• Title/Summary/Keyword: Dead Zone

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Distribution and Stand Dynamics of Subalpine Conifer Species (Abies nephrolepis, A. koreana, and Picea jezoensis) in Baekdudaegan Protected Area (백두대간 보호지역 내 아고산 침엽수종(분비나무, 구상나무, 가문비나무)의 분포 현황과 임분 변화 특성)

  • Park, Go Eun;Kim, Eun-Sook;Jung, Sung-Cheol;Yun, Chung-weon;Kim, Jun-soo;Kim, Ji-dong;Kim, Jaebeom;Lim, Jong-Hwan
    • Journal of Korean Society of Forest Science
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    • v.111 no.1
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    • pp.61-71
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    • 2022
  • Data from an investigation of vulnerable conifer species in the subalpine zone in Korea obtained by the Korea Forest Service in 2017-2018 and monitoring research conducted by the National Institute of Forest Science since 2014 were used to analyze the status of distribution and growing condition of three major conifer species (Abies nephrolepis, Abies koreana, and Picea jezoensis) in the subalpine zone in the Baekdudaegan protected area. The distribution area of the studied species in the Baekdudaegan protected area was ca. 74% (8,035 ha) of the total distribution area in Korea, indicating that Baekdudaegan is a core area for conservation and restoration of subalpine conifer species. From decline index [A. nephrolepis in Mt. Taebaeksan and Mt. Deogyusan increased by 77.3% and 29.6%, respectively; A. koreana in Mt. Jirisan (Chunwangbong Peak) increased by 45.2% in four years; and P. jezoensis in Mt. Jirisan (Chunwangbong Peak) increased by 47.8% in two years] and seedling frequency (lower frequency of newly recruited seedlings than dead seedlings) results, the studied species are expected to face difficulties in sustainability. In contrast, at Mt. Seseoksan and Chunwangbong Peak in Mt. Jirisan, the health of trees and seedling frequency showed a partial tendency to recover and increase. In addition, we identified the relationship between the decline index and seedling frequency. These results will support the implementation of conservation strategies for vulnerable conifer species in the subalpine zone.

Numerical Investigation of Exhaust Gas Recirculation Effect under Boost Pressure Condition on Homogeneous Charge Compression Autoignition (HCCI엔진의 과급조건에서 EGR영향에 대한 수치해석적 연구)

  • Oh, Chung Hwan;Jamsran, Narankhuu;Lim, Ock Tack
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.6
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    • pp.451-464
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    • 2014
  • This study used numerical methods to investigates investigate the exhaust gas recirculation (EGR) effect under the condition of boost pressure condition on a homogeneous charge compression ignition (HCCI) combustion engine using numerical methods. The detailed chemical-kinetic mechanisms and thermodynamic parameters for n-heptane, iso-octane, and PRF50 from the Lawrence Livermore National Laboratory (LLNL) are were used for this study. The combustion phase affects the efficiency and power. To exclude these effects, this study decided to maintain a 50 burn point (CA50) at 5 CA after top dead center aTDC. The results showed that the EGR increased, but the low temperature heat release (LTHR), negative temperature coefficient (NTC), and high temperature heat release (HTHR) were weakened due by theto effect of the O2 reduction. The combined EGR and boost pressure enhanced the autoignition reactivity, Hhence, the LTHR, NTC, and HTHR were enhanced, and the heat-release rate was increased. also In addition, EGR decraeased the indicated mean effective pressure (IMEP), but the combined EGR and boost pressure increased the IMEP. As a results, combining the ed EGR and boost pressure was effective to at increase increasing the IMEP and maintaining the a low PRR.

