• Journal of Advanced Marine Engineering and Technology
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• v.18 no.5
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• pp.12-23
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• 1994

The two-phase flow is observed in power plants, chemical process plants, and refrigeration systems etc., and it is very important to solve the heat transfer mechanism of a boiler, an automic reactor, a condenser and various types of evaporators. Recently, the problem of two phase heat transfer is braught up in many regions with development of energy saving technique. In flow boiling system it is necessary to store data in each condition because the heat transfer characteristics of flow boiling region vary by the change of flow pattern and the magnetude of heat flux to tube length, and be subtly affected by the flow and heating condition. So basic study for knowing flow pattern in heat transfer region and the relation between heat transfer characteristic and flow condition is desired to accumulate data in wide variety of liquid and flow system in the study of heat transfer of two phase flow. In this study R-113 was selected as working fluid whose properties were programmed by least square method, and experiment was conducted in the region of mass flow $1.628{\times}10^6$~$4.884{\times}10^6$/kg/$m^2$hr with inlet subcooling 10~3$0^{\circ}C$, sustaining test section inlet pressure to 1.5kg$_f$/$cm^2$abs.

• Journal of Biosystems Engineering
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• v.21 no.4
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• pp.429-435
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• 1996

A wind tunnel consisting of two air flow conditioners with polycarbonate pipes, a plant growth room, a suction fan and fan controller, and fluorescent lamps, was designed to investigate the interactions between the growth of plug seedlings under artificial light and their Physical environments. Light transmissivities in the plant growth room based on the photosynthetic photon flux density and photosynthetically active radiation was appeared to be 96.3% and 96.8%, respectively. Measurement showed a uniformity in the vertical profiles of air current speed at the middle and rear regions of plug trays in wind tunnel. This result indicated that the development of a wind tunnel based on the design criteria of the American Society of Mechanical Engineers was adequate. Air current speed inside the plug stand was significantly decreased due to the resistance by the leaves of plug seedlings and boundary layer developed over and below the plug stand. Driving force to facilitate the diffusion of gas inside the plug stand might be regarded as extremely low. Aerodynamic characteristics above the plug stand under artificial light were investigated. As the air current speed increased, zero plane displacement decreased but roughness length and frictional velocity increased. Zero plane displacement linearly increased with the average height of plug seedlings. The wind tunnel developed in this study would be useful to investigate the effects of air current speed on the microclimate over and inside the plug stand and to collect basic data for a large-scale plug production under artificial light in a semi-closed ecosystem.

• Proceedings of the Botanical Society of Korea Conference
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• 1995.07a
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• pp.57-86
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• 1995

Molecular mapping of plant genomes has progressed rapidly since Bostein et al.(1980) introduced the idea of constructing linkage maps of human genome based on restriction fragment length polymorphism (RFLP) markers. In recent years, the development of protein and DNA markers has stimulated interest for the new approaches to plant improvement. While classical maps based on morphological mutant markers have provided important insights into the plant genetics and cytology, the molecular maps based on molecular markers have a number of inherent advatages over classical genetic maps for the applications in genetic studies and/or breeding schemes. Isozymes and DNA markers are numerous, discrete, non-deleterious, codominant, and almost entirely free of environmental and epistatic interactions. For these reasons, they are widely used in constructing detailed linkage maps in a number of plant species. Plant breeders improve crops by selecting plants with desirable phenotypes. However a plant's phenotyes is often under genetic control, positioning at different "quantitative trait loci" (QTLs) together with environmental effects. Molecular maps provide a possible way to determine the effect of the individual gene that combines to produce a quantitative trait because the segregation of a large number of markers can be followed in a single genetic cross. Using market-assisted selection, plants that contain several favorable genes for the trait and do not contain unfavourable segments can be obtained during early breeding processes. Providing molecular maps are available, valuable data relevant to the taxonomic relationships and chromosome evolution can be accumulated by comparative mapping and also the structural relationships between linkage map and physical map can be identified by cDNA sequencing. After constructing high density maps, it will be possible to clone genes, whose products are unknown, such as semidwarf and disease resistance genes. However, much attention has to be paid to level-up the basic knowledge of genetics, physiology, biochemistry, plant pathology, entomology, microbiology, and so on. It must also be kept in mind that scientists in various fields will have to make another take off by intensive cooperation together for early integration and utilization of these newly emerging high-techs in practical breeding. breeding.

