• Journal of the Korean Geographical Society
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• v.28 no.1
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• pp.40-57
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• 1993

This paper aims to show the various aspects of migration in Kwangju merropolitan area, southwestern Korea, for a period of years 1980-1985. Migratory patterns are spatially extensive in countryside around Kwanfju, and due to high accessibility to the metropolitan area urban implosion emerges in the city. In Chonnam province where Kwangju is loca-ted, all cities and counties except for such in-dustrial areas as Yochon, and Kwangyang are experiencing population losses in terms of net migration by survival rate methods. Kwangju is the exceptionally one of in-migration areas in Chonnam, though its central part(Dong-Gu) is also an out-migrated area. Predominantly in-migration urban areas have high proportions of a student age group between 15-19 years, and that reflects the importance of the educational factor in migration analysis. The municipal authorities of Kwangju are planning to block the way of the middle sxhool students who live in the outskirts of Kwangju to entrance to high school in the city. Thant may stir up migrations into Kwangju for the elementary and middle school students, because the city id expected to provide educational opportunities higher and better than remaining Chonnam areas. Population of Kwangju would, therefore, grow as the students migrate into the city. The findings on the residential intra-city movement in selected 5 Dongs indicate that implications of a short-distance movement re noteworthy; neighbour to neighbour, and the nearest stop in the way from the outer Kwangju as well. Trends in a short-distance movement are in accord with Ravensteins's "law of migra-tion". But in casw of the inter-provincial migra-tion to Kwangju, the number of in-migrants from remoter Seoul is more than that from nearer Chonbuk province. Therefore it supports the fact that the movement between capital region and far off local cities overcomes a distance barrier. The temporary mobility for a day has been increased as the standard of living has improved and it reaches a peak on weekend or on con-secutive holidays. The number of temporal movers to Kwangju from capital region and Yongnam area, southeastern Korea has a greatincrease in terms of the frequency of the passengers' mobility, in particular on Myongjol(the ethnic and traditional festival day) in com-parison with on weekdays. By comparison with two largest Myongjols, the number of movers is more on Chusok(The Full Moon festival on lunar August) than on Sol (lunar new year's day). Annual peak point of weekday movers appears in August because of summer vacation. But the lowest one appears in June, which is related to the busy farming season. A patients' move for medical services in on the increase with a change of living conditions. It is especially true in the industrial counties such as Kwangyang and Yochon. By way of conclusion, it should be pointed out that one of the problems we face in survey of migration volume by the survival rate method is that the survival rate somtimes exceeds the value 1.0, in normal states of which should be under 1.0. it may be due to the shortcoming from the census statistics. We should not give therefore too much stress on the importance of migrations or moves as an element of changes in spatial pattern. In cinclusion, the results of the study show some geographic facts as the followings: 1. One of the outstanding phenomena in all types of movement is the seletivity of ages. The most important factors are related to education and employment. 2. Short-distance movement is carried out in accordance with Ravenstein's law, but in case long-distance movement, in-migration from capital region is prominent in spite of remoten-ces. The gravity between large cities such as Kwangju and Seoul, which has a frequent human movenent, causes urban implosion of small cities between those cities. 3. The temporary mobility for a day, in con-trast to that of permanent movement, is more related to transportation, and its volumes and annual variations are a large-scale. 4. Passengers' mobility is high in industrial cities. And the scope of patients' mobility is narrower than passengers'.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.202-208
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• 2006

