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Characteristics of Recent Foraminifera and Surface Sediments in Gomso- Bay Tidal Flat, West Coast of Korea: Potential for Paleoenvironmental Interpretations (곰소만 조간대의 현생 유공충과 표층 최적물의 특성: 고환경 해석에 적용 가능성)

  • 우한준;장진호
    • 한국해양학회지
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    • v.30 no.3
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    • pp.184-196
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    • 1995
  • The line-SW is located in the mouth of Gomso Bay (20 Km long and 5-8 Km wide),west coast of Korea. This area is composed of sand flat, mud flat, sand shoal and chenier, The difference of physical, geological and geomorphic conditions in subenvironments of the bay may control and produce distingtive foraminiferal populations and assemblages. This study investigates whether five a priori subenvironments (five local zonations) in Gomso-Bay tidal flat can be distinguished from each other on the basis of total (living plus dead) foraminiferal assemblages. Seventy-four species (67 benthic; 7 planktonic) were recorded in total assemblages of surface sediments from 10 stations. Ammonia beccarii tepida, Discorbis candeiana, Elphidium etigoense and Eponides nipponicus were most dominant species in living and total assemblages. The relative abundance (%) of living population was high at upper flat and decreased from upper to lower flat. The low percentages of living populations in middle to lower flat are probably influenced by the decreasing reproduction of foraminifera caused by high energy condition and addition of dead species from offshore. The occurence of planktonic foraminifera in middle to lower flat (5.3∼6.6%) indicates introduction of planktonic foraminifera from offshore by storm and/or tidal current. The relatively high numbers of species in lower middle to lower flat are probably caused by a mixing of faunas from these areas and offshore. The high numbers of total individuals per 50 ml of sediment in upper flat indicate that this area is a relatively stable environment where waves and currents are protected by the chenier. Five biofacies of the total foraminiferal assemblages were established on the basis of dominant species (those representing more than 20% of the total assemblages in any station) in the five a priori subenvironments recognized along the Line-SW transect in Gomso-Bay tidal flat. Five biofacies are potentially useful in paleoenvironmental interpretation in late Quaternary Gomso-Bay tidal deposits.

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A Study on Factors Affecting Youth Employee's Labor Mobility and Employment Status Transition (청년취업자의 노동이동 및 고용형태 전환에 영향을 미치는 요인에 관한 연구)

  • Ban, Jung-Ho;Kim, Kyung-Hee;Kim, Kyung-Huy
    • Korean Journal of Social Welfare
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    • v.57 no.3
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    • pp.73-103
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    • 2005
  • This study takes of youth panel data(2002-2003), there is the purpose to know to youth employed's labor mobility conditions of employment status conversion and examine on factors affecting conversion of employment status. Main analysis result and policy imply, is as following. First, although youth employed's non-standard employment shows some decrease, employment youth hierarchy was construed that youth of our country is consisting very changefully because appear great turnover that is converted by unemployment or Not economically activity population same period. Specially, non-standard employment phenomenon of woman or low in scholarship person appeared notedly, and because phenomenon that is converted by unemployment or Not economically activity population is expose that is deepened, discriminating policy of government dimension is required for employment stabilization of these class. Second, show result that danger to escape to non-standard job risk trap which seeking employment activity of youth class is arranged case or company which is formed by official path is suitable becomes low, must formulate path of employment about youth class and improve qualitative level of employment through suitable job placement education of youth class or function (technology) level. Third, when was construed, but take into account that the although large enterprise have low risk in non-standard job, recently employment of youth class consists very limited, rather small scale business or smaller enterprise's competitive power preferably need to be plan. Finally, danger to non-standard job youth employed's company form is government connection wonder was expose that high, Such result can do that it is difficult by limited research period, but reflect actuality that youth unemployment policy of our country is enforced laying stress on public labor or unregular job employment such as internship system. Therefore, current youth unemployment policy may have to change by employment policy that can secure stable work record by youth class or act as bridge-building that promote conversion by full-time job.

