• The korean journal of orthodontics
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• v.33 no.5 s.100
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• pp.323-337
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• 2003

This study was performed to establish Korean soft tissue cephalometric norms, to compare the norms between sexes and between races, and then to suggest a guideline to execute orthodontic diagnosis and treatment planning for dentofacial deformities in Korean. Young Korean adults were selected. They were 27 males $(23.8{\pm}2.6-year-old)$ and 20 females $(22.5{\pm}1.7-year-old)$ who had harmonious facial balance. After taking lateral cephalograms under the natural head position which is widely known as a highly reliable and reproducible reference position, films were traced and analysing factors were measured as introduced by Arnett et at. Comparisons were done between male and female groups and between Korean and Caucasian groups using unpaired t-test. From the results it was concluded that Korean male had generally thicker lower facial soft tissue and smaller nasolabial angle, longer facial height, deeper facial depth, and more protrusive lower face than Korean female. From the comparison with Caucasian norms adopted from the research of Arnett et al., both Korean male and female showed longer facial lengths generally except less exposed maxillary incisor, and shorter facial depth than Caucasian counterparts. Also, both races showed similar horizontal position of maxillary structures from TVL (true vertical line), but there were more significant anteroposterior differences of marilla-mandible in Korean groups. These results mean Korean had relatively more retruded mandibular structures from the reference line, TVL. Individuals who had harmonious facial balance showed similar facial angle, more or less 170 degree, regardless of sexes or races.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.4
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• pp.294-303
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• 2005

This paper describes the analysis results of a series f Round-Robin test that was performed to intercompare inspection and diagnosis techniques for characterization of pressure tube f a pressurized heavy water reactor under the Coordinated Research Project(CRP) of IAEA's nuclear Power Programme. For this test, six nations, Korea, Canada, India, Argentina, Rumania, and China that currently have pressurized heavy water reactors under operation involved, and the "KOR-1" pressure tube sample prepared by Korea was used. Two kinds of NDE technique, ultrasonic and eddy current test, were applied for these tests. The "KOR-1" pressure tube sample contains total 12 artificial flaws such as crack-like EDM notches, wear that is similar to the real flaws and can be produced on the pressure tubes during plant operation. Test results showed that seven laboratories from six nations detected all twelve flaws in "KOR-1" specimen by using ultrasonic and eddy current test methods, and ultrasonic test method was more accurate than eddy current test method in flaw detectin and sizing. ID flaws in pressure tube sample were more easily detected and accurately sized than OD flaws.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.380-388
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• 2016

Using the magnet gear, it is possible to transmit power without mechanical contact. As the drive shaft in a magnet gear-based speed reducer system is isolated from the drive shaft, the system is a two-inertia resonance system that should cope with an external load with the limited air-gap stiffness. On the other hand, the drive shaft or low-speed side is controlled only by the torque of the drive shaft through an air-gap, and the excessive oscillation or the slip can then be generated because of an abrupt disturbance that is different from the general mechanical gear system. Therefore, the disturbance loaded at the low speed side should be measured or estimated, and considered in the control of the driving shaft. This paper proposes a novel full-state feedback controller with a reduced-order observer for the speed reducer system using a magnet gear with a unified harmonic modulator. The control method was verified by simulation and experiment. To estimate the load at the low speed side, a novel observer was designed, in which the new state variable is introduced and the new state equation is formulated. Using a full-state feedback controller including the observer, the test result against disturbance was compared with two D.O.F PI speed controllers. The pole slip was compensated within relatively a short time, and the simulation result about the estimated variable shows a similar tendency to the test result. The test results showed that the magnet gear-based reducer can be applied to an accurate servo system.