Preliminary Nitrogen Removal Rates in Close-to-Nature Constructed Stream Water Treatment Wetland (하천수정화 근자연형 인공습지의 초기 질소제거)

  • Yang, Hong-Mo
    • Korean Journal of Environmental Agriculture
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    • v.21 no.4
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    • pp.269-273
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    • 2002
  • A 0.19 hectare stream water purification demonstration wetland was constructed and planted with cattails from April 2001 to May 2001. Some portions of its bottom surfaces adjacent to levees have a variety of slope of 1:4 $\sim$ 1:15 and two small open water areas were installed in the wetland. These make its shape closer to a natural wetlant Nitrogen removal was a major objective of the wetlant Waters of Sinyang Stream flowing into Kohung Esturiane Lake located southern coastal region of Korean Peninsula were pumped and funneled into it. Volumes and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Average inflow and outflow were 120 $m^3/d$ and 112 $m^3/d$, respectively. Hydraulic retention time was about 3.1 days. Average nitrate and total nitrogen removal rate for the early stage of the wetlands were 85.8 $mg/m^2/day$, 171.4 $mg/m^2/day$ respectively. Full establishment of cattails within a few years can develope litter-soil substrates and supply available carbon sources beneficial to the denitrification of nitrate. These can lead to increases of the nitrate retention rate. Short circuiting and dead zone areas which might be occurred due to the close-to-nature layout of the wetland were not observed during the monitoring period.

Security Problem of National Major Facility's Parking Lot and its Improvement Method -Focused on Doonchi(Waterside) Parking Lot of National (국가중요시설의 주차장 보안의 문제점과 개선방안: 국회둔치주차장을 중심으로)

  • Lee, Sang-Hun;Lee, Sang-Yeol
    • Korean Security Journal
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    • no.50
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    • pp.61-87
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    • 2017
  • National Assembly is a constitutional institution that is required to first consult the will of the people and it should do its effort continuously so that security of citizens using parking lot would be enhanced at the same time while improving parking service in order to increase customer satisfaction of the people. Under this recognition, in this study, Doonchi parking lot of National Assembly under consigned management was first reviewed in a perspective of criminal prevention through environmental design(CPTED) and particularly, fence installation and reinforcement work for securing 'territoriality' and operation of all round shooting camera and installation of No-trespassing warning board at entrance were suggested. Second, it was recommended to change independent control system in which CCTV security system of National Assembly Doonchi parking lot is operated separately from National Assembly safety situation room and integrate it with National Assembly safety situation room(revised to double safety system) and performance of CCTV camera was made to be increased to over 2m. In addition, video recording mode was converted to NVR mode for application to IP camera in the future and in order to avoid dead zone of security monitoring area and based on site inspection result, addition 3 places of newly installing CCTV were indicated. Third, it was recommended to introduce parking fare billing and management system through unmanned equipment in parking lot management and operation.(specialized management of professional parking service provider was reviewed). By doing so, risk of cash handling by charging personnel was removed by reducing current 7 working personnel to 3 and particularly, by converting parking lot management mode being operated temporarily from 9 A.M. to 9 P.M. at present to 24 hours operation mode and providing more specialized parking service, citizens visiting National Assembly were provided with convenience and image of National Assembly was also enhanced. This study was carried out in parallel with various literature and case studies, including data from the Office of the Defense Protection in the National Assembly.

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French 'Minima Sociaux's Scheme, Benefit Determination Rule and its Appreciation : A Study on Social Assistance in Europe (프랑스 사회적 미니멈(Minima sociaux)의 구조 및 급여 체계 : 유럽 공공 부조 제도의 한 연구)

  • Shim, Chang-Hack
    • Korean Journal of Social Welfare
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    • v.59 no.3
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    • pp.75-97
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    • 2007
  • The purpose of this article is to explore French 'minima sociaux', focusing its scheme, benefit determination rule and its level appreciation. First, on the its structure domain, French 'minima sociaux' presents the plural system in which there is eight categorical benefits and one general benefit. Il is the representation of the intention to guarantee minimum income for the dead zone people out of the social insurance application and also a historical product in different period, by different logic of benefits implementation. Second, comparing nine benefits based on the benefit determination rule, level of benefits for the poor without work ability is higher than one for the poor with work ability. Il represents one polarized perception toward for the poor according to have or not its work ability. Third, comparing level of 'minima sociaux' with relative poverty line, the level of the most 'minima sociaux' is placed under the poverty line. Nevertheless, it must not forget that 'minima sociaux' plays its role as the fundamental alternative for poverty alleviation, but not the only alternative. Fourth and finally, comparing with minimum income guarantee(SMIC in french), level of RMI benefit is estimated merely on the 50% of SMIC. We can consider that it is the result of the interaction of the complex factors, as the limited role of the state toward the minimum income guarantee for the RMI beneficiary and the intervention the logic of status instead of the logic of need, etc..

