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The Life Course Events and the Career Interruption among Korean Women (여성의 경력단절 기간별 생애사건 효과분석)

  • Min, Hyun-Joo
    • Korea journal of population studies
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    • v.34 no.1
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    • pp.53-72
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    • 2011
  • This study analyzes the effects of life course events and labor market conditions on the duration of career interruption among Korean women. The data were drawn from 'A Survey on the Women's Employment Interruption in Korea' conducted by the Korean Ministry of Gender Equality in 2009(currently the Korean Ministry of Gender Equality and Family). This study categorizes the duration of career interruption into three categories: (1) short term interruption(less than 12months), (2) short-medium term interruptio(12-35 months), (3) intermediate term interruption(36-59 months), (4) long term interruption(longer than 36 months), and then analyzes how demographic factors, labor market condition, and life events shape the timing of re-entry into the labor market among women. According to the findings, the jobs that are conducive to combining market work and mother's role expedite women's return to the labor market. Further, the younger, higher the level of human capital, and higher monthly wages that women earned before leaving the labor market, women are likely to experience short-term interruption(less than 12 months) rather than long-term interruption(longer than 60 months). Women who left from the labor market to care for kids are also likely to return to the labor market. However, women who have preschoolers are likely to experience long-term career interruption. These findings highlight the role of family supportive culture at the workplace in order for women to continue their employment while intensive family formation period. Furthermore, the finding that the discriminatory practices against women, in particular mother workers at the workplace lead women to exit from the market work calls for attention to establish family friendly workplace.

Heat Transfer Characteristics of Water Jet Impinging on Oblique Surface (경사면(傾斜面)에 충돌(衝突) 하는 수분류(水噴流)의 열전달(熱傳達) 특성(特性)에 관(關)한 연구(硏究))

  • Choi, Guk-Gwang;Na, Gi-Dae;Kim, Yeun-Young;Jeon, Sung-Taek;Lee, Jong-Su
    • Solar Energy
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    • v.13 no.1
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    • pp.1-10
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    • 1993
  • The purpose of this research is to investigate the characteristics of heat transfer in the downward axisymmetric free water jet system impinged on a flat oblique plate which has the uniform heat flux. Experimental conditions considered were Reynolds number, distance between nozzle and Bat plate, inclination angle of heater surface and nozzle exit velocity. Local Nusselt number was subjected to the influence of Re number, Pr number, oblique angle of heating surface and local position of flat plate. In the wall region of downward surface, The secondary peak point of heat transfer appeared at the local point of X/D=-8 from the stagnation point. The stagnation heat transfer rate of this experimental study augments 2.4 times than that of laminar theorical solution. The stagnation nusselt number is function of Reynolds number, nozzle-plate spacing Prandtl number and oblique angle of impinging plate.

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Use of Hydrogen Peroxide with Ozone to Simultaneously Reduce MIB and Quench Ozone Residual in Existing Water Treatment Plants Sourcing Water from the Han River (한강을 원수로 하는 오존/과산화수소 고도정수처리공정에서의 MIB제거 및 잔류오존 농도에 관한 연구)

  • McAdams, Stephen R.;Koo, Bon Jin;Jang, Myung Hoon;Lee, Sung Kyoo
    • Journal of Korean Society on Water Environment
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    • v.28 no.5
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    • pp.704-716
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    • 2012
  • This paper provides a detailed account of pilot testing conducted at South Lake Tahoe (California), the Ddukdo (Seoul) water treatment plant (WTP) and the Bokjung (Seongnam) WTP between February, 2010, and February, 2012. The objectives were first, to characterize the reactions of ozone with hydrogen peroxide (Peroxone) for Han River water following sand filtration, second to determine empirical ozone and hydrogen peroxide doses to remove a taste-and-odor surrogate 2-methylisoborneol (MIB) using an advanced oxidation process (AOP) configuration and third, to determine the optimum dosing configuration to reduce residual ozone to a safe level at the exit of the process. The testing was performed in a real-time plant environment at both low- and high seasonal water temperatures. Experimental results including ozone decomposition rates were dependent on temperature and pH, consistent with data reported by other researchers. MIB in post-sand-filtration water was spiked to 40-50 ng/L, and in all cases, it was reduced to below the specified target level (7 ng/liter) and typically non-detect (ND). It was demonstrated that Peroxone could achieve both MIB removal and low effluent ozone residual at ozone+hydrogen peroxide doses less than those for ozone alone. An empirical predictive model, suitable for use by design engineers and operating personnel and for incorporation in plant control systems was developed. Due to a significant reduction in the ozone reaction/decomposition at low winter temperatures, results demonstrate the hydrogen peroxide can be "pre-conditioned" in order to increase initial reaction rates and achieve lower ozone residuals. Results also indicate the method, location and composition of hydrogen peroxide injection is critical to successful implementation of Peroxone without using excessive chemicals or degrading performance.

