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Study on Running Safety of EMS-Type Maglev Vehicle Traveling over a Switching System (상전도흡인식 도시형 자기부상열차의 분기기 주행안전성 연구)

  • Han, Jong-Boo;Lee, Jong Min;Han, Hyung-Suk;Kim, Sung-Soo;Yang, Seok-Jo;Kim, Ki-Jung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.11
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    • pp.1309-1315
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    • 2014
  • The switch for a maglev vehicle should be designed such that the vehicle safely changes its track without touching the guiderail. In particular, a medium-to-low-speed EMS -type maglev train relies heavily on a U-type electromagnet where it generates levitation force and guidance force simultaneously. Therefore, it is necessary to evaluate the safety of the vehicle whenever it passes the switch, as it lacks active control of the guidance force. Furthermore, when the vehicle passes a segmented switch, which is a group of curves made up of connected lines with a small radius of curvature, it may come into mechanical contact with the guiderail owing to the excessive lateral displacement of the electromagnet. The goal of this study is to analyze the influence of a segmented switch on the safety of major design-related variables for achieving improved running safety. We propose a three-dimensional multibody dynamics model composed of two cars with one body. Using the proposed model, we perform a simulation of the lateral air gap, which is one of the measurements of the running safety of the vehicle when it passes the switch. The analyzed design variables are the length between short span girder, the articulation angle, the length between two centers of a fixed girder at its ends, and the number of girders. On the basis of the effects of the considered design variables, we establish an optimized design of a switch with improved safety.

Analysis of Science Items of the Japanese National Center Test for University Admissions (일본 대학입시센터시험 이과 문항 분석)

  • Kim, Hyun-Kyung;Kim, Dong-Young;Choi, Hyuk-Joon;Ku, Ja-Ok;Dong, Hyo-Kwan;Shin, Il-Yong;Lee, Yang-Rak
    • Journal of The Korean Association For Science Education
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    • v.30 no.4
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    • pp.452-471
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    • 2010
  • As the Korean College scholastic Ability Test (CSAT) has been implemented for 17 years since 1994, it is becoming more and more difficult to make new items that haven't been previously used to measure students' thinking ability. Therefore, it is necessary to keep conducting research on making new test items that can measure students' scholastic ability reliably. For this reason, multiple choice items on the Japanese university entrance exam, which is a Japanese National Center Test for University Admissions (NCTUA) equivalent of CSAT, were analyzed in order to draw implications for CSAT item development. In this study, we analyzed the Japanese NCTUA administered in January 2009 to investigate the structure of its science test. We also analyzed the NCTUA items by the domains of contents and behaviors, and tried to predict item difficulty from the perspective of Korean applicants. Major findings are as follows: Most NCTUA items measure understanding knowledge or low level thinking ability. Also the alloted time for each item is longer than CSAT. The number of test items, and the number of choice and alloted points for each item are diverse, unlike CSAT. The number of items using real-life materials are much more, but the items are not rigorous in sentence expression compared to CSAT. And the difference of difficulty level among science tests were larger with reference to CSAT. Also science score is required for most applicants regardless whether they are taking liberal arts or going onto the science track.

Geochemical Study on the Genesis of Chuncheon Nephrite Deposit (춘천 연옥의 기원에 관한 지구화학적 연구)

  • 박계현;노진환
    • The Journal of the Petrological Society of Korea
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    • v.9 no.2
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    • pp.53-69
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    • 2000
  • To reveal the origin of the Chuncheon nephrite deposit, radiogenic isotopes of Sr and Pb, stable isotopes of 0 and H, and rare earth elements concentrations were analyzed. Such geochemical data were integrated to track the stepwise changes during the various ore formation stages. All the samples from the nephrite deposit have significantly low 0 isotopic ratios compared with the marble from which they had been formed, which reflects the very important role of the crustal circulating water with low 6180 and 6D in every stage of ore formation. There were progressive decrease of 6180 and 6D during the genesis of Chuncheon nephrite deposit. Newly formed minerals during the ore formation reveal disequilibrium with existing minerals in the respect of 0 isotope, which suggests that the ore-forming fluid of circulating water origin was involved with significant water-rock ratios in every step of ore formation process. The ore samples have Sr and Pb isotopic ratios similar to the values of Kyeonggi gneiss complex within which the deposit is located, which also suggests the important role of crustal circulating water in the genesis of the deposit. In conclusion, all the geochemical data support that major portion of the ore-forming fluid of Chuncheon nephrite deposit was derived ultimately from the surface water of meteoric origin. The meteoric water supplied Sr and Pb through leaching the rocks surrounding the ore deposits.