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Estimation of Changes in Potential Forest Area under Climate Change (기후변화하(氣候變化下)에서 잠재삼림면적(潛在森林面積)의 변화(變化) 예측(豫測))

  • Cha, Gyung Soo
    • Journal of Korean Society of Forest Science
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    • v.87 no.3
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    • pp.358-365
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    • 1998
  • To offer the basic information for sustainable production of forest resources and conservation of the global environment, change in potential natural vegetation (PNV) associated with climate change due to doubling atmospheric carbon dioxide ($2{\times}CO_2$) was estimated with the global natural vegetation mapping system based an K${\ddot{o}}$ppen scheme. The system interpolates climate data spherically to each grid cell, determines the vegetation types onto the grid cell, and produces potential vegetation map and area on the globe and continents. The climate data consist of the current, ($1{\times}CO_2$) climate prior to AD 1958 observed at some 2,000 stations and the doubling ($2{\times}CO_2$) climate estimated from Meteorological Research Institute of Japan. The vegetation zone under the $2{\times}CO_2$ climate scenario expanded mainly toward the poles due to the rise in temperature. The changed PNV area on the globe amounts to 1/3 (4.91 billion (G) ha) of the total land area (15.04 Gha). Kappa statistic for judging agreement between the patterns of vegetation distribution under $1{\times}CO_2$ climate and $2{\times}CO_2$ climates shows good agreement (0.63) for the globe as a whole. The most stable areas are desert and ice. The potential forest area (PFA) was estimated at 6.82 Gha of the land area in $2{\times}CO_2$ climate scenario. In terms of continental changes in PFA, North America and Asis are increased under the $2{\times}CO_2$ climate. However, the potential forest arms of the other continents are decreased by the climate. Europe has no change in the PFA. Especially, the expansion of desert area in Oceania would be accelerated by the $2{\times}CO_2$ climate.

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A Study on Comparison of Outdoor Wind Pressure Performance According to Outdoor Exposure and Acceleration Deterioration Methods of Structural Sealants Applied to Curtain Wall (커튼월에 적용된 구조용 실링재의 옥외폭로와 실내복합열화 처리방법에 따른 내풍압성능 비교연구)

  • Jang, Pil Sung;Hong, Soon Gu;Kim, Sung Rae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.279-287
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    • 2018
  • Sealants are an important element of modern architecture and serve as a building protection against weathering by providing barriers against ingress of moisture, air, and other materials. Exposure to a variety of environments often reduces lifespan due to changes in physical, chemical and mechanical characteristics, and UV, humidity, and temperature expansion are important issues that are directly related to durability. In this study, a combined deterioration test chamber was developed to simulate the environment of the open air as an instrument for verifying the durability of structural sealing materials indoors. In order to replicate special weather conditions, such as yellow dust, acid rain, and contamination by microorganisms, it was deemed impossible to replicate the outdoor environment by 100 %, and the results of the results of the results of the external exposure test of the structural sealant and the combined deterioration testing device. As a result of the displacement test of the outdoor exposure test, it was determined that the sealant was breaking apart and that it would be smooth, and the displacement would be up to three times greater than the initial material value of 1 year. The displacement test results of the combined deterioration test device show the tendency to deteriorate, decreasing the elasticity and tensile characteristics. In the case of denatured silicon, the current 400 cycles have been completed to confirm 12 months of degradation of the external exposure. The deformation of the test specimen cannot be verified with the naked eye, so it is considered that the conditions of the specimen are more stable than the silicon sealant. As a result of the outdoor exposure test, if the combined deterioration test device is structured and proposed in the relevant guidance or specification, the anticipated lifespan of 12 months in the actual use environment can be verified indoors and below 3 months later, economically.

Study on the Conservation Management System of China's Natural Reserve (중국 자연보호구의 보전관리체계에 관한 연구)

