• Title/Summary/Keyword: Construction Labor

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Characteristics of Labor Market and Spatial Networks in Daedeok Science Town as Locality, Korea (로캘러티로서 대덕연구단지의 노동시장 특성과 공간적 네트워크)

  • Han, Ju-Seong
    • Journal of the Korean association of regional geographers
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    • v.7 no.2
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    • pp.35-54
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    • 2001
  • The construction of Daedeok Science Town, located in Yuseong ward of Daejeon metropolitan city, began in the early 1970s. It started out as a national project to form an agglomeration of the major central government research institutions. Since that time Daedeok Science Town has also attracted private research institutions, mainly during the 1900s. This study geographically analyzes this research institutions to clarify the regional identity of Daedeok Science Town through an integrated approach of existing new regional geography approach, which is characteristics of labour market as the regional pattern of its laborers' residences, spatial labour division, its research network with other institutions, and networks of university, research institution, and corporations, through the spatial spread of intellectual right of property and through network of technology business incubator relationship with spin offs which is appeared to spatial interaction. The results of the study are as follows: First of all, Daedeok Science Town was not only self-sustenance with marketing garden of agricultural regions in the suburb of Daejeon city but also was consign of agricultural products to Daejeon city before 1972. Since that time, the identity of Daedeok Science town has been formed by externally factors of the science development, by the local decentralization of population and public offices in Seoul metropolitan area in terms of the world economy system, and by the internally accessibility maximization of the central location in Korea between 1992 and 1999. On the part of Daedeok Science Town it has some merits of in-migration from nation-wide, and of mother city's Daejeon. Lastly at the period of the venture business beginning after 1999, the role of institution, developing the existing high technology, made great contribution to an attraction of ventures business to here in need of high technology industry growth, including knowledge-based industry in the informated society. On these bases, Daedeok Science Town seems to grow spontaneously as a science park.

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Recent Progress in Biotechnology-based Gene Manipulating Systems to Produce Knock-In/Out Mouse Models

  • Lee, Woon Kyu;Park, Joong Jean;Cha, Seok Ho;Yun, Cheol-Heui
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.5
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    • pp.745-753
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    • 2008
  • Gene-manipulated mice were discovered for the first time about a quarter century ago. Since then, numerous sophisticated technologies have been developed and applied to answer key questions about the fundamental roles of the genes of interest. Functional genomics can be characterized into gain-of-function and loss-of-function, which are called transgenic and knock-out studies, respectively. To make transgenic mice, the most widely used technique is the microinjection of transgene-containing vectors into the embryonic pronucleus. However, there are critical drawbacks: namely position effects, integration of unknown copies of a foreign gene, and instability of the foreign DNA within the host genome. To overcome these problems, the ROSA26 locus was used for the knock-in site of a transgene. Usage of this locus is discussed for the gain of function study as well as for several brilliant approaches such as conditional/inducible transgenic system, reproducible/inducible knockdown system, specific cell ablation by Cre-mediated expression of DTA, Cre-ERTM mice as a useful tool for temporal gene regulation, MORE mice as a germ line delete and site specific recombinase system. Techniques to make null mutant mice include complicated steps: vector design and construction, colony selection of embryonic stem (ES) cells, production of chimera mice, confirmation of germ line transmission, and so forth. It is tedious and labor intensive work and difficult to approach. Thus, it is not readily accessible by most researchers. In order to overcome such limitations, technical breakthroughs such as reporter knock-in and gene knock-out system, production of homozygous mutant ES cells from a single targeting vector, and production of mutant mice from tetraploid embryos are developed. With these upcoming progresses, it is important to consider how we could develop these systems further and expand to other animal models such as pigs and monkeys that have more physiological similarities to humans.

Development of a Precision Seeder for Direct Seeding of Rice on Dry Paddy (정밀 파종 벼 건답직파기 개발)

  • Yoo, S.N.;Kim, D.H.;Choi, Y.S.;Suh, S.R.
    • Journal of Biosystems Engineering
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    • v.33 no.2
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    • pp.83-93
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    • 2008
  • In order to save labor and cost, direct seeding has been considered as an important alternative to the machine transplanting in rice cultivation. Current direct seeding machines for rice in Korea drill irregularly under various operating conditions. This study was conducted to develope a precision seeder which enables the accurate, even-spaced in row placement of rice seeds at uniform depths of 3-4 cm on dry paddy. Design, construction and performance evaluation of the precision seeder were carried out. The tractor rear-mounted type 8-rows precision seeder which performs seeding in addition to fertilizing, ditching, and rotary tilling works on dry paddy was developed. Main components of the seeder were ditcher and leveller, rotary tiller, powered roller type furrow opener, seeding device, powered roller type furrow covering and firming device, hydraulic unit, seeding speed control system, power transmission system, hitch and frame. Ditching, furrow opening, and seed covering and firming performances were good and seeding depths of 2-4 cm could be maintained. Planting accuracies and planting precisions were within 13.6%, and 31.2%, respectively, for planting space of 15 cm, and seeding velocity of 0.5 m/s. These mean variations of average planting space were within 2.1 cm, and 90% of seeds in a hill were seeded within 4.7 cm of hill length, respectively. Error ratios between setting planting space and measured average planting space were shown within 6.7%. Therefore the seeder showed good planting performance up to seeding velocity of 0.5 m/s in field tests. And field capacity of the seeder was about 0.28 ha/hour.