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Overview of new developments in satellite geophysics in 'Earth system' research

  • Moon Wooil M.
    • 한국지구물리탐사학회:학술대회논문집
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    • 2004.06a
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    • pp.3-17
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    • 2004
  • Space-borne Earth observation technique is one of the most cost effective and rapidly advancing Earth science research tools today and the potential field and micro-wave radar applications have been leading the discipline. The traditional optical imaging systems including the well known Landsat, NOAA - AVHRR, SPOT, and IKONOS have steadily improved spatial imaging resolution but increasing cloud covers have the major deterrent. The new Earth observation satellites ENVISAT (launched on March 1 2002, specifically for Earth environment observation), ALOS (planned for launching in 2004 - 2005 period and ALOS stands for Advanced Land Observation Satellite), and RADARSAT-II (planned for launching in 2005) all have synthetic aperture radar (SAR) onboard, which all have partial or fully polarimetric imaging capabilities. These new types of polarimetric imaging radars with repeat orbit interferometric capabilities are opening up completely new possibilities in Earth system science research, in addition to the radar altimeter and scatterometer. The main advantage of a SAR system is the all weather imaging capability without Sun light and the newly developed interferometric capabilities, utilizing the phase information in SAR data further extends the observation capabilities of directional surface covers and neotectonic surface displacements. In addition, if one can utilize the newly available multiple frequency polarimetric information, the new generation of space-borne SAR systems is the future research tool for Earth observation and global environmental change monitoring. The potential field strength decreases as a function of the inverse square of the distance between the source and the observation point and geophysicists have traditionally been reluctant to make the potential field observation from any space-borne platforms. However, there have recently been a number of potential field missions such as ASTRID-2, Orsted, CHAMP, GRACE, GOCE. Of course these satellite sensors are most effective for low spatial resolution applications. For similar objects, AMPERE and NPOESS are being planned by the United States and France. The Earth science disciplines which utilize space-borne platforms most are the astronomy and atmospheric science. However in this talk we will focus our discussion on the solid Earth and physical oceanographic applications. The geodynamic applications actively being investigated from various space-borne platforms geological mapping, earthquake and volcano .elated tectonic deformation, generation of p.ecise digital elevation model (DEM), development of multi-temporal differential cross-track SAR interferometry, sea surface wind measurement, tidal flat geomorphology, sea surface wave dynamics, internal waves and high latitude cryogenics including sea ice problems.

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Eco-corridor Positioning for Target Species - By Field Surveying of Mammals' Road-Kill - (목표종 생태통로의 위치선정 -포유류 Road-kill 현장조사를 중심으로-)

  • Lee, Yong-Wook;Lee, Myeong-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.9 no.3
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    • pp.51-58
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    • 2006
  • The purpose of this research presents a method to position and makes the structure for eco-corridors reasonably with collectable analysing results of various effects shown in mammals' road-kill at 429 points. Target animals of this research are Leopard cat, Siberian weasel, Raccoon dog, Korean hare, Eurasian red squirrel, Siberian chipmunk and Water deer. The results derived from the empirical analysis on the contents above are followed. First, according to the results as for Leopard cat road kill analysis, which is designated as Endangered Species Class II, the eco-corridor might be located at near village having stead food in order to decrease the frequencies of road-kill, because its road kill points were mainly collected at 4 lane hilly road with mountain-road-farm area geological type of. Second, because Siberian weasel's road kill was detected at 2 lane hilly road with mountain-road-stream geological type, the eco-corridor might be located at near a mill to decrease road-kill frequencies. Third, the road-kill frequency of Eurasian red squirrel can be reduced when the eco-corridor is located at the area across coniferous tree near 4 lane west sea freeway with mountain-road-mountain. Fourth, the road-kill of Raccoon dog can be reduced when the eco-corridor is located at 4 lane mountain road or hilly road with the geological type having farm land-road-mountain(stream). Fifth, Korean hare's road-kill can be reduced when the eco-corridor is located at grass land across ridge line of mountain, because wild rabbit road kill was happened at 4 lane mountain road or 2 lane mountain road(mountain-road-mountain). Sixth, As for Siberian chipmunk, the eco-corridor might be located at the side slope of mountain road at 2 lane mountain road under the speed of 60km/h with mountain-road-mountain. Seventh, For Water deer, the eco-corridor might be located at 4 lane hilly road with mountain-road-farm land. As for Common otter, Amur hedgehog, Yellow-throated marten, Weasel, it is difficult to specify the proper site of eco-corridor due to the lack of data. Eco-corridors for carnivores might be well located at 4 lane hilly road or 2 lane hilly road with mountain-road-farm land, and the track for herbivores might be well located as a overhead bridge on mountain-road-mountain type across mountains. In order to position eco-corridors for wildlife properly, we have to research animal's behavior with ecological background, and to consider the local uniqueness and regularly collect the empirical road-kill data in long term 3 to 5 year, which can be the foundation for the more suitable place of wild life eco-corridors.