An experiment was conducted to investigate the effects of three water temperatures (15, 20 and $25^{\circ}C$) in combination with three salinities (0, 15 and 30 psu) on the oxygen consumption rate of juvenile spotted sea bass, Lateolabrax maculatus (mean body weight $5.5{\pm}0.3g$). The oxygen consumption rates of L. maculatus were measured in triplicate for 24 hours using a continuous flow-through respirometer. Water temperature resulted in significant differences in the mean oxygen consumption rate of L. maculatus (p<0.001), but salinity and combinations of salinity and water temperature did not have (p>0.05). The oxygen consumption increased with increasing water temperatures in all experimental salinity regimes (p<001). Mean oxygen consumption rates at 15, 20 and $25^{\circ}C$ ranged 328.8~342.3, 433.9~441.0 and 651.5~659.9 mg $O_2\;kg^{-1}\;h^{-1}$, respectively. $Q_{10}$ values did not vary with salinity, bud varied with water temperature. $Q_{10}$ values ranged 1.63~1.75 between 15 and $20^{\circ}C$, 2.24~2.26 between 20 and $25^{\circ}C$, and 1.92~1.98 over the full temperature range. The energy loss by metabolic cost increased with increasing water temperatures in all experimental salinity regimes (p<0.001) Mean energy loss rates at 15, 20 and $25^{\circ}C$ ranged 224.6~233.8, 296.3~301.2 and $444.9{\sim}450.7kJ\;kg^{-1}\;d^{-1}$, respectively. These data suggest that the culture of juvenile spotted sea bass is possible without energy loss by salinity difference in freshwater as well as seawater after salinity acclimation. Thus, this result has an application for culture management and bioenergetic model for growth of this species.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.118-131
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• 2019

In order to provide 8K UHD contents of terrestrial broadcasting with a large capacity, the terrestrial broadcasting system has various problems such as limited bandwidth and so on. To solve these problems, UHD contents transmission technology has been actively studied, and an 8K UHD broadcasting system using terrestrial broadcasting network and communication network has been proposed. The proposed technique is to solve the limited bandwidth problem of terrestrial broadcasting network by segmenting 8K UHD contents and transmitting them to heterogeneous networks through hierarchical separation. Through the terrestrial broadcasting network, the base layer corresponding to FHD and the additional enhancement layer data for 4K UHD are transmitted, and the additional enhancement layer data corresponding to 8K UHD is transmitted through the communication network. When 8K UHD contents are provided in such a way, user can receive up to 4K UHD broadcasting by terrestrial channels, and also can receive up to 8K UHD additional communication networks. However, in order to transmit the 4K UHD contents within the allocated bit rate of the domestic terrestrial UHD broadcasting, the compression rate is increased, so a certain level of image deterioration occurs inevitably. Due to the nature of UHD contents, video quality should be considered as a top priority over other factors, so that video quality should be guaranteed even within a limited bit rate. This requires packet scheduling of content generators in the broadcasting system. Since the multiplexer sends out the packets received from the content generator in order, it is very important to make the transmission time and the transmission rate of the process from the content generator to the multiplexer constant and accurate. Therefore, we propose a variable transmission scheduler between the content generator and the multiplexer to guarantee the image quality of a certain level of UHD contents in this paper.

• Korean Journal of Agricultural Science
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• v.1 no.1
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• pp.91-116
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• 1974

Taiwan agricultural development in the last decade has not been changed much since the accomplishment of land reform program. This is mainly due to the rapid development taken place within industry that agricultural development can not keep pace with. The increasing gap of rural-urban income discrepancy has caused socio-psychological unstability among rural people and inspire wants of out-migration. From 1961 to 1970, population of the ten largest cities showed an annual growth rate of 4.05%, while the population of the remainder of Taiwan showed 2.06%. Assuming the natural increase rate of these two population sections are similar, the difference of rural and urban annual growth rate can be at tributed to the flow of people from rural to urban sectors. The main objective of this paper is to identify the amount of agricultural out-migration and its impact on agricultural development and agricultural extension programs. Specifically, the objectives are to examine (1) rural-urban population composition (2) rural out-migration estimation (3) changes of agricultural population, and (4) implications for agricultural development and extension programs Some of the important findings are listed below; (1) The average agricultural out migration of the period 1960-1969 is estimated at around 60,000 per year. Take Tainan prefecture for example, the Male-Female Migration Ratio is 0.39 for age 20-24, 0.55 for age 25-29, 0.90 for 30-34. It is understood between age 20 and 34, the rural female migration rate is higher than the rural male. (2) Based on the population growth rate of 1950-1969, agricultural population is projected for the period of 1953 to 1989. By 1978, the agricultural population will reach its peak and begin to dedaine from 1980. The projected agricultural population in 1989 is 5,847,566 which occupies 29% of the Taiwan total population. (3) Assuming area of cultivated land keep unchanged as 905,263 ha. in 1970, and tif we can eliminate all 72% of part-time farms, then the average farm acreage for hose full-time farms will be increased to 3.6 hactares. This is unlikely to happen before 1989 without the government interference. (4) Less than 10% of adult farmer s of age 25-64 in 1969 enrolled in Farm Discussion Club, only 5% of adult farm women enrolled in Home Economics Club, and 5% of rural youth enrolled in 4-H Club. These statistics show a fact that only few farmers are reached by extension workers. Based on findings in this paper, some important suggestions are listed for future agricultural development. (1) Improve agricultural structure by decreasing agricultural population (a) Encourage farmers with less than 0.5 ha. of land to seek jobs outside of agriculture (b) Encourage joint cultivation and farm mechanization (c) Discourage rural migrants to Keep farm land (d) Provide occupational guidance program through extension education programs (2) Establish future farmers settlement project to assure rural youth have enough resources for farming. (3) An optimum Population policy should be integrated into rural socio-economic development and national development programs.

