• Title/Summary/Keyword: Effective field size

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Sampling and Cryogenic Pulverization and Storage of Environmental Samples and Improvement of Operating Procedures in National Environmental Specimen Bank (국가환경시료은행 시료 채취, 분쇄, 저장과 개선방안 고찰)

  • Lee, Jangho;Lee, Jongchun;Kim, Myungjin;Han, Areum;Lee, Eugene;Bade, Rabindra;Kim, Minsung
    • Journal of Environmental Impact Assessment
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    • v.21 no.6
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    • pp.823-839
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    • 2012
  • Environmental Specimen Banks (ESBs) are playing pivotal role in monitoring the effect of environmental pollution on the ecosystem based on the retrospective analysis of the representative samples collected regularly and stored in cryogenic condition. In Korea, National Environmental Specimen Bank (NESB) was established in 2009 and the standard operating procedures (SOPs) for sampling, and cryogenic milling and storage had been prepared during 2007-2010. Since then, the tentative SOPs for the seven kinds of specimens (shoots of Red Pine (Pinus densiflora) and Korean Pine (Pinus koraiensis), leaves of Mongolian Oak (Quercus mongolica) and Zelkova Tree (Zelkova serrata), eggs of Feral Pigeon (Columba livia var. domestica), muscles and organs of Common Carp (Cyprinus carpio), and Freshwater Bivalve (Unio (Nodularia) douglasiae)) have been put to test in the field and laboratory as well against the practicality and feasibility. The SOPs were improved by reflecting the findings from the research and the following discussion regarding the selection of specimen (Feral Pigeon suffering from a control management), sample size (a problem of decreasing number of sampling trees related to increasing sampling time) and period (a problem related to a bud growth), and sampling methods etc.. In addition, barcoding system for the management of the specimen information, and monitoring system of the cryogenic storage to regulate the optimum temperature and the liquid nitrogen level were also developed for the efficient and effective control of the samples. Lastly, the safety guide and emergency protocol were augmented to guarantee a safe work environment with the cryogenic facility. These improvements of the SOPs are expected to contribute to more stable operation of the NESB.

Study on Channel-bed Fluctuation Using Aerial Photographs(II) -Analysis of spatial-temporal distribution on the deposits- (항공사진(航空寫眞)을 이용(利用)한 하상변동(河床變動)에 관한 연구(硏究)(II) -하상퇴적지(河床堆積地)의 시(時)·공간적(空間的) 분포(分布) 해석(해석)-)

  • Chun, Kun Woo;Kim, Kyoung Nam;Cha, Du Song
    • Journal of Korean Society of Forest Science
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    • v.84 no.3
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    • pp.369-376
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    • 1995
  • Black and White aerial photogrphs are much useful to obtain the information on the channel-bed fluctuation in the following aspects. 1. In the decision of river width, the linear regression formula between the value of aerial photograph interpretation and that of field surveying is Y=1.0+0.94X(the decision coefficient is $r^2=0.98$). Therefore, aerial photographs are proved effective for the measurement of river width. 2. Aerial photograph interpretation makes it possible to classify the plane channel and the deposits in river, and suggests the situation of the plane distribution of deposits, the size of channel and the course of channel formation. 3. The periodical channel situation can be figured out through the interpretation of aerial photographs pictured in different times. Also, the comparing and analyzing each interpretated information can be able to guess the course of the variation of channel influencing powerfully channel - bed fluctuation. 4. The microtopographic map of river can be made through the decision of river with, the interpretation of the plane shape of channel - bed and the analysis of variation of channel. On the basis of this map, the plane analysis of deposit is possible.

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Patterns of Snake Roadkills on the Roads in the National Parks of South Korea (국립공원 내 도로에서 뱀류 로드킬 현황)

