ kg were selected. Physiological data of selected parameters of each Kajli lamb was recorded at three day intervals and hematological parameters at five days for a period of 30 days. In general, statistical analysis showed a significant effect of time (p<0.001) on all the studied physiological and hematological parameters except platelets counts, white blood cells and hemoglobin concentration. The results documented in the current study are an addition to existing knowledge of the physiology of Kajli sheep breed should be helpful in developing feeding, disease diagnoses and treatment protocols for newborn Kajli stock.

• Journal of Plant Biotechnology
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• 제2권2호
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• pp.55-60
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• 2000

Experiments initiated 30 years ago to obtain selectable markers have led to a series of studies of Trp biosynthesis and anthranilate synthase (AS) the control enzyme using largely plant tissue cultures since they have experimental properties that can be readily exploited. Enzymological and compound feeding studies provided evidence that AS is the control point in the Trp biosynthesis branch and that altering the AS feedback control by the selection of mutants resistant to the Trp analog 5-methyl-tryptophan (5MT) can lead to the overproduction of this important amino acid. Plants regenerated from these Trp overproducing lines of most species also had high free Trp levels but Nicotiana tabaum (tobacco) plants expressed the feedback altered AS only in cultured cells and not in the regenerated plants. further tests by transient and stable expression of the cloned promoter for the naturally occurring tobacco feedback-insensitive AS, denoted ASA2, confirmed the tissue culture specific nature of the expression control. The 5MT caused by the expression of a feedback-insensitive AS from tobacco has been used to select protoplast fusion hybrids with several species since the resistance is expressed dominantly. Recently the ASA2 gene has been used successfully as a selectable marker to select transformed Astragalus sinicus and Glycine max hairy roots induced by Agrobactetium rhizogenes. These results show that the ASA2y-subunit can interact with the y-subunit of another species to form active feedback-insensitive enzyme that may be useful for selecting transformed cells. Plastid DNA transformation of tobacco has also effectively expressed ASA2 in the compartment in which Trp biosynthesis is localized in the cell.

• 농촌계획
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• 제12권3호
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• pp.97-106
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• 2006

In this study was investigated the value of rural residence in later life from the personal, regional, and national perspective. For this purpose, a three-round Delphi technique was used to collect data through a series of surveys to obtain the consensus of a group of 38 experts in value of rural residence in later life in the future. In the first round was sent to them unstructured questionnaire and in the second and third round, the summarized results of the first and second round were delivered to rate the importance of each item for confirmation and validation of the results. Data were analyzed using content analysis and descriptive statistics. The major findings of this study are as follows: First, the personal, regional, and national value of rural residence in later life was selected 7 domains 23 items, 4 domains 22 items, and 3 domains 20 items respectively. Experts consented that the value from the personal perspective will be the highest among 3 perspectives. Second, as the value of rural residence from the personal perspective, it was showed nature-friendly life, physical health emotional serenity, lower expenditure, enjoyable filming, feeding the safe food, and etc,. As the value of it from the regional perspective was showed usage of retirees' speciality and experience to community development and the increase of recreational function in the rural. Also, from the national perspective, it was showed the sustainability of the rural, the establishment of welfare base, balanced development between regions. Based on these results, policy implications were discussed.

• 대한간호학회지
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• 제40권3호
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• pp.359-366
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• 2010

Purpose: The purpose of this study was to determine the significant factors for risk estimate of aspiration and to evaluate the efficiency of the dysphagia assessment tool. Methods: A consecutive series of 210 stroke patients with aspiration symptoms such as cough and dysphagia who had soft or regular diet without tube feeding were examined. The dysphagia assessment tool for aspiration was compared with videofluoroscopy using Classification and Regression Tree (CART) analysis. Results: In CART analysis, of 34 factors, the significant factors for estimating risk of aspiration were cough during swallowing, oral stasis, facial symmetry, salivary drooling, and cough after swallowing. The risk estimate error of the revised dysphagia assessment tool was 25.2%, equal to that of videofluoroscopy. Conclusion: The results indicate that the dysphagia assessment tool developed and examined in this study was potentially useful in the clinical field and the primary risk estimating factor was cough during swallowing. Oral stasis, facial symmetry, salivary drooling, cough after swallowing were other significant factors, and based on these results, the dysphagia assessment tool for aspiration was revised and complemented.