Development of the 2~8X Zoom Beam Expander for the 1064 nm Laser Source (1064 nm 레이저 관원용 2~8X 줌 빔 확대기 개발)

  • Yi, Meyung-Ha;Lee. Dong-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.2
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    • pp.23-28
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    • 2008
  • Purpose: To develop the 2~8X zoom beam expander for the 1064 nm laser source. Methods: After developing the program by which the initial design values of 3-component zoom tracks can be quickly obtaind, we design and develop the zoom beam expander by applying this program and the commercial program of Sigma 2000. Results: In this study, we could develop the program by which the initial design values of zoom tracks can be quickly obtaind, and by applying this program and the commercial program of Sigma 2000 we could design and develop the zoom beam expander for 1064 nm which is able to zoom from 2${\times}$ to 8${\times}$. The developed zoom beam expander has an efficient diameter of the incidence side of 8 mm, an efficient diameter of the exit side of 32 mm, and a capacity with the finite ray aberration within 0.0001rad. Because the overall length (OAL) is restricted between 125 mm and 135 mm, the change of the whole barrel length which is caused by variations of the zoom driving becomes to be within 10 mm. Conclusions: we could develop the program by which the initial design values of zoom tracks can be quickly obtaind, and by applying this program we could design and develop the zoom beam expander for 1064 nm which is able to zoom from 2${\times}$ to 8${\times}$.

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Situation of Livestock Waste and Strategies for Waste Treatment (축산분뇨의 발생현황과 처리방안)

  • Kim, Chul-Ho
    • Journal of the Korea Organic Resources Recycling Association
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    • v.2 no.1
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    • pp.31-40
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    • 1994
  • In the later part of 1980's, a great emphasis has been placed on the treatment issues of livestock wastes due to the continuous increase in consumption of livestock and meat products. Continued economic development for three decades has enhanced the nationally general level of life for the purpose of exit out of absolute poverty, thus accompanied with people's demand for a quality of environment beyond the traditional economic factors over times. Such an individual or collective demand for environment of life has been primarily focussed and argued on only rural environment in the early development periods. In perspective of clean water supply and security for urban area, however, it is more important to treat livestock wastes in the oriented-sustainable environment than in the conventional ways without working on environment degradation. Livestock wastes composed of the high-concentrated organic matter ought to be controlled and treated in sound ways, if not, which on one hand may result in pollution of underground water, surface water and a nasty smell, and on the other hand also may cause people to file a civil petition. Therefore on the research paper, reviewing occurrence of livestock waste and situation of treatment in details, through scrutinizing the government regulation and financing or subsidizing for it, author intends to find out the initiative of 'resourcefication' of treating of livestock wastes in the environmental soundness and efficiency

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A study on Factors Affecting Willingness to Work of the Self-support Program Participants - A Case Study of Incheon Metropolitan City (단기·장기 자활사업 참가자의 취·창업 의지 영향요인 분석 - 인천광역시 사례 연구)

  • Kyoung, Seung-Ku;Lee, Yong-Gab
    • The Journal of the Korea Contents Association
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    • v.18 no.6
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    • pp.679-690
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    • 2018
  • This study investigated what factors influenced the willingness to work( or start-up) of the self-support program participants. And the hypothesis is that the willingness to work of the self-support program participants would be different according to their duration of program participation. The Survey was conducted participants in 11 local self-support center of Incheon Metropolitan city in the year 2013 and 2016. And it has been analyzed the factors affecting the willingness to work of long-term and short-term participants. The results of this study are as follows. First, the factors affecting all participants's willingness to work ( or start-up) were gender, educational background, experience of employment or start-up, availability of self-support allowance, familiarity with local self-support center's staff, attitude toward work, period of self-support subject participated. Second, long-term participants were affected by disability, educational background, experience of employment or start-up, and availability of self-support allowance. Finally, in the case of short-term participants, it was found that educational background, experience of employment and start-up, availability of self-support allowance, family intimacy and intimacy with local self-support center's staff were influenced.

A Study on the Optimum Design of Horizontal Collectors in Floodplain Filtration (홍수터여과에서 집수관의 최적설계 연구)

  • Pi, Seong-Min;Kim, Seung-Hyun
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.6
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    • pp.430-437
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    • 2012
  • In order to obtain information on the design parameters of the horizontal laterals in floodplain filtration, laboratory-scale sand-box experiments were performed where the head distributions on the laterals and the groundwater profiles were measured according to the change in parameters including lateral diameter, hydraulic conductivity of the sand, water level at the well and raw-water supply rate. Measured data were analyzed using a numerical code in order to identify the discharge intensity distribution along the laterals. It was observed from the result that the lowering of the water level at the well had minimal adverse effect on the performance of the floodplain filtration. Results also elucidated that the low conveyance of the laterals to transmit the filtrate was compensated and supplemented by a natural augmentation in horizontal conveyance through the aquifer when the raw-water supply rate exceeded the adequate recovery rate. With this mechanism, the water quality is expected to improve further since the travel distance through the aquifer is amplified. Based on these findings it can be suggested that the diameter of the lateral used in the floodplain filtration may be smaller than those in riverbank/bed filtration. It was also found that the ratio between the head loss occurring in a lateral and the total head loss in the floodplain filtration was proportional to the exit velocities of the laterals, which may be used to design and/or evaluate the lateral in floodplain filtration.