• Asian Journal of Turfgrass Science
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• v.21 no.1
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• pp.9-21
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• 2007

Research was initiated to examine establishment efficiency of zoysiagrass by plugging. Zoysiagrass is known to be a slowly establishing turfgrass species. Properly-treated zoysiagrass seed can speed up the establishment rate, while initial irrigation practice is intensively required after seeding. A planting method with small plugs($2.5{\times}2.5cm$) from seeding can overcome initial watering requirement. Establishment speed, however, can vary with planting dates, planting spaces, and plastic film cover in early stage. Establishment characteristics were investigated for two years by planting dates that were April 5, May 18, July 13, August 24 and October 29 in 2004 and April 6 in 2005. They were also compared with three different spaces($20{\times}20,\;25{\times}25,\;and\;30{\times}30cm$) and three different fertilizer levels(15, 30, and $45g\;N{\cdot}m^{-2}$). Ground coverage reached to 90% in plugs of 'Zenith' zoysiagrass planted on April 5. It increased suddenly in period of July to August, resulting in about 50% of full establishment rate. Establishment rates were significantly faster over 9% in plugs spaced at $20{\times}25cm$ than in those at $30{\times}30cm$. No significant differences were observed on the stolen number and stolen length in the study. Survival rate in zoysiagrass plug was over 90% at all plantings. These results demonstrated that zoysiagrass establishment using small plug from seeding is considered to be a safe and efficient method.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.23-32
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• 2011

Design and Implementation of Clipcast Service via Terrestrial DMB This paper outlines the system design and the implementation process of clipcast service that can send clips of video, mp3, text, images, etc. to terrestrial DMB terminals. To provide clipcast service in terrestrial DMB, a separate data channel needs to be allocated and this requires changes in the existing bandwidth allocation. Clipcast contents can be sent after midnight at around 3 to 4 AM, when terrestrial DMB viewship is low. If the video service bit rate is lowered to 352 Kbps and the TPEG service band is fully used, then 320 Kbps bit rate can be allocated to clipcast. To enable clipcast service, the terminals' DMB program must be executed, and this can be done through SMS and EPG. Clipcast service applies MOT protocol to transmit multimedia objects, and transmits twice in carousel format for stable transmission of files. Therefore, 72Mbyte data can be transmitted in one hour, which corresponds to about 20 minutes of full motion video service at 500Kbps data rate. When running the clip transmitted through terrestrial DMB data channel, information regarding the length of each clip is received through communication with the CMS(Content Management Server), then error-free files are displayed. The clips can be provided to the users as preview contents of the complete VOD contents. In order to use the complete content, the user needs to access the URL allocated for that specific content and download the content by completing a billing process. This paper suggests the design and implementation of terrestrial DMB system to provide clipcast service, which enables file download services as provided in MediaFLO, DVB-H, and the other mobile broadcasting systems. Unlike the other mobile broadcasting systems, the proposed system applies more reliable SMS method to activate the DMB terminals for highly stable clipcast service. This allows hybrid, i.e, both SMS and EPG activations of terminals for clipcast services.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.501-510
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• 2015