  • Kim, Seok-Bum;Lee, Jung-Hyun;Park, Daesik
    • Korean Journal of Ecology and Environment
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    • v.51 no.3
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    • pp.234-244
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    • 2018
  • The roadkill that animals die after bumping by vehicles on the roads is acting as a factor to decrease the size of various animal populations. It has also been known to be the biggest artificial causations of Vertebrata deaths not only in urban areas but also protected areas such as national parks. Nevertheless, in the national park areas which are major protected national areas for conservation of national biodiversity and ecological diversity, snake roadkills occur frequently. Up to date, related studies are rare. Therefore, in this study, we described snake roadkill patterns on the roads in six national parks between 2006 and 2015. We identified total 736 snake roadkills compromising 10 different species. Five species, Rhabdophis lateralis, Elaphe dione, Gloydius ussuriensis, Lycodon rufozonatus, Gloydius brevicaudus occupied more than 91.7% of total roadkill cases. Active forager snakes were killed by roadkills more than ambush foragers, and the snake roadkill frequency was the highest in September, a migration period and in August when the young individuals dispersed at between 100 and 799 m altitude areas. Roads where roadkills were frequent lie between forest and hydrosphere or between forest and crop field road sides. Our results could be used to identify the trend of snake roadkills on the roads in national parks, and to establish effective roadkill mitigation measures and policies.

Revitalizing the Young Venture Entrepreneurship through Grounded Theory (근거이론에 기반한 청년 벤처 창업 활성화 방안 연구)

  • Kim, Na Rang;Hong, Soon Goo;Lee, Hyun Mi
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.3
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    • pp.33-45
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    • 2014
  • The Government of South Korea is actively promoting entrepreneurship policies to help solve an age old problem of unemployment; however, the unemployment rate of youth entrepreneurship remains at a low. Primarily due to the government fragmented policies that are unable to solve the daily difficulties young entrepreneurs undergo. Therefore, this study aims at deriving a modern solution to an age old problem that exists through the use of co-creation by first interviewing young entrepreneurs to help derive a paradigm model. The model was developed through a grounded theory approach to help strengthen the young venture entrepreneurs. The results revealed that majority of the young entrepreneurship revitalization policies had exclusive participation structure, allowing only a selected few: complex policies of various government departments, short-term funding, one-size-fits-all training and support, lack of follow-up support policies after start-up, excessive administrative requirements, and performance-oriented fragmented support. Concluding that the policies were unrealistic and ineffective for the entrepreneurs. Accordingly, the result suggests that Co-creation entrepreneurship revitalization policy, based on the experiences of entrepreneurs, will need to be established to formulate an effective policy that provides practical assistance to the entrepreneurs in the field.

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Facile Synthesis of In2S3 Modified Ag3PO4 Nanocomposites with Improved Photoelectrochemical Properties and Stabilities

  • Zeng, Yi-Kai;Bo, Shenyu;Wang, Jun-hui;Cui, Bin;Gu, Hao;Zhu, Lei;Oh, Won-Chun
    • Korean Journal of Materials Research
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    • v.30 no.11
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    • pp.601-608
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    • 2020
  • In this work, Ag3PO4/In2S3 nanocomposites with low loading of In2S3 (5-15 wt %) are fabricated by two step chemical precipitation approach. The microstructure, composition and improved photoelectrochemical properties of the as-prepared composites are studied by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photocurrent density, EIS and amperometric i-t curve analysis. It is found that most of In2S3 nanoparticles are deposited on the surfaces of Ag3PO4. The as-prepared Ag3PO4/In2S3 composite (10 wt%) is selected and investigated by SEM and TEM, which exhibits special morphology consisting of lager size substrate (Ag3PO4), particles and some nanosheets (In2S3). The introduction of In2S3 is effective at improving the charge separation and transfer efficiency of Ag3PO4/In2S3, resulting in an enhancement of photoelectric behavior. The origin of the enhanced photoelectrochemical activity of the In2S3-modified Ag3PO4 may be due to the improved charge separation, photocurrent stability and oriented electrons transport pathways in environment and energy applications.

Microsurgical Training using Preserved Saphenous Vein (혈관문합 연습을 위한 보존된 복재정맥의 활용)