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A Gender-Sensitive Analysis on the scale and causes of the blind spots in the employment insurance system (고용보험제도의 실질적 사각지대 규모와 원인에 대한 성별 분석)

  • Kim, Hyeyoun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.3
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    • pp.108-117
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    • 2020
  • The purpose of this study is to analyze the blind spots of Korea's employment insurance system from a gender perspective. The data used for this study was derived from 12th (2009) and 20th (2017) years of the Korean Labor and Income Panel Studies. Logistic regression analysis was performed to analyze the causes of the blind spot. As a result, the gender gap decreased by 5% in 2017 compared to that in 2009. In the coverage of employment insurance by gender, women are more likely to join when controlling for other demographic factors. If the conditions in the labor market are the same, then women's insurance coverage is likely to be higher than that of men. The policy suggestions are as follows. The current employment insurance system has a greater impact on the labor market characteristics than the difference in the participation rate according to gender itself. The results of this study show that bridging the gender gap in the labor market is an important way of bridging the gender gap in employment insurance coverage. In the short term, the social insurance subsidy program may be effective, but policy efforts are fundamentally needed to improve the employment environment of women and low-wage workers.

Spatial Inequality of the Distribution of Daycare Centers and Consideration of Countermeasures : The Case of Daycare Centers in Jeollanam-Do (어린이집 분포의 공간적 불균형과 그 대책에 대한 고찰 - 전라남도 어린이집을 중심으로 -)

  • Seol, Seonmi;Lee, Taesoo;Shim, Miseung;Jang, Guhn-Choon
    • Journal of the Korean association of regional geographers
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    • v.21 no.4
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    • pp.716-727
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    • 2015
  • The location and distribution of daycare centers do not reflect local daycare demand enough although government has increased facilities and financial supports to solve the low birthrate as a social problem. This study tried to examine spatial inequality of daycare center distribution by comparing the number of daycare facilities between city and rural communities in Jeollanam-Do. Analyzing the differences between city (5 Cities) and rural area (17 Guns) in Jeollanam-Do, it has been found that there were large differences in the number of available facilities per 1,000 children between Cities (10.9 facilities) and Guns as rural area (6.2 facilities). The average number of facilities in each City and Gun also showed a large discrepancy as a City has 147.8 facilities and a Gun has 15.4 facilities, respectively. There were total 78 Dong or Myeon with no facility at all as a dead zone of daycare, and 8 of them were Myeons in cities with 560 children, which accounted for 0.7% of total population of children in cities. On the other hand, 70 Myeons in Guns with 5,269 children have no facilities at all, which accounted for 11% of total population of children in Guns. Public facilities that parents prefer were more in cities (87) than Guns (28). Therefore, it is necessary to consider various childcare policies with minimizing discrepancies between city and rural area and investigating more accurate local demands and characteristics.

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Bacterial Blight of Sesame Caused by Xanthomonas campestris pv. sesami (Xanthomonas campestris pv. sesami에 의한 참깨의 세균성잎마름병)