• 한국환경보건학회지
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• 제12권1호
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• pp.47-54
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• 1986

The purpose of the study is to determine the effects of sodium alginate on the suppression of organ accumulation of heavy metals were tested by mice. The seventy mice were divided into the control group and the experimental groups. The mice of cadmium group were subdivided into three groups by dose of 10 ppm cadmium group, adding 1% sodium alginate to the diets contaminated with 10 ppm cadmium group and adding 10% sodium alginate to the diets contaminated with 10 ppm cadmium group. The mice of copper group were subdivided into three groups by dose of 10 ppm copper group, adding 1% sodium alginate to the diets contaminated with 10 ppm copper group, and adding 10% sodium alginate to the diets contaminated with 10 ppm copper group. After the series of feeding of twenty-one days, the mice were killed and examined. Organs and feces were removed and analyzed for cadmium and copper amounts. The results obtained were as follows 1. As for average body weight gains, those of control group mice were the highest than heavy metal group and those of adding 10% sodium alginate to the diets contaminated with 10 ppm copper group the lowest. 2. The amount of cadmium accumulated in liver and kidney was higher than blood. The amount of cadmium in organs was higher in cadmium group than adding sodium alginate to the diets contaminated with cadmium group. 3. The amount of copper in liver was the highest, and that of copper in blood was the lowest. 4. The excretion of heavy metals was promotioned by adding 10% sodium alginate to the diets contaminated with 10 ppm heavy metal. ( P < 0.05 ).

• 한국양식학회지
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• 제12권4호
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• pp.255-266
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• 1999

The early development, growth, and morphological changes of Tiger puffer Takifugu rubripes are described on the basis of a seres of a series of reared specimens. Detailed o수 the early developmental stages are illusrtated withe special reference to morphological transformation. Egg and sperm of puffer fish Takifugu rubripes were obtained from mature adults under natural conditions, ferilized artificially and incubated in the laboratory. The incubation period of fertilizd eggs was 160 to 180 hours at a temperature of $15.1~ 18.0^{\circ}C$. Larvae were fed successively with rotifer, Artemia nauplii and artificial food for 90 days. The mean total length of newly-hatched larvae was about 2.8mm. Mouth opening occurred on the 1- day yolk-sac larvae and initial feeding was observed on th 4-5 days after hatching . The morphological transitions from the larvae to juvenile and juvenile and juvenile to young stages occurred when fish reached about 10mm in total length(about 30 days after hatching) and about 32mm in total length(about 60days after hatching) , respectively. The coefficient of variation in total length distribution increased with growth. Following the appearance of its peak at the size of about 18mm in total length, the coefficient value declined. Many changes in proportion of the body parts to total length were observed at about 9~10mm and 30~33mm in total length, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. Also one big morphological change was observed at about 18mm in total length that divide the juvenile stage into two sub-stages.

• 한국수산과학회지
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• 제22권5호
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• pp.332-341
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• 1989