Study on Cooling Characteristics of the Tunnel Type Pressure Pre-Cooling System

  • Lee W. O.;Yun H. S.;Lee K. W.;Jeong H.;Cho K. H.;Cho Y. K.;Lee J. H.
    • Agricultural and Biosystems Engineering
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    • v.4 no.2
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    • pp.58-65
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    • 2003
  • An understanding of the cooling requirements of horticultural commodities begins with adequate knowledge of their biological responses. All fresh horticultural products are living organisms, carrying on the many biological processes that are essential to the maintenance of life. The pre-cooling is essential technique for the construction of cold chain system, which is necessary to maintain marketing quality of fresh produces during the transportation and distribution. The purpose of this study is to develop the pressure cooling tunnel using conveyer for the reduction of labor and improvement of pre-cooling efficiency. Performance of developed facility was tested for the strawberries, tomatoes and Chinese cabbages. Cooling ratio as a result of pre-cooling efficiency was 1.57, 1.56 and 1.32 for strawberries, tomatoes, and Chinese cabbages respectively. Cooling ratio decreased with increasing the distance of heat conduction from surface to center. The cooling ratio of Chinese cabbages was lower than that of fruit because of its head and leaf. In aspect of cooling uniformity, there was no significant difference of final temperature among inlet, outlet and middle layers of cold air in fresh produces. After pre-cooling treatment, quality changes were measured for the weight loss, Vit. C content, and titratable acidity. The quality of pre-cooling treatment was better than that of non-treatment and was kept on well during long-term storage.

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The Development of an End-Effector in Automated Pavement Crack Sealer and Technical Feasibility Analysis (도로면 크랙실링 자동화 장비 말단장치의 요구성능 분석을 통한 설계·제작 및 기술적 타당성 분석)

  • Lee, Jeong-Ho;Lee, Won-Jae;Yoo, Hyun-Seok;Kim, Young-Suk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.4D
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    • pp.367-376
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    • 2012
  • Crack sealing is a maintenance technique commonly used to prevent water and debris penetration and reduce future degradation in pavement. The conventional crack sealing operations are, however, dangerous, costly, and labor-intensive. Automating crack sealing will improve productivity and quality, and offer safety benefits by getting worker off the road. During the last two decades, several teleoperated and machine-vision assisted systems have been developed to automate the overall process of routing and sealing pavement cracks. However, the developed systems have not been commonly used in the construction sites because of the technical problems. Especially, the performance of end-effector, related to the productivity and quality improvement, is very important factor to improve the practical use of the developed systems. The main objective of this research is to develop an end-effector in automated pavement crack sealing machine and to analyze the technical feasibility of the developed end-effector.

A Study on Measuring Soil-Water Characteristic Curve Using a Suction Control Technique (흡입력 조절 기법을 이용한 함수특성곡선 측정에 관한 연구)

  • Lee, Joonyong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5587-5594
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    • 2012
  • Determination of the soil-water characteristic curve is one of the most important things to solve geotechnical engineering problems. Expecially, convenient and reliable method to measure the soil-water characteristic curve during drying and wetting cycles is required with lower labor input, more independence from operator experience, and shorter testing time than other available methods. Many measurement methods including the flow pump system have been developed to characterize the soil-water characteristic curve for the several decades. This study measured the soil-water characteristic curve during drying and wetting cycles using a suction control technique with the flow pump system. Two test materials were used for determination of the soil-water characteristic curve, and it is concluded that suction control technique is suitable for determination of the soil-water characteristic curve and characterization of the hydraulic hysteresis with varying test conditions. Especially, the suction control technique can reduce error of measurement and save time in measuring the soil-water characteristic curve due to automated system and high degree of precision.