In this study, we investigated the onset and release of endo-dormancy under natural conditions by observing bud break characteristics in 'Fuji' apple trees using water cuttings. Through examinations of bud break rate and days to bud break, we found that the endo-dormancy of 'Fuji' apple tree continues for 70 d from 165 to 255 d after full bloom (DAFB), from late October to early January of the following year. In addition, within 20 d of first bud break, based on a final bud break rate of 60% or more, we able to identify the timing of the changeover from para-dormancy to endo-dormancy, and endo-dormancy to eco-dormancy. Analysis of the chilling requirement during the endo-dormancy period revealed that chilling accumulation up to 255 DAFB to release endo-dormancy amounted to 666 and 517 h based on the CH and Utah models, respectively. Observation of internal changes in the bud during endo-dormancy showed that flower bud differentiation begins from mid-July, and t ime of inflorescence o f the disk f lower is a vailable to f ind. The f lower buds subsequently developed slowly but steadily during endo-dormancy and in the following year in February, the developmental stage of each organ had progressed. Moreover, the flower buds of 'Fuji' apples were mostly healthy during the dormancy period, but some exhibited necrosis of flower primordium, due partial cell damage from the formation of ice crystals rather than a direct effect of the low temperature. Flower buds were formed in both the axillary buds of bourse shoots and terminal buds of spurs, but lower bud differentiation was observed for the terminal buds of spurs at rate of about 65% of total buds, which was directly related to the bud size and shoot diameter.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.1
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• pp.33-43
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• 2003

The midwater pair trawl which is being used at present in Korea have several problems. Firstly, it is difficult to control the net height on high towing speed. Secondly, net breaking often occurs owing to floats and thirdly, the volume of net on the net drum is so large. This study is aiming for examining the possibility of application for the Korean midwater pair trawl through the model experiment of non-float midwater pair trawl. The model of non-float midwater pair trawl was manufactured as 1/100 of the full scale net which is being used in bottom pair trawl for 850ps class considering the Tauti's Similarity law. The model experiment was carried out to analyze the opening efficiency according to the variation of lower warp length and the opening efficiency was investigated between th proto type and non-float type. The results obtained can be summarized as follows ; 1. The hydrodynamic resistance of non-float type was about 10~20% smaller than that of the proto type and it increased about 1ton according to the increase of dL at the condition of the same flow speed. The resistance acting on the lower warp decreased about 5% but that of the upper warp increased according to the increase of lower warp length (dL) at the condition of the same flow speed. 2. The net height of the non-float type decreased almost linearly according as the increased of flow speed and it increased in a logarithmic functional form with the increase of the lower warp length at the condition of the same flow speed. On the decreasing rate of the net height, the non-float type was lower than the proto type and the difference of the decreasing rate was about 12% at 3.0 knot, 25% at 4.0 knot, 25% at 4.0 knot respectively when dL was 30m. 3. The net width of non-float type was not varied so much as only 2m range and was larger than that of proto type. 4. The mouth area of non-float type decreased in a exponential functional form. On the decreasing rate of the mouth area, the non-float type was lower than the proto type. The filtering volume increased in a logarithmic functional form with increasing flow speed and the filtering volume of proto type decreased steeply over 3.0knot, but that of non-float type increased until 4.0knot. 5. The optimal length of lower warp was when the value of dL was about 30m and the optimal position of front weight was at the connection point of four net pendants.

• Korean Journal of Occupational Health Nursing
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• v.4
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• pp.5-29
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• 1995

