• The Korean Journal of Ecology
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• v.25 no.2
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• pp.83-91
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• 2002

This study was carried out to classify forest vegetation of the Mt. Naeyeon with phytosociological analysis of ZM school and to explain ordination of communities with CCA. The research sites were located between the northern part of Pohang-si area and the southern part of Yeongdeok-gun area. The 70 plots consisted of 253 species were investigated. The forest vegetation was classified into Quercus mongolica community, Q. variabilis community, Pinus densiflora community, Carpinus laxiflora community and Zelkova serrata community. Q. mongolica community was divided into 2 groups such asRhododendron schlippenbachii group and Euonymus oxyphyllus group and Q. variabilis community was divided into 3 groups such as Syneilesis palmata group, Lespedeza × tomentilla group and Tilia mandshurica group, and Z. serrata community was divided into 2 groups such as Carpinus cordata group and Diospyros lotus group. According to the results of CCA ordination, Q. mongolica community showed high positive correlation to altitutde and topography, whereas it showed negative correlation to bare rock. Buck Z. serrata community showed the opposite tendency to Q. mongolica community. Altitude was considered as the most important factor among 5 environmental variables in the correlation with axes.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.29-34
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• 2008

The aim of the study was to investigate the effect of dietary fish oil supplementation on the semen characteristics of the Markhoz buck. Sixteen bucks were randomly allocated into 4 groups and received four different diets: unsupplemented control diet, supplemented with fish oil at 2.50% dry matter (DM), supplemented with fish oil (2.50% DM) and vitamin E (0.30 g/kg DM), and supplemented with vitamin E (0.30 g/kg DM). All experimental diets were formulated according to AFRC (1998). Semen was collected at 14 d intervals from June 17, 2006 to September 2, 2006. Semen characteristics were evaluated. Significant effects (p<0.05) of the week (sampling time) were observed for all parameters except semen volume. Also a significant effect (p<0.05) of dietary treatment was observed for all parameters except for percent sperm with normal morphologies and semen volume. Fish oil supplementation with excess vitamin E had a significant effect (p<0.05) on total number and sperm density, motility and progressive motility, percentage viability and dead sperm. The interaction between fish oil feeding and sampling time was significant (p<0.05) for all of the parameters. The bucks that received fish oil in association with vitamin E, effect fish oil showed the greatest improvement in semen characteristics compared with the other groups (p<0.05). This study showed that fish oil supplementation with vitamin E may have a beneficial effect on the semen quality and fertility of Markhoz bucks.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.213-220
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• 2013

The purpose of this study was to search stigma experiences of family members who take care of their mental illness patients. Participants consist of three parents, one child, one brother of mental illness patient. The period to collect data was from June to October 2010. We collected the data through depth interview with participants and observance of them. The data was analyzed using phenomenal analysis suggested by Giorgi. As a result, meaningful technologies abstracted from original data were 217, and based on these we induced 26 themes by grouping them with more abstract and integrated language and seven central meanings were induced herein again. Seven central meanings are about stigma of family members of mental illness patients and they are as follows: 'Improper dealing, loss of relationship with surrounding persons, oneself cannot be revealed, conflict with others, unbearable sympathy, incapacity of oneself, buck-passing of oneself'. This study could be a scientific base data to the development of efficient nursing intervention and to understand the pains of mental illness patients and their family members who inevitably have to be separated from the society by recognizing the meaning of stigma to them.

• Journal of Korean Library and Information Science Society
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• v.1
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• pp.69-87
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• 1974

As a part of the status report of all the libraries of Gyeong Buk Province, the libraries of the higher educational institutions in the province were first examined in this study. The following methods were employed for this investigation: 1) questionnaires were sent to the libraries to gather necessary data and 2) the library standards as set by the government were applied for the analysis of the data and other related statistical studies and reports were consulted. Eighteen libraries in the 22 higher educational institutions in the province were examined as of August 1974. For the convenience of the study, the 18 libraries were classified into the following four categories: four-year college library, two-year normal school library, two-year junior college library, and three-year nursing school library. Paul Buck contends that the library is the center of academic life and that the quality higher education is not possible without a quality library. This is so because all the research activities have to be supported by good library facilities. Moreover it is difficult to justify the raison d'etre of an academic community if there is no active research activities in it. If the proposition is accepted that the library plays one of the most important roles in research and that research is one of the most important aspects of an academic community, it cannot be helped but observe that the role the libraries in the province play today is irregular and is far from the educational ideals the higher educational institutions envisage. The present study revealed that there was not a single library in the province which could truly support the research and classroom activities of the higher educational institutions. The college and the normal school libraries, nonetheless, had some facilities to be analyzed. The nursing school and the junior college libraries unfortunately had virtually nothing. It is hoped on the basis of the present study that the libraries should reorganize themselves and look for new directions for active support of research activities.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.522-528
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• 2014

A UHF/VHF full-duplex communication using monopole and dipole antenna has been widely used for cube satellite applications. This kind of communication system requires a dedicated structure panel for antenna integration, which is the one of the disadvantages of the conventional communication system from the accommodation point of view considering the extremely limited volume of the cube satellite. In this study, to maximize the accommodation efficiency of the cube satellite, the commercial UHF half-duplex antenna combined with buck converter for communication modes transition has been considered in the communication system design. Its effectiveness has been verified through link budget analysis based on the antenna specifications and satellite's operation conditions. In addition, the antenna deployment mechanism for the synchronous release of multi-antennas has also been introduced.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.1
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• pp.45-53
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• 2013

Fuel cell power system is one of the most promising energy source for the alternative energy because it has unique advantages such as high energy density, no power drop during operation, and feasible to make compact size. However, due to very low response time, fuel cell is difficult to correspond to drastic load changes and start-up operation. For solving these problem, fuel cell power system must include energy storage device such as Li-Poly battery or super capacitor. Therefore, bi-directional DC-DC converter must be required for this storage device and fuel cell-PCS control. This paper presents a design and modeling of the bi-directional DC/DC converter. Firstly, we present modeling the boost and buck mode of the bi-directional converter through both PWM switch model and state space averaging technique. Secondly, in order to minimize output ripple and transient response overshoot, we have two identical DC-DC converters interleaved and adopt two-loop voltage-current controller. The proposed bi-directional DC-DC converter's modeling method and control design have been verified with computer simulation and experimentation.