  • Yao, Zhang;Kim, Dong-Pil;Moon, Ho-Gyeong
    • Korean Journal of Environment and Ecology
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    • v.29 no.3
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    • pp.474-484
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    • 2015
  • This study aims at providing exercisable basic data for the management of protection areas in China by investigating into their legal system such as current laws, regulations, other relevant laws and international treaties and the management system such as history, classification, organization, personnel, funds and main management work.. In People's Republic of China (1954), several laws have been enacted in succession, such as Environment Law (1989), Regulations of Natural Reserves (1994) and Land Management Methods of Natural Reserves (1995). The development process of China's natural reserves is divided into the following five phases. In the initial phase (1956-1965), about 20 natural reserves were established; in the lag phase (1966-1978), a part of the natural reserves was destroyed under the influence of the Great Cultural Revolution; in the development phase (1979-1998), a normative legal system began to appear after the reform and opening up; in the leap phase (1999-2006), the number of natural reserves increased dramatically; in the stable phase ( 2007-present), the protection and restoration of the ecological environment have been implemented, and the supervision and management have been strengthened. China has established natural reserves of national, provincial, municipal and county levels according to the relevant laws. According to the resource categories, natural reserves can be divided into natural ecosystem reserves, wildlife reserves and natural relic reserves. The Ministry of Forestry is in charge of 1,958 natural reserves which account for 74.2 % of the total natural reserves in China. In China, there are 1,384 natural reserves (52.4 %) for which management institutions have been set up. 1,702 natural reserves (64.47 %) are equipped with management staff, showing a higher ratio than the natural reserves which have set up management institutions. China has established natural reserves of national level, provincial level, municipal level and county level according to law. According to the resource categories, natural reserves can be divided into natural ecosystem reserves, wildlife reserves, and natural relic reserves. The Ministry of Forestry is in charge of 1,958 natural reserves which accounts for 74.2 % of the total natural reserves in China. In China, there are 1,384 natural reserves (52.4 %) which have set up management institutions. 1,702 natural reserves (64.47 %) are equipped with management staff with a higher ratio than the natural reserves which have set up management institutions.

Technology for Improving the Uniformity of the Environment in the Oyster Mushroom Cultivation House by using Multi-layered Shelves (느타리버섯 균상재배사의 환경균일성 향상을 위한 기술 개발)

  • Lee, Sunghyoun;Yu, Byeongkee;Kim, Hyuckjoo;Yun, Namkyu;Jung, Jongcheon
    • Journal of Bio-Environment Control
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    • v.24 no.2
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    • pp.128-133
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    • 2015
  • Mushrooms can grow in nature when adequate temperature and humidity are maintained, but such condition can be satisfied for only a short period of time on an annual continuum. Therefore, it can be deemed that a majority of the distributed mushrooms in the current market are produced in an artificially manipulated environment. This study was conducted to resolve the problem of the Oyster mushroom cultivation house's internal temperature and humidity imbalance, where the Oyster mushrooms are cultivated in a multi-layered shelves. The air circulation fans were installed to improve the air uniformity of the Oyster mushroom cultivation house by using multi-layered shelves. During the experiment, the ambient temperature and the ambient relative humidity ranged from $5.2^{\circ}C$ to $20.4^{\circ}C$ and 40% to 100% respectively. Due to the change of the outdoor temperature, the internal temperature of the Oyster mushroom cultivation house also changed, ranging from $13.3^{\circ}C$ to $18.4^{\circ}C$, but the temperature gap between the different internal location of the facility during the conforming recorded time only ranged from $0.2^{\circ}C$ to $1.3^{\circ}C$, being significantly stable. The internal relative humidity, ranging from 82% to 96%, also changed due to the change of the outdoor temperature. Nevertheless, the relative humidity gap between the different internal location during the conforming recorded time only ranged from 2% to 7%. Furthermore, the research staff were able to maintain the concentration of $CO_2$ from 575ppm to 731ppm(below 1,000ppm was the goal) indicating the possibility of an even management of the internal environment by installing the air circulation fan.

A Study on Economic Value of Daegu Arboretum based on Contingent Valuation Methods (가상가치평가법을 이용한 대구수목원의 경제적 가치평가)