Effect of light illumination and camera moving speed on soil image quality (조명 및 카메라 이동속도가 토양 영상에 미치는 영향)

  • Chung, Sun-Ok;Cho, Ki-Hyun;Jung, Ki-Yuol
    • Korean Journal of Agricultural Science
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    • v.39 no.3
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    • pp.407-412
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    • 2012
  • Soil texture has an important influence on agriculture such as crop selection, movement of nutrient and water, soil electrical conductivity, and crop growth. Conventionally, soil texture has been determined in the laboratory using pipette and hydrometer methods requiring significant amount of time, labor, and cost. Recently, in-situ soil texture classification systems using optical diffuse reflectometry or mechanical resistance have been reported, especially for precision agriculture that needs more data than conventional agriculture. This paper is a part of overall research to develop an in-situ soil texture classification system using image processing. Issues investigated in this study were effects of sensor travel speed and light source and intensity on image quality. When travel speed of image sensor increased from 0 to 10 mm/s, travel distance and number of pixel were increased to 3.30 mm and 9.4, respectively. This travel distances were not negligible even at a speed of 2 mm/s (i.e., 0.66 mm and 1.4), and image degradation was significant. Tests for effects of illumination intensity showed that 7 to 11 Lux seemed a good condition minimizing shade and reflection. When soil water content increased, illumination intensity should be greater to compensate decrease in brightness. Results of the paper would be useful for construction, test, and application of the sensor.

The Examination of Construction Status on Multi-pillar System for Old Age Income Security in Korea (한국 다층노후소득보장체계 구축양태의 경험적 검토)

  • Han, Sinsil;Joo, Soojeong;Shin, Seounghee
    • Korean Journal of Social Welfare
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    • v.67 no.1
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    • pp.215-237
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    • 2015
  • This paper aims to check the multi-pillar pension system in Korea. That is why, We analyzed the insured status of people in terms of multi-pillar pension system including National Pension Service, Private Pension, Retirement Pension over time. The main findings are as follows; firstly, the 'multi-pillar type'(27.7%), the 'public pension type'(12.8%) and the 'insecure type'(59.6%) have been formed. Secondly, any socio-demographic factors like labor market status, gender, age et cetera could not guarantee the pension right for multi-pillar system. As a result, we emphasize that including the 'insecure type' into public pension schemes is a prerequisite for establishing the multi-pillar pension system.

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Tissue Microarrays in Biomedical Research

  • Chung, Joon-Yong;Kim, Nari;Joo, Hyun;Youm, Jae-Boum;Park, Won-Sun;Lee, Sang-Kyoung;Warda, Mohamad;Han, Jin
    • Bioinformatics and Biosystems
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    • v.1 no.1
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    • pp.28-37
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    • 2006
  • Recent studies in molecular biology and proteomics have identified a significant number of novel diagnostic, prognostic, and therapeutic disease markers. However, validation of these markers in clinical specimens with traditional histopathological techniques involves low throughput and is time consuming and labor intensive. Tissue microarrays (TMAs) offer a means of combining tens to hundreds of specimens of tissue onto a single slide for simultaneous analysis. This capability is particularly pertinent in the field of cancer for target verification of data obtained from cDNA micro arrays and protein expression profiling of tissues, as well as in epidemiology-based investigations using histochemical/immunohistochemical staining or in situ hybridization. In combination with automated image analysis, TMA technology can be used in the global cellular network analysis of tissues. In particular, this potential has generated much excitement in cardiovascular disease research. The following review discusses recent advances in the construction and application of TMAs and the opportunity for developing novel, highly sensitive diagnostic tools for the early detection of cardiovascular disease.

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Analysis of the Factors Regarding Work-related Musculoskeletal Disease by Company Size (사업장 규모별 업무상 근골격계질환 요양 실태와 영향 요인)

  • Jung, Sung Won;Kim, Kyung Ha;Suk, Min Hyun;Hwang, Rah Il
    • Journal of Korean Public Health Nursing
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    • v.28 no.3
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    • pp.522-535
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    • 2014
  • Purpose: This study was constructed in order to examine factors that influence work-related musculoskeletal disease (WMSD) approvals and current status according to the company size. Method: This is a descriptive study that utilized Industrial Accident Compensation Claim Data. Workplaces with over 35,811 workers derived from the 2012 claim data, which comprised approximately 91.5%, were selected for this study. Then workplaces were divided into three groups according to the number of workers: less than 5, 5~299, and 300 and over. Results: Since 2008, the number of small sized workplaces has increased. The 2012 data showed that 32.5% of workers at small sized workplace had WMSD. However, workplaces with 5~299 workers showed WMSD approval rate of 60%. Of note most WMSD approved workers were employed by manufacturing and construction companies, regardless of the workplace size. Most of them were engaged in elementary tasks. The days of medical treatment at OPD and IPD were most prevalent among workers at the largest workplaces. Conclusions: It is certain from this study that WMSD has been polarized by the company size. More policy attention should be paid to the WMSD status of workers at small sized workplaces which usually do not have their own health office.