  • Lee Seung-Don;Lee Jung-Hee;Kim Yong-Ki;Heu Sung-Gi;Ra Dong-Soo
    • Research in Plant Disease
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    • v.11 no.2
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    • pp.146-151
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    • 2005
  • A new bacterial disease of sesame(Sesamum indicum) was observed on field-grown plants in Suwon, Hongchun and Yeonchun in 2000. Leaf symptoms initially appeared as water-soaked spots that gradually enlarged, became necrotic and were often bordered by a small zone of lemon yellow tissue. In the case of severe infection, dead leaves were defoliated. Isolations made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow-pigmented bacterium typical of a xanthomonad. Two bacterial strains were purified and used for farther tests. Pathogenicity of strains was confirmed on 3-week-old sesame plants sprayed with bacterial suspensions containing $10^{8}cfu/ml$ of phosphate buffered saline. The Biolog and fatty acid analyses of the two strains(SL3451 and SL3476) 1mm sesame leaf blight showed that they could be identified as ft campestris pv. sesami because of their high similarity to the tester strain(X. campestris pv. sesami LMG865) with a match probability of $100\%$. The bacterium grew well between 18 and 36$^{\circ}C$, but optimum temperature was $27^{\circ}C$ on LB broth. This is the first report of bacterial blight of sesame in Korea. Symptoms of bacterial blight of sesame are difficult to differentiated with those of bacterial leaf spot caused by Pseudomonas syringae pv. sesami.

Effect of Salinity on the Survival and Growth of Larvae of the Boreal Digging Frog (Kaloula borealis) (맹꽁이 유생의 생장과 생존에서의 염분영향)

  • Ko, Sang-Beom;Ko, Young-Min;Lee, Jeong-Hyun
    • Korean Journal of Environment and Ecology
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    • v.29 no.4
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    • pp.533-538
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    • 2015
  • This study was conducted to examine the effect of salinity on the early embryonic development stage of boreal digging frogs (Kaloula borealis). An experiment was carried out with the eggs of K. borealis mating couples laid along the coastal zone of Jeju Island in June 2013. The salinity was set to 0, 1, 3, 5, and 7 ‰, respectively. The survival and growth of the larvae at various stages from the egg phase to the closing of their external gills phase were observed. In another experiment, tadpoles in internal gill stage were placed in solutions with salinity of 0, 1, 3, 5, and 7 ‰, respectively, and their survival rate and growth rate were observed, and then the results of the two experiments above were compared. The results showed that in egg and external gill stage, there was no significant difference in survival rate in 3 ‰ solution, though there was low survival rate in 5 ‰ solution. Further, all the eggs were dead in 7 ‰ solution, so it appeared that solutions with salinity of 5 ‰ or higher affect the survival of K. borealis in the early embryonic development. Larvae in the internal gill stage showed no significant difference in survival rate from the control group up to a salinity of 5 ‰, but when placed in a solution of over 7 ‰ salinity, the survival rate decreased. The growth rate also slowed down with the higher salinity. It appeared that in both the external gill stage and the internal gill stage in 5 ‰ solution, the growth rate decreased significantly compared to the control group. From this study it is concluded that higher salinity values have a significant impact on the survival and growth of the K. borealis larvae and this finding can be used to conserve K. borealis species that are decreasing in number due to the side effects of development in coastal areas.

Fuzzy Control for the Obstacle Avoidance of Remote Control Mobile Robot (원격제어 이동로봇의 장애물 회피를 위한 퍼지 제어)

  • Yeo, Hee-Joo;Sung, Mun-Hyun
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.1
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    • pp.47-54
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    • 2011
  • The remote control mobile robot is the robot accomplishing a task according to the orders giving by a user through departed communication system using a joystick. Basically, to supply a lot of information, as this type of robot uses visual information, the user can check the transmitted information by eyes and give orders to the robot. But the weak point of this type of robot is that it has a possibility to come into a collision with an obstacle not be seen to the user because of the communication delay occurring in a communication system and dead zone happening in visual information. To solve the problem, in this paper, we try to suggest a system applying a fuzzy control system to the robot to avoid collision with an obstacle by an immediate order of the user. The fuzzy control system has better performance than any other existing control methods in the change of noise and parameter. And it is more efficient than any other since it solves easy the complexity of the system analysis occurring because of the nonlinear feature of the mobile robot system. In this paper, we made experiments how the mobile robot controlled by the fuzzy control system avoids an obstacle, tracks the path and avoids the obstacle in the path, to prove the performance and to check the evaluation and the application possibility of the fuzzy control system.