• Journal of Korean Public Health Nursing
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• v.8 no.1
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• pp.63-72
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• 1994

The purpose of this study was to estimate the industrial worker's knowledge, attitude, and practice about occupational health and to provide the basic data for the development of industrial health services. The study was undertaken from January 15 to January 30, 1993. 549 industrial workers at the Industrial Complex located in Chonbuk Province were participated in this study. The results were as follows; 1. The Knowledge, Attitude and Practice leveles of Workers about Occupational Health. The levels were measured by five point scale. The mean score of knowledge was 2. 59 point out of 4. The mean score of attitude was 2.37 point out of 4. The mean score of practice was 2. 38 point out of 4. 2. The analysis of their knowledge" attitude, and practice about general characteristics. 1) There was significant difference among different age groups. $(P{\leqq}0.0001)$ -. The group of age 25-29 was the highest value in knowledge and attitude. -. The group of age over 50 was highest value in practice. 2) There was significant difference between sexual groups in all items. -. Male workers were higher than Female workers in all items. (P=0.0000) 3) There was significant difference according to the marital status in all items. -. Married workers were higher than Single workers in all items. (P = 0.0000) 4) There was significant difference among different groups of educational level in attitude and practice. (P<0.05) The value was positivly correlated to their educational level. 5) There was significant difference among the groups of job-part in knowledge and practice. (P=0.000, P=0.031) -. Office workers were higher than Production workers in all items. 6) There was significant difference among different group of job experience in knowledge and attitude. (P=0.0000. P=0.0387) The value was positively correlated to the years length of job experience. 7) There was significant difference among the groups of different monthly income in all items. (P=0.000) The value was positively correlated to their monthly income.

• Journal of Mushroom
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• v.12 no.3
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• pp.145-153
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• 2014

Pleurotus has increased rapidly production and consumption because of highly nutritional value, natural healthy food and so on. The basic studies for Pleurotus need for development of mushroom industry. This study was to investigate the cultural characteristics among 15 strains of 6 species and to analyze their phylogenetic relationships. The cultural characteristics were investigated by mycelial growth activity at different media, temperature and pH. The optimum media for mycelial growth were YM and MCM in most species. The optimum temperature for mycelial growth were $25^{\circ}C$ and $30^{\circ}C$. The optimum pH for mycelial growth were widly range from pH 5.1 to 7.4. Through the RFLP (restriction fragment length polymorphism) of IGS (intergenic spacer) I region in ribosomal DNA, it was analyzed phylogeny of interspecies and intraspecies. Each species was discriminated well as isolates within each species formed clade to be distinguished other species. P. florida was highly similar to P. floridanus, and P. flabellatus was P. cornucopiae. P. fuscus var. ferulae was highly similar to P. eryngii but discriminated different species in analysis of RFLP of IGS I region and showed different characteristics in mycelial culture. RFLP of IGS I region was useful of studying phylogenetic relationships of species and population.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.511-518
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• 2017

In recent years, many interests and researches on the insulations required the multiple performances other than insulation performance. The purpose of this paper is to find the optimal ratio between wood fiber and rice-husks charcoal to develop a structural board with carbonized rice-husks. Based on these rice-husks charcoals, basic research was carried out to develop thermal insulation materials with structural performance, and the following conclusions were obtained. The MC of the board using the carbonized rice-husks was 3.2-4.1% and the density was 0.58-0.68, indicating the possibility of excellent structural material. The bending strength was 9.1-32.6 MPa in the length direction and 9.2-34.1 MPa in the width direction. It is possible to obtain the bending strength of the normally used MDF level and to find the possibility of development of the thermal insulation material having the structural performances.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.11-16
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• 2011