Occupational health services in Korea have been operated as dual types : one is operated by occupational health care manager and the other is health care agency without their own personnel. The performance of occupational health service should be different due to the variety of characteristics of health care manager and workplace, qualification of health care manager. This study is to analyze performance of occupational health care services with a particular consideration of job performance shape and efficiency, based on comparing those two types of health care management to show on the basic data for the settlement of more qualitative health care management system at workplace. For this study, total 391 places in Seoul and Inchon city area ; 154 places (39.4%) managed by designated health care manager and 237 places (60.6%) by the agency with their commission are selected as research samples. Tools for data collection are questionnares that have been investigated during the period of 20 September 1993-20 December 1993. Those data are compared with percentiles, mean, standard deviation and B/C ratio using SPSS PC program. Conclusions observed from the tests and each comparison could be summerized as follows : 1. Occupational health care have been accomplished at workplaces with designated people than with agencies people, and coverage rate of the occupational health care services has differences, due to management types. The reason of these results is due to visit only one or two times monthly by the agencies, while their own health care manager obsess, at the workplaces all the times. 2. Most of the expense for environmental control of all health care services expenditures shows that there is almost no fundamental improvement because more expenses are needed for procuring personal protective equipment and measuring work environment instead of environmental improvement. 3. It is investigated how much the cost of occupational health care services needs per worker, and calculated how much the cost needs per service hour per worker. The results from this show that the cost of occupational health services at workplaces with their own managers used less than the cost of health care agencies, eventually the former gives better services with less cost than the latter. 4. Benefit/Cost ratio is also produced by total benefit/total cost. The result from the above way reads 4.57 as a whole, while their own manager having workplaces reads 4.82 and the agencies do l.56. Even if their own manager performing workplaces spent more cost, this system produces more benefit than the agencies management. 5. The B/C ratio for medical organization such as local clinic, health care center and pharmacy shows more than or equal to at the workplaces controlled by the agencies. It is inferred that benefit would be much less than the cost used, with so being inefficient. 6. It is assumed that the efficiency ratio of health education is equal to reduction rate of workers medical organization visit. Estimated reduction rate 5%, 10%, 15%, show that the efficiency ratio of health education have an effect on producing benefits. It is estimated that more benefit can be produced if more qualitative education will be provided for enhancing health care efficiency. 7. Results of this study cannot be generalized because there are large scale of deviation in case of workplaces with less than 300 full time workers, but B/C ratio reads 2.69 as a whole and 3.25 at workplaces with their own health care manager are higher than 1.63 at the workplaces manged by the agencies. Finally, all the benefit concerning health care services could not be quantified, measured and shown on the value of money. This is a reason that a considerable part of benefits are so underestimated. This is also thought that measurement tools should be developed for measuring benefits of health care services with a comprehensive quantification. in the future. It is also expected that efficiency of occupational health care services should be investigated using cost-effectiveness analysis.

• Korean Journal of Social Welfare
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• v.60 no.3
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• pp.31-58
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• 2008

This study examines applying the elderly poverty labor hypothesis and skill-biased technological change hypothesis to labor force participation rate(LFPR) of older males in Korea. These hypotheses have hardly been examined on the this group. The analysis is based on the data "Summary of economically active population($1965{\sim}2007$)", "Population projection($1965{\sim}2007$)", "Report on wage structure survey($1993{\sim}2005$)" and "Korea Labor and Income Panel Study($1998{\sim}2006$)". The method employed for this study is logistic regression. The main results from this analysis are summarized in five points. Firstly, Korean older males' LFPR have been increasing since 1965 when industrialization was expanding at full steam. This trend has been different from the decreasing trend of industrialized countries. The second finding is that poor older males' LFPR is, on the average, 5.2% higher than that of non-poor older males from 1998 to 2005. The third result is that the non-elderly man has been increasingly positioned at higher grade occupations, while the elderly man has been held at lower grade occupations. The fourth is that labor demand for highly educated workers has exceeded the increased labor supply of the group, while the demand for low educated workers has decreased far beyond the declined labor supply. As a result, college premium has increased from 139% in 1993 to 157.8% in 2005. The final main implication of this study is that the industrialization theory and modernization hypothesis still holds for the LFPR of Korean older males. However, the elderly affluence hypothesis of the LFPR of older males are hardly persuasive in explaining Korean phenomenon. Especially, we find that the elderly poverty is the main mechanism in determining the Korean LFPR in old ages. This supports the elderly poverty labor hypothesis presented in this study. Skill-biased technological change hypothesis partially explains the LFPR of older man. However, we believe that other factors; human capital specially high school education rather than university education and skill required in less skill biased occupations or the poverty; also have taken effect.