  • Kang, Kee-Rae;Lee, Kee-Cheol;Lee, Hyun-Taek;Ryu, Byong-Ro;Kim, Dong-Pil
    • Korean Journal of Environment and Ecology
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    • v.25 no.5
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    • pp.787-798
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    • 2011
  • An arboretum is defined as a collection of facilities that conserve plant species by surveying, collecting, and proliferating and preserving the plants in nature, perform diverse researches on plants and display the plants in exhibition spaces or outdoors as well as provide the public with educational programs and refreshment spaces according to the laws concerned. The public, however, recognizes the exhibition and education functions on plants of arboretum more importantly compared with the roles to survey, collect, and proliferate plants as regulated by the laws. In particular, arboretum plays a role to offer a pivotal educational place in urban area where the public can obtain an hands-on experience and understanding on a wide range of plant species and natural environment. The study aims to estimate the non market environmental values of Daegu Arboretum operated by Daegu Metropolitan City government by using the Contingent Valuation Methods (CVM), which yields the current monetary estimates for the arboretum. The value estimation was undertaken by using the Double-Bound Dichotomous Choice (DBDC) method, and each estimated value was derived from respective functions based on a logit distribution known to include relatively stable estimates according to the shape of the distribution. Considering the statistical fitness test results, the author estimated the amounts of the Willingness To Pay (WTP) such as mean WTP of 12,718 KRW, median WTP of 11,033 KRW, and truncated mean WTP of 11,468 KRW, which represented the annual recreational values per a person visiting Daegu Arboretum respectively. The analysis showed that Daegu Arboretum created the annual environmental values which were estimated to be approximately 16 to 19 billion KRW. The study also has an implication that the valuation method for the environment of Daegu Arboretum may be effectively applied for estimating the values of other types of environmental goods by altering the locations or goods to be analyzed.

COLOR DIFFERENCES BETWEEN RESIN COMPOSITES BEFORE- AND AFTER-POLYMERIZATION, AND SHADE GUIDES (복합레진의 광중합 전·후와 shade guide의 색차 비교)

  • Chon, Yi-Ju;Cho, Sung-Shik;Um, Chung-Moon
    • Restorative Dentistry and Endodontics
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    • v.24 no.2
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    • pp.299-309
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    • 1999
  • The composite resin, due to its esthetic qualities, is considered the material of choice for restoration of anterior teeth. With respect to shade control, the direct-placement resin composites offer some distinct advantages over indirect restorative procedures. Visible-light-cured (VLC) composites allow dentists to match existing tooth shades or to create new shades and to evaluate them immediately at the time of restoration placement. Optimal intraoral color control can be achieved if optical changes occurring during application are minimized. An ideal VLC composite, then, would be one which is optically stable throughout the polymerization process. The shade guides of the resin composites are generally made of plastic, rather than the actual composite material, and do not accurately depict the true shade, translucency, or opacity of the resin composite after polymerization. So the numerous problems associated with these shade guides lead to varied and sometimes unpredictable results. The aim of this study was to assess the color changes of current resin composite restorative materials which occur as a result of the polymerization process and to compare the color differences between the shade guides provided with the products and the actual resin composites before- and after-polymerization. The results obtained from this investigation should provide the clinician with information which may aid in improved color match of esthetic restoration. Five light activated, resin-based materials (${\AE}$litefil, Amelogen Universal, Spectrum TPH VeridonFil-Photo, and Z100) and shade guides were used in this study. Three specimens of each material and shade combination were made. Each material was condensed inside a 1.5mm thick metal mold with 10mm diameter and pressed between glass plates. Each material was measured immediately before polymerization, and polymerized with Curing Light XL 3000 (3M Dental products, USA) visible light-activation unit for 60 seconds at each side. The specimens were then polished sequentially on wet sandpaper. Shade guides were ground with polishing stones and rubber points (Shofu) to a thickness of approximately 1.5mm. Color characteristics were performed with a spectrophotometer (CM-3500d, Minolta Co., LTD). A computer-controlled spectrophotometer was used to determine CIELAB coordinates ($L^*$, $a^*$ and $b^*$) of each specimen and shade guide. The CIELAB measurements made it possible to evaluate the amount of the color difference values (${\Delta}E{^*}ab$) of resin composites before the polymerization process and shade guides using the post-polishing color of the composite as a control, CIE standard D65 was used as the light source. The results were as follows. 1. Each of the resin composites evaluated showed significant color changes during light-curing process. All the resin composites evaluated except all the tested shades of 2100 showed unacceptable level of color changes (${\Delta}E{^*}ab$ greater than 3.3) between pre-polymerization and post-polishing state. 2. Color differences between most of the resin composites tested and their corresponding shade guides were acceptable but those between C2 shade of ${\AE}$litefil and IE shade of Amelogen Universal and their respective shade guides exceeded what is acceptable. 3. Comparison of the mean ${\Delta}E{^*}ab$ values of materials revealed that Z100 showed the least overall color change between pre-polymerization and post-polishing state followed by ${\AE}$litefil, VeridonFil-Photo, Spectrum TPH, and Amelogen Universal in the order of increasing change and Amelogen Universal. Spectrum TPH, 2100, VeridonFil-Photo and ${\AE}$litefil for the color differences between actual resin and shade guide. 4. In the clinical environment, the shade guide is the better choice than the shade of the actual resin before polymerization when matching colors. But, it is recommended that custom shade guides be made from resin material itself for better color matching.