This study was conducted to identify the morphological characteristics and variations level by site environment of native bermudagrass (Cynodon spp.) from costal and island region in South Korea. Soil chemical properties and morphological characteristics were investigated. There were significant differences in plant height, leaf width, leaf length, cotton on leaf blade, stolon, and number of seed per spike depending on where they were collected from natural habitat. We have discovered a variety of variation among the investigated traits in Korean native bermudagrass ecotypes. There were broad leaf and fine leaf types of native bermudgarass in S. Korea. Adaptability was in very high on inadequate environment in bermudagrass with broad leaf types, it has also been suggested that management worth in terms of use. These results may provide basic information for bermudagrass breeding development and the collected types during this investigation would be worth being preserved as genetic resources for further breeding purposes.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.437-443
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• 2019

Aid to navigation is a navigational aid facility that informs a sailing vessel of its location and direction as well as a location of a specific obstacle by means of a light, shape, color, sound, radio wave, etc. It can be valuable in improving the safety of day and night vessel navigation at sea. For the safety of the tug boat, the minimum equipment requirements for each type of tug boat are arranged. Despite these preparations, the collision accidents between tug boats, barges, and light buoys can occur when the tug boat turns due to the length of the tow-line, tidal current, and the barge's momentum etc. The purpose of this study was to propose the basic system that analyzes the physical relationship between two vessels regarding the tug boat-barge-light buoy dynamics and propagate the corresponding data through the aid to navigation management & operation systems in use at each regional oceans and fisheries.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1791-1795
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• 2013

Aims and Background: Prostate cancer is one of the most common malignant tumors in the male reproductive system, which causes the second most cancer deaths of males, and control of angiogenesis in prostate lesions is of obvious importance. This study assessed the effect of apogossypolone (ApoG2) on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs). Subjects and Methods: HUVECs were treated with different concentrations of ApoG2. The survival rate of HUVECs were determined by MTT assay. Utrastructural changes of HUVECs were assessed with transmission electron microscopy. Apoptosis in HUVECs was analyzed by flow cytometry and cell migration by Boyden chamber assay. Matrigel assays were used to quantify the development of tube-like networks. Results: ApoG2 significantly inhibited HUVEC growth even at 24 h (P<0.05). The inhibitory effect of ApoG2 is more obvious as the concentration and the culture time increased (P<0.05). These results indicate that ApoG2 inhibits the proliferation of HUVECs in a time- and concentration-dependent manner with increase of the apoptosis rate. Besides, ApoG2 reduced the formation of total pseudotubule length and network branches of HUVECs. Conclusions: The results suggest that ApoG2 inhibits angiogenesis of HUVECs by growth inhibition and apoptosis induction.

• The International Journal of Costume Culture
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• v.3 no.1
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• pp.1-11
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• 2000

The purpose of this study is to compare the constitutions comparatively among Korean, Chinese and Chosunjok college women and thereby, provide for some basic data helpful to the development of export apparels befitting the Chinese consumers, For this purpose, Korean, Chinese and Chosunjok college women aged between 17 and 24 were sampled to be subject to body measurements. The measurement data obtained were indexed for each part of the body to set a total 29 constitutional indices, which were analyzed by factor dictating the major shapes of body, Thus, based on the constructed, the differences of constitution among three groups were comparatively analyzed. The results of this study of this study can be summarized as follows; It was found through this study that Korean college women had thickest neck compared with body size and had longer lower limbs compared with stature, Moreover, their lower body was absolutely longer than the other two groups, and thus, Korean college women were found slimmest. On the other hand, Chinese college women had most voluminous chest turned over with shorter and thicker body. they were obesest. Chosunjok college women had longest upper body but shortest breast length. Their lower body was obesest, and their body was longer compared with stature. Moreover, Chosunjok college women's lower limbs were shortest, while their arm scyes were small nearest body type.