A Study on the Linkage between Intelligent Security Technology based on Spatial Information and other Technologies for Demonstration of Convergence Technology (융복합 기술 실증을 위한 공간정보 기반 지능형 방범 기술과 타 분야 기술 간 연계 방안 연구)

  • Shin, Young-Seob;Han, Sun-Hee;Yu, In-Jae;Lee, Jae-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.622-632
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    • 2018
  • With the recent changes in the social environment, the growth in the so-called 'five major crimes' has been highlighted as one of the causes of anxiety in Koreans' lives. Many attempts have been made to solve this problem; however, it is still difficult to secure the location information of the socially vulnerable in emergency situations and to precisely identify the features and clothing of criminals and track them using current image analysis technology. Therefore, the development of precision positioning technology and support services along with intelligent security service technology based on spatial information has been given a high priority. This study suggested measures that could be continuously applied to link technologies and services with high linkability by analyzing technologies based on spatial information and other fields. To establish measures for linkage between intelligent security technology and other technologies and services, this study analyzed the existing technologies and research trends in intelligent security technology, and reviewed linkable services according to five criteria established to evaluate their linkability. Based on this analysis, three technologies with high linkability were ultimately selected, and measures for linkage were established. It is expected that the linkage measures derived using the objective evaluation criteria will serve as a stepping stone for promoting active technology linkage and commercialization in the future, even after the completion of this study.

Applied Mineralogy for the Conservation of Dinosaur Tracks in the Goseong Interchange Area (35번 고속도로 고성 교차로 지역 공룡발자국의 보존을 위한 응용광물학적 연구)

  • Jeong Gi Young;Kim Soo Jin
    • Journal of the Mineralogical Society of Korea
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    • v.17 no.3
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    • pp.189-199
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    • 2004
  • Cretaceous sedimentary rocks bearing dinosaur tracks in the Goseong interchange area were studied for their conservation and public display in the aspect of applied mineralogy. Black clay layers alternate with silt layers in the sedimentary rocks. The verical and horizontal fissures are commonly filled with calcite veinlets, supergenetic iron and manganese oxides. The rocks are composed of quartz, albite, K-feldspar, calcite, chlorite, illite, muscovite, and biotite, with minor apatite and rutile. Silt layers are relatively rich in calcite and albite, whereas clay layers are abundant in quartz, illite, and chlorite. Al, Fe, Mg, K, Ti, and P are enriched in the clay layers, while Ca, Na, and Mn in silt. Most of trace elements including V, Cr, Co, Ni, Cs, Zr, REE, Th, and U are enriched in clay layers. Inorganic carbon are present in silt layers as calcite, while organic carbon in black clay layers. The black clay layers were partly altered to yellow clay layers along the fissures, simultaneously with the decrease of organic carbon. Selective exfoliation of clay-rich black and yellow clay layers, calcite matrix of silt layers and calcite infillings of fissures are estimated as the major weakness potentially promoting chemical and physical degradation of the track-bearing rock specimens.

IMPLANT INSTALLATION USING VERTICAL DISTRACTION OSTEOGENESIS AT A SEVERELY ATROPHIED EDENTULOUS MANDIBLE (심하게 위축된 하악골의 완전 무치악 환자에서의 수직 골신장술을 이용한 임플란트 치료)