• Korean journal of food and cookery science
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• v.8 no.3
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• pp.291-296
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• 1992

The physicochernical properties of Korean buckwheat starches were investigated. The results were as follows; 1. Water binding capacity of kangwon hull buckwheat starch was 106.55% and that of Kangwon rice buckwheat was 99.35%. 2. The pattern of change in swelling power of hull buckwheat starch for increasing temperature started to increase at 60$^{\circ}C$ and increased rapidly from 80$^{\circ}C$, and that of rice buckwheat increased slowly from 60$^{\circ}C$ to 90$^{\circ}C$. 3. The ranges of gelatinization temp. of hull buckwheat and rice buckwheat starches were 70~75$^{\circ}C$ and 75~85$^{\circ}C$, respectively. 4. The blue value of hull buckwheat starch and rice buckwheat starch were 6.25 and 0.62, respectively. 5. The alkali number of hull buckwheat starch and rice buckwheat starch were 1.28 and 3.68 respectively. 6. The amylose content of hull buckwheat and rice buckwheat starch were 32.26% and 38.09%. 7. Periodate oxidation of hull buckwheat starch resulted that amylose had me average molecular weight of 103, 004, degree of polymerizatlon of 572 and amylopectin had me degree of branching of 7.64, glucose unit per segment of 13.09, and periodate oxidation of rice buck wheat starch resulted mat amylose had me average molecular weight of 125, 654, degree of polymerization of 698 and amylopectin had degree of branching of 6.59, glucose unit per segment of 15.16.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.475-479
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• 1987

This survey was conducted to Investigate the NaCl contents of meals taken from common restaurants in Seoul area and further to estimate the total dietary intake of salt from the meals. The samples included Seoleung-tang (beef and rice soup)/Galbitang (beef-rib soup), Yeukkye-jang (spicy beef soup), Doenjangchigye-bab (boiled rice with soy paste stew), Bibim-bab (boiled rice with assorted mixtures) and Bibim-naengmyon (buck wheat vermicelli with assorted mixtures). The average content of NaCl for each sample was determined by saltmeter and its daily intake level was estimated. Doenjangchigye-bab was shown the highest concentration of NaCl Doen-jangchigye-bab was separated into drained residue and fluid, and the average NaCl content in the fluid was higher than that in the residue. In comparision of northern and southern region of Seoul divided by Han river, there was no significant difference in the content of NaCl. The average content of NaCl per meal was 10.6g, and from these data, the daily dietary intake of salt for adults was estimated to be 28.5g.

• Restorative Dentistry and Endodontics
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• v.24 no.3
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• pp.482-489
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• 1999

The purpose of this study was to compare sealing ability between lateral condensation and continuous wave of condensation in depend of root canal curvature. In this study, we divided fifty-six human molar teeth into two group in depend of Schneider method, and then subdivided them into four experimental group (each group is composed of twelve teeth) by canal curvature and obturation method, and eight teeth were served as positive and negative controls. Specimens were prepared by Quantac 2000 series file and obturated by lateral condensation or System B. Specimens were immersed in india ink for 7 days, decalcified by 10% nitric acid, dehydrated by 75, 95 and 100% alcohol in order, cleared by methyl salicylate and then measured of dye penetration with stereomicroscope(${\times}6.5$ magnification) and Image Pro plus. The data were analyzed stastically by one-way ANOVA and Scheffe test. The data were as follows: 1. The mean leakage was $0.725{\pm}1.167$ for group A, $0.813{\pm}0.921$ for group B, $0.809{\pm}0.997$ for group C, $1.111{\pm}1.147$ for group D, but no significant difference among them(p>0.05). 2. Lateral condensation had better sealing ability than continuous wave of condensation, but no significant difference among them(p>0.05). 3. There was no significant difference between root canal curvature degree and microleakage(p>0.05).

• Journal of Power Electronics
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• v.16 no.6
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• pp.2035-2044
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• 2016

In order to match the voltages between high voltage battery stacks and low voltage super-capacitors with a high conversion efficiency in hybrid energy sources electric vehicles (HESEVs), a high ratio bidirectional DC-DC converter with a synchronous rectification H-Bridge is proposed in this paper. The principles of high ratio step-down and step-up operations are analyzed. In terms of the bidirectional characteristic of the H-Bridge, the bidirectional synchronous rectification (SR) operation is presented without any extra hardware. Then the SR power switches can achieve zero voltage switching (ZVS) turn-on and turn-off during dead time, and the power conversion efficiency is improved compared to that of the diode rectification (DR) operation, as well as the utilization of power switches. Experimental results show that the proposed converter can operate bidirectionally in the wide ratio range of 3~10, when the low voltage continuously varies between 15V and 50V. The maximum efficiencies are 94.1% in the Buck mode, and 93.6% in the Boost mode. In addition, the corresponding largest efficiency variations between SR and DR operations are 4.8% and 3.4%. This converter is suitable for use as a power interface between the battery stacks and super-capacitors in HESEVs.