  • Song, Jennifer K.;Hwang, So-Min;Lim, Kwang-Ryeol;Jung, Yong-Hui
    • Archives of Plastic Surgery
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    • v.37 no.4
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    • pp.391-395
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    • 2010
  • Purpose: Given that the critical nature of the microvascular anastomosis to what is often a long and difficult reconstructive operation, trainees need to have a high level of microsurgical competence before being allowed to perform microsurgery on patients. Some artificial substitutes and dead or live animal models have been used to improve manual dexterity under the operating microscope. Yet, most surgeons are not equipped with such models, so search for easy available and appropriate microsurgical practice model have been an issue. Umbilical artery, placental vessels and gastroepiploic arteries have been previously suggested as a microsurgical training model, which involves other surgical departments. The purpose of this article is to introduce that saphenous vein specimen obtained from varicose vein surgery is useful and has many advantages as training model for the practice of microvascular anastomosis. Methods: The conventional technique using perforation/inversion method with a metallic stripper is widely performed for varicose vein patients. The stripper is inserted through disconnected safeno-femoral junction and retrieved at the knee or the medial side of ankle. The length of saphenous vein specimens removed is about that of one's leg and inversed from inside out. Obtained saphenous vein specimens are re-inversed and cleansed with normal saline, to be readily available for microsurgical practice. Preserved in a squeezed wet saline gauze and refrigerated, frozen or glycerated specimens were investigated into their comparative quality for microsurgical practice. Results: Varicose vein surgery remains one of the common operations performed in the field of plastic surgery. Convenient informed consent regarding the vessel donation can be easily signed. The diameter of the obtained saphenous vein is as variable as 1.5 to 6 mm, which is already stripped, and is in sufficient length corresponding to that of patient's leg. Vessels specimens were available for microsurgical practice within 1 week period when preserved with squeezed wet saline gauze, and the preservation period could be extended monthly by freezing it. Conclusion: Saphenous vein obtained from varicose vein patients provide with variable size of vessel lumen with sufficient length. The practice can be cost effective and does not require microsurgical laboratory. Additionally there is no need of involving other surgical departments in acquiring vessel specimens. Furthermore, simple preservation method of refrigerating for a week or freezing with squeezed wet saline gauze for a month period, allow the saphenous vein obtained after varicose vein surgery as an excellent model for the microsurgical practice.

Out-of-School Educatin for the Gifted and Talented around the World

  • Freeman, Joan
    • Journal of Gifted/Talented Education
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    • v.14 no.3
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    • pp.41-52
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    • 2004
  • No educational provision for the gifted and talented works in a cultural vacuum, and this is as true for out-of-school activities as for what happens in school itself. There is evidence that excellence in children's achievements can come from widely differing special provision or from no special provision at all. Cultural influences affect attitudes as to who might be gifted and talented and what might be done for them. Whatever the size and influence of special centres anywhere, there is always overlap between in-school and out-of-school activities. For all styles of provision, cooperation between the two is a vital aspect of success. The major cultural dichotomy in this field is between the perception, usually found in the Far East that 'most children have gifted potential' and the largely Western view that 'few children have gifted potential'. It is safe to say that children who are selected for aptitude and ability, and who are keen to learn, will get more from special enrichment than those who of equal potential who have not had that experience. But this does not necessarily show the provision as the best possible method for enhancing gifts and talents. In fact, I do not know of a single scientific investigation, either cross-culturally or within one country, which compares any aspect of an out-of-school programme with another. As a result it is hard to say what type of provision would be most appropriate and effective in any given situation. Outcomes are also dependent on the enthusiasm, organisation and money put into any scheme - as well as the way youngsters are chosen for it. Some of the largest and most influential out-of-school American institutions were founded on the psychological understanding of human abilities that was current in the 1920s. These early influences of seeking an IQ cut-off point (or equivalent) to identify the gifted still affect their practice. in addition, the big American Talent Searches so often select youngsters for summer-schools not only by their high-level achievements, but also by their parent's ability to pay the sometimes high fees. Opinions about the identification of the brightest children and consequential educational practice underlie all provision for their education, whether in or outside school hours. Because of cross-cultural differences, it would not seem wise to copy any action directly from one culture to another without recognising these influences and possibly modifying the model. The growing trend around the world is to offer high-level opportunities to as many youngsters as possible, so that no keen learner is turned away without even a change of sampling them.