  • Yeom, Hak-Ryol;Jeon, Seung-Ho;Kim, Yoon-Tae;Paeng, Jun-Young;Ahn, Kang-Min;Myung, Hoon;Hwang, Soon-Jung;Seo, Byoung-Moo;Choi, Jin-Young;Lee, Jong-Ho;Choung, Pill-Hoon;Kim, Myung-Jin
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.2
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    • pp.154-165
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    • 2006
  • Objectives : It is difficult to place implants at a severely atrophied edentulous mandible because of vertical and horizontal alveolar defect. The autogenous and allogenic bone graft and guided bone regeneration are useful, but there are some limitations such as the resorption and infection of the grafted bone, and insufficiency of soft tissue. Distraction osteogenesis has recently evolved a challenging technique to overcome major draws of conventional augmentation procedures, we, therefore, report the four applications of implant placement after vertical alveolar distraction osteogenesis. Patients and Methods : Four patients(all female, mean age: $60{\pm}6$ years) with severe alveolar ridge deficiencies at their anterior mandible were treated with vertical alveolar distraction osteogenesis by intraoral device(Track 1.5, 15 mm model, KLS Martin, Tuttlingen, Germany) and placement of implants (Branemark MK III, TiUnite). After the latency periods of 5, 7, 8 days, distraction rhythm and rate were $0.5\;mm{\times}2\;times/day$ in the case of good bone quality, and $0.25\;mm{\times}3\;times/day$ in the case of poor bone quality. After consolidation periods of mean fifteen weeks, five implants for each patients were placed at the interforaminal area. Results : On average, a vertical gain of $11.38{\pm}1.38\;mm$ was obtained by distraction. And all distraction zone showed complete ossification by panoramic radiography. There were no postoperative complications other than numbness of lower lip in one case. Total twenty implants in four patients were placed and their outcomes were satisfactory. Conclusion : It is a useful method to place five implants after vertical distraction osteogenesis of the severely atrophied mandible for the implant-supported fixed prosthesis.

Analysis of different types of turnovers between winning and losing performances in men's NCAA basketball

  • Han, Doryung;Hawkins, Mark;Choi, HyongJun
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.7
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    • pp.135-142
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    • 2020
  • Basketball is a highly complex sport, analyses offensive and defensive rebounds, free throw percentages, minutes played and an efficiency rating. These statistics can have a large bearing and provide a lot of pressure on players as their every move can be analysed. Performance analysis in sport is a vital way of being able to track a team or individuals performance and more commonly used resource for player and team development. Discovering information such as this proves the importance of these types of analysis as with post competition video analysis a coach can reach a far more accurate analysis of the game leading to the ability to coach and correct the exact requirements of the team instead of their perceptions. A significant difference was found between winning and losing performances for different types of turnovers supporting current research that states that turnovers are not a valid predictor of match outcomes and that there is no specific type of turnover which can predict the outcome of a match as briefly mentioned in Curz and Tavares (1998). Significant differences were found between winning and tied and losing and tied performance for some types of turnovers, however due to the lack of data collected in this area they cannot be considered valid. Further research could also be conducted in other areas relating to performance indicators where there is currently minimal research in some areas such as assisted baskets, stated about the performance indicators in their own study the performance indicators are inadequate for explaining the complexities of the game suggesting that one indicator will not be constant in every game an research into performance analysis areas would be more appropriate.

Progesterone and Estrogen Levels in Holstein Blood and Milk Following Artificial Insemination and Embryo Transfer (인공수정 및 수정란이식 후 젖소의 혈액과 유즙에서 Progesterone과 Estrogen 농도 변화와 수태율과의 상관관계)

  • Han, Rong-Xun;Kim, Hong-Rye;Diao, Yun-Fei;Kim, Young-Hoon;Woo, Je-Seok;Jin, Dong-Il
    • Korean Journal of Agricultural Science
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    • v.37 no.3
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    • pp.393-398
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    • 2010
  • Early pregnancy diagnosis of bovine is an essential component for efficient reproductive plan in farms because long term of non-pregnancy results in economic losses by failure of offspring production and low milk yield in dairy cattle. The major steroid hormones related with reproduction are known to be progesterone and estrogen in bovine pregnancy. To evaluate detection level of hormones in milk, plasma and milk progestrone and estrogen of Holstein cows was analyzed during artificial insemination (AI) and embryo transfer (ET). Progesterone concentration at 21 days postestrus was significantly different in plasma and milk between pregnant and non-pregnant cows. Estrogen concentration at estrus was higher in pregnant recipients than that in non-pregnant recipients. To analyze correlation between hormone levels and conception rates in Holstein, the conception and return rates were checked following AI, and the returned cows were on the track of pregnancy after consecutive AI. Pregnant cows following first AI were considered as high conception group while pregnant cows following third AI were rated as low conception group. Proportion of high and low conception groups in this study was 78.2% and 9.1%, respectively. Hormone analysis indicated that high conception group had higher estrogen level during estrus than low conception group ($26.45{\pm}3.32$ vs $19.017{\pm}2.97$). Progesterone level was not different between high and low conception groups during estrus but increased significantly after 21 days postestrus (21 day: $4.95{\pm}1.12$ vs $0.95{\pm}0.23$, 35 day: $12.47{\pm}3.82$ vs $2.41{\pm}1.21$). In conclusion, the pattern of progesterone and estrogen secretion in Holstein milk samples could be a good candidate for early pregnancy detection and selection of recipients during ET.