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Changes in Pectic Enzyme Activity during Maturation of Tomato Fruit and Purification, Some Properties of Polygalacturonase Isozymes (Tomato 성숙중(成熟中) Pectin 효소(酵素)의 활성변화(活性變化)와 Polygalacturonase의 분리(分離) 및 그 성질(性質))

  • Suh, Cha Hwan;Sohn, Tae Hwa;Choi, Jong Uck;Choi, Sang Won
    • Current Research on Agriculture and Life Sciences
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    • v.4
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    • pp.42-49
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    • 1986
  • The changes in pectinesterase (PE) and polygalacturonase (PG) activities were investigated during maturation and ripening of tomato fruits. PG was isolated from ripe tomatoes and purified by using DEAE-sephadex A-50 column chromatography. Its property was examined by general methods. PE activity was increased during maturation and then peaked at the on set of color change. PG activity was not detectable in mature green tomato fruits but increased during softening. Slab electrophoresis of the crude enzyme isolated from ripe tomatoes shoed 6 bands. Two polygalacturonase (PGI, PGII) were separated from crude enzyme of ripe tomatoes by chromatography on DEAE-sephadex A-50. PGI and PGII were purified by 61 fold and 98 fold by the present procedure, respectively. The Rm values of partially purified PGI and PGII were estimated to be 0.25 and 0.31, respectively. The optimum temp, and pH of PGI activity were $37^{\circ}C$ and pH 4.5, while those of PGII activity were $40^{\circ}C$ and pH 4.7, respectively. Isozyme PGI activity was the most stable at pH 4.3 and retained 50% of its activity when exposed at $78^{\circ}C$ for 5 min.

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A Study on the Effect of SMEs' Organizational Culture and Self-Efficacy on Job Crafting and Job Satisfaction (소기업의 조직문화와 자기효능감이 잡 크래프팅과 직무만족도에 미치는 영향에 관한 연구)

  • Bae, Keun Soo;Heo, Ghul Moo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.5
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    • pp.109-124
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    • 2021
  • This study tried to verify the causal relationship that SMEs' organizational culture and self-efficacy would affect job crafting and job satisfaction. Unlike previous domestic studies that have been studied for organizational culture at the organizational level and self-efficacy at the individual level, this study tried to verify the interaction between job crafting and job satisfaction using different mechanisms as antecedent factors. In order to verify the research model of this study, questionnaires of 144 small and medium-sized enterprises (SMEs) workers located in Seoul and metropolitan areas were analyzed. Factor analysis and correlation analysis were performed to verify the reliability and validity of the research model on the relationship between variables, and empirical analysis was performed using regression analysis and mediation effect analysis to verify the hypothesis. The results of the study were first, that organizational culture and self-efficacy had a positive (+) effect on job crafting. On the other hand, relationship-oriented culture and hierarchical-oriented culture, which are sub-factors of organizational culture, were found to be insignificant. Second, organizational culture and self-efficacy were found to have a positive (+) effect on job satisfaction. On the other hand, it was found that market-oriented culture and hierarchical-oriented culture, which are sub-factors of organizational culture, were not significant. Third, job crafting was found to have a positive (+) effect on job satisfaction. On the other hand, it was found that the sub-factors of job crafting, disruptive job demands and social job resources, were not significant. This means that organizational culture partially affects job crafting and job satisfaction of SMEs, and job crafting also partially affects job satisfaction. The implications of this study are first, suggesting the meaning of SME organizational culture for stable and efficient human resource management for SMEs suffering from low productivity and high turnover rate. Second, it was meaningful to understand the possibility of introducing job crafting as an effective job management plan for SMEs. Third, in the current situation where there are few cases of practical introduction of job crafting, research on understanding job crafting for SMEs and improving job satisfaction is thought to be helpful in improving the productivity of SMEs.