경상남도 일광 연안으로 흘러내리는 하천의 하구 기수역에서 미끈날망둑온 채집하여 이석과 위내용물을 분석하여, 자치어기의 나이, 성장율 및 식성을 추정하였다. 이석 미세성장선의 하루주기성은 약 15일 간격으로 연속하여 채집된 어류 이석을 각 채집일을 감안하여 성장선 배열의 공통성을 비교 분석하여 증명하였다. 체장의 성장은 Gompertz의 식으로 유의하게 표시되었다. $L=5.73{\cdot}\;e^{15.06}(1-e^{-0.0015t})$관찰 범위에서 체장의 일일성장율은 부화 후 $50\~60$일 사이에는 0.40 mm/day로 작았으나 자라면서 빨라져 $90\~100$일 사이에는 0.85 mm/day로 증가하였다. 위내용물 분석 결과, 미끈날망둑은 전형적인 육식성 어종으로 밝혀졌는데, 주된 먹이생물은 polychaetes, amphipods, copepods 였으며 이들은 위내용물의 대부분을 차지하였다. 미끈날망둑은 성장에 따라 다소 먹이 선택에 있어 변화를 보이는데, $15\~30$mm 크기군에서는 copepods가 비교적 많이 섭이 되었지만, 성장함에 따라 amphipods의 섭이가 증가되었다. 한편 polychaetes의 선호도는 모든 크기군에 걸쳐 가장 높았다.

• 한국수산과학회지
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• 제7권4호
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• pp.179-186
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• 1974

1973년 4월부터 1974년 6월 말까지 뱀장어의 효과적인 초기사육을 위하여 일연의 실험을 한 결과는 다음과 같다. 1. 뱀장어의 초기사육의 최적성장수온은 $20\~34^{\circ}C$의 범위내에서 실험한 결과 $30^{\circ}C$로 나타났다. 2. $20\~30^{\circ}C$ 사이에서 10일간의 성장배수는 R=0.0056296$T^{1.80740}$이라는 곡선식으로 나타났다. 3. 오랫동안 축양하여 두었던 실뱀장어도 채포후 바로 사육하는 것에 비해 성장이 나쁘지 않았다. 4. 사육중 크지 않고 성장이 나빴던 것도 이번 시험사육결과 정상적인 성장을 하였다. 5. ammonia는 5ppm 이하에서는 섭이에 영향을 주지 않으나 6ppm에서는 섭이량이 현저히 줄었다. 6. 뱀장어의 고밀도 사육시 배설물의 제거는 좋은 수질을 유지하는 데 매우 중요하다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권9호
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• pp.1296-1303
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• 2000

A series of four experiments was conducted to compare nutritional values of decorticated sunflower meals against soybean meal, in diets for pigs from weaning (Exp. 1 and 2) to finishing (Exp. 3 and 4). All experimental diets were prepared compensating for the energy content by using vegetable oil and the lysine content was matched using synthetic L-Lysine HCl. Twenty-one day old pigs were fed either corn-soybean meal based diet (CSBM) or corn- twice-decorticated sunflower meal based diet (CDSM) for four weeks (Exp. 1). There was no difference in performances between treatment groups. In Exp. 2, corn-non-decorticated sunflower meal based diet (CNSM) was added to the existing two treatments. Twenty-one day old pigs were fed three experimental diets for four weeks. Pigs fed CNSM had a lower weight gain and feed intake than other treatments (p<0.05). There was no difference between pigs fed CSBM and CDSM (Exp. 2). Growth performance of growing pigs was also greater (p<0.05) in pigs fed corn starch-twice- decorticated sunflower meal based diet (CSDSM) than pigs fed corn starch-non-decorticated sunflower meal based diet (CSNSM) during the eight week feeding trial (Exp. 3). There was no difference between pig fed corn starch-soybean meal based diet (CSSBM) and CSDSM (Exp. 3). In Exp. 4, growing pigs were fed three experimental diets (CSBM, CDSM, and barley-twice- decorticated sunflower meal based diet; BDSM) until the slaughter. There was no difference in growth performance of pigs during growing and finishing periods among treatments. However, pigs fed CSBM had a higher carcass dressing percentage (p<0.05) than pigs fed CDSM and BDSM. Pigs fed BDSM diet had a lower fat tissue percentage than other groups (p<0.05). The twice-decorticated sunflower meal can be used as a substitute for soybean meal in pig diets. The performances of piglets and growing-finishing pigs were not affected when soybean meal was replaced by twice-decorticated sunflower meal. This substitution needs the contribution of synthetic lysine and vegetable oil as sources of complementary nutrients to match the nutrient profile.