A Study on Reduction of Nitrogen Oxide (NOx) and Stability of Incineration Facility by the Food Wastewater Incineration (음식물류 폐수 소각처리에 따른 질소산화물 저감 및 소각설비의 안정성 평가에 관한 연구)

  • Hwang, Seung-Min;Chung, Jin-Do;Song, Jang-Heon
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.10
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    • pp.901-908
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    • 2009
  • We examine the processing method of the food wastewater to direct spray at living waste incinerator. The demoscale stoker system is used as a incineration facility. The results show that it brings effect on the reduction of nitrogen oxide ($NO_x$) concentration as well as the ammonia ($NH_3$) amount in SNCR (selective non-catalytic reduction) by the incineration of food wastewater which is containing a plentiful ammoniac nitrogen ($NH_3$-N). Furthermore, the stability of incineration facility and the extension of operation period is actualized as a improvement of clogging phenomenon on outer wall of water pipe as the 870~$950^{\circ}C$ maintain of exit temperature in a second combustor by spray of the food wastewater. The 26 items of air pollution matter of nitrogen oxide ($NO_x$), sulfur oxide ($SO_x$) and dioxin etc. are measured. The results show that it is under the value of allowable exhaust standard.

A Study on the Impacts of Truck Platooning on Freeway Traffic-Flow and the Effect of Dedicated Lane (고속도로 화물차의 군집주행이 교통류에 미치는 영향 및 전용차로 효과 연구)

  • KIM, Joohye;Lee, YoungIhn
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.5
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    • pp.52-69
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    • 2020
  • Considering the need for an infrastructure-level review, this study analyzed the impact of truck platooning on freeway traffic flow and the effect of dedicated lanes based on domestic road and traffic conditions. According to the study, the higher traffic volume and truck ratio, the higher ratio of platoons and the greater size of platoons are formed, which results in greater effect of increasing the average speed of the network. Therefore, the routes with heavy traffic and heavy cargo traffic could be positively considered for truck platooning. However, the analysis showed that the effect of increasing the average speed of the entire network is difficult to expect in the event of a queue due to entry and exit, and that the overall network's throughput could be reduced. Therefore, traffic operation strategies associated with the access road, such as securing capacity of the connection, are needed to maximize the effect of truck platooning. When it comes to the effect of dedicated lane, it could have a positive effect only if one lane was fully operated by automated trucks under the condition of 100% MPR, which allowed positive effects in all aspects, such as higher average speed, throughput, and reduced conflict rates.

A Study on the Choice of Proper Region for Moving Cage Culture Facilities (이동식 가두리 양식장의 이동적지 선정에 관한 연구)

  • 조규대;박성은;고우진
    • Journal of Environmental Science International
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    • v.8 no.1
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    • pp.83-94
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    • 1999
  • A Study on the choice of proper region for moving cage culture facilities were carried out in the South Sea of Korea. Optimum temperatures of habitats for cage culture fishes, Sebastes schlegeli, Paralichthys olivaceus, Seriola quinqueradiata, Lateolabrax japonicus, Pagrus major, Takifugu vermicularis, and Mugil cephalus were 18~26$^{\circ}C$, 10~$25^{\circ}C$, 15~29$^{\circ}C$, 15~29$^{\circ}C$, 15~3$0^{\circ}C$, 15~$25^{\circ}C$, and 19~27$^{\circ}C$, respectively. In winter, wintering regions for continuous growth of fishes were proper around Komundo, Sorido, Soimal, Gadukdo and Chejudo for Paralichthys olivaceus and Lateolabrax japonicus, while Seoguipo and Udo for Seriola quinqueradiata, Pagrus major and Takifugu vermicularis. Sanji was not proper for wintering region because variation of water temperature is large by effect of strong northwestern wind. Wintering regions of Sebastes schlegeli and Mugil cephalus were not in the south of Korea. In summer, proper regions for fishes to avoid from damage by red tide were Komundo and around Chejudo. No red tide has occurred in these regions for 6 years. Mokpo and Yoja Bay were not proper for moving region because the former had strong tides and the latter had only one exit out of the bay which made it impossible to move cages in other route when dangerous red tides burst into.

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