Mobile Presentation using Transcoding Method of Region of Interest (관심 영역의 트랜스코딩 기법을 이용한 모바일 프리젠테이션)

  • Seo, Jung-Hee;Park, Hung-Bog
    • The KIPS Transactions:PartC
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    • v.17C no.2
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    • pp.197-204
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    • 2010
  • An effective integration of web-based learning environment and mobile device technology is considered as a new challenge to the developers. The screen size, however, of the mobile device is too small, and its performance is too inferior. Due to the foregoing limit of mobile technology, displaying bulk data on the mobile screen, such as a cyber lecture accompanied with real-time image transmission on the web, raises a lot of problems. Users have difficulty in recognizing learning contents exactly by means of a mobile device, and continuous transmission of video stream with bulky information to the mobile device arouses a lot of load for the mobile system. Thus, an application which is developed to be applied in PC is improper to be used for the mobile device as it is, a player which is fitting for the mobile device should be developed. Accordingly, this paper suggests mobile presentation using transcoding techniques of the field concerned. To display continuous video frames of learning image, such as a cyber lecture or remote lecture, by means of a mobile device, the performance difference between high-resolution digital image and mobile device should be surmounted. As the transcoding techniques to settle the performance difference causes damage of image quality, high-quality image may be guaranteed by application of trial and error between transcoding and selected learning resources.

Dredging Material Application Lightweight Foamed Soil Full Scale Test Bed Verification (준설토 활용 경량기포혼합토 실규모 현장 실증 연구)

  • Kim, Dong-Chule;Yea, Gue-Guwen;Kim, Hong-Yeon;Kim, Sun-Bin;Choi, Han-Lim
    • Journal of Coastal Disaster Prevention
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    • v.5 no.4
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    • pp.163-172
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    • 2018
  • To propose the design technique and the execution manual of the LWFS(Lightweight Foamed Soil) method using dredged soil, the operation system for the test-bed integrated management, and to establish an amendment for the domestic quantity per unit and specifications, and a strategy for its internationalization. In order to utilize the dredged soil from the coastal area as a construction material, we constructed the embankment with LWFS on soft ground and monitored its behavior. As a result, it can be expected that the use of LWFS as an embankment material on the soft ground can improve the economic efficiency by reducing the depth and period of soil improvement as well as the uses of nearby dredged soil. To verify the utilization of the dredged soil as a material for light-weighted roadbed, soft ground and foundation ground, and surface processing, perform an experimental construction for practical structures and analyze the behavior. It is expected to be able to improve the soft ground with dredged soil and develop technique codes and manuals of the dredged soil reclamation by constructing a test-bed in the same size of the fields, and establish the criteria and manual of effective dredged soil reclamation for practical use. The application technology of the dredged soil reclamation during harbor constructions and dredged soil reclamation constructions can be reflected during the working design stage. By using the materials immediately that occur from the reclamation during harbor and background land developments, the development time will decrease and an increase of economic feasibility will happen. It is expected to be able to apply the improved soil at dredged soil reclamation, harbor and shore protection construction, dredged soil purification projects etc. Future-work for develop the design criteria and guideline for the technology of field application of dredged soil reclamation is that review the proposed test-bed sites, consult with the institutions relevant with the test-bed, establish the space planning of the test-bed, licensing from the institutions relevant with the test-bed, select a test-bed for the dredged soil disposal area.

Surface Milling for the Study of Pore Structure in Shale Reservoirs (셰일 저류층 내 공극 구조 연구를 위한 표면 밀링)

  • Park, Sun Young;Choi, Jiyoung;Lee, Hyun Suk
    • Korean Journal of Mineralogy and Petrology
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    • v.33 no.4
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    • pp.419-426
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    • 2020
  • Understanding the pore structure including pore shape and connectivity in unconventional reservoirs is essential to increase the recovery rate of unconventional energy resources such as shale gas and oil. In this study, we found analysis condition to probe the nanoscale pore structure in shale reservoirs using Focused Ion Beam (FIB) and Ion Milling System (IMS). A-068 core samples from Liard Basin are used to probe the pore structure in shale reservoirs. The pore structure is analyzed with different pretreatment methods and analysis condition because each sample has different characteristics. The results show that surface milling by FIB is effective to obtain pore images of several micrometers local area while milling a large-area by IMS is efficient to observe various pore structure in a short time. Especially, it was confirmed that the pore structure of rocks with high content of carbonate minerals and high strength can be observed with milling by IMS. In this study, the analysis condition and process for observing the pore structure in the shale reservoirs is established. Further studies are needed to perform for probing the effect of pore size and shape on the enhancement of shale gas recovery.