• KDI Journal of Economic Policy
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• v.36 no.1
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• pp.43-80
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• 2014

This study suggests a model for calculating total benefit rigorously to use the contingent valuation method (CVM) in cost-benefit analysis (CBA). Estimating households' willingness to pay through survey method, the study attempts to demonstrate if a respondent's income and the distance between a respondent's residence and the location of a target facility affect her willingness to pay. The estimation results from a structural model show that income and distance-decay effects exist and that the calculated total benefit varies largely when these effects are ignored. The study emphasizes the effects of income and distance-decay on the total benefit must be carefully considered in using CVM for CBA. Even though the total project cost is precisely estimated, the benefit/cost (B/C) ratio may differ largely when the total benefit is not correctly calculated. Also, an ad hoc model generates significantly different estimates from the utility difference model this study adopted. The difference in estimates suggests that the total benefit has to be estimated by a structural model. Finally, simulations are performed to check the validity of the model as well as to predict consequences when income and distance-decay effects are not properly treated. The results from simulations reveal it is not desirable to ignore those effects considering the perspectives of balanced regional development.

• Journal of Korea Water Resources Association
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• v.45 no.2
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• pp.217-227
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• 2012

This paper presents a quasi-steady model for numerical simulations of reservoir sedimentation and reservoir flushing. The quasi-steady model is based on the assumption that the flow is steady with time-dependent stream morphology change. This is reasonable because stream morphology changes over a long period, while the flow changes rapidly. The proposed model is first applied to two laboratory experiments for reservoir sedimentation. The channel is shown to be adjusted to new sediment supply at the upstream by changing both the flow depth and slope. Simulated water surface and bed profiles compare favorably to measured data. The model is also applied to reservoir flushing. Good agreement between simulated and measured data is not obtained due to time variation of outflow generated to facilitate the flushing in the experiment. Finally, relationships for equilibrium flow depth and bed slope are proposed and tested through numerical experiments.

• Journal of KIISE:Databases
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• v.37 no.2
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• pp.113-120
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• 2010

XML is broadly using for data storing and processing. XML is specified its structural characteristic and user can query with XPath when information from data document is needed. XPath query can process when the tern and structure of document and query is matched with each other. However, nowadays there are lots of data documents which are made by using different terminology and structure therefore user can not know the exact idea of target data. In fact, there are many possibilities that target data document has information which user is find or a similar ones. Accordingly user query should be processed when their term usage or structural characteristic is slightly different with data document. In order to do that we suggest a XML document ranking method based on path similarity. The method can measure a semantic similarity between user query and data document using three steps which are position, node and relaxation factors.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.517-520
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• 2009

본 연구에서는 비선형 FEM 해석을 이용하여 PSC(Prestressed concrete)와 강으로 구성된 혼합구조 보의 휨 실험을 검증하였다. 혼합구조 보의 거동에 가장 큰 영향을 미치는 연결부는 Perfobond rib로 구성된 경우와 스터드로 구성된 경우를 고려하였다. 이종 재료가 접하는 경계면의 상호 작용에 대해 완전합성과 부분합성인 경우를 고려하여 혼합구조 보의 비선형 해석을 수행한 후 해석 결과와 실험 결과를 비교하였다. 하중-처짐관계, 파괴 형상 등의 해석 결과를 실험 결과와 비교한 결과, 부분합성을 고려한 모형이 실험 결과와 유사한 거동을 보였으며 또한 Perfobond rib를 갖는 실험체가 스터드를 갖는 실험체보다 해석 결과와 비교 시 안전측의 결과를 나타냈다.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.563-566
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• 2003

This study was proposed to measure total polyphenols and antioxidant activities from leaves of Stachys sieboldii MIQ. Solvents such as acetone 60%, petroleum ether, ethylacetate, and water were used for this purpose The fraction by ethyl acetate fraction showed the strongest activity by DPPH method and contained much more polyphenols than those by other solvents.

• Vending industry
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• v.8 no.3
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• pp.46-50
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• 2008

자판기 산업의 새로운 비전은 과연 창출될 수 있을까?' 내년도 개최되는 Vending Korea 2009 전시회를 바라보는 업계의 관심이 서서히 고조되고 있다. 지난 2003년 이후 5년여 만에 개최되는 전시회에 관심이 높을 수밖에 없는 이유는 현 자판기 산업계가 유사이례 최악의 시장 부진에 시달리고 있기 때문이다. 이런 상황에서 과연 Vending Korea 2009 전시회가 새롭게 산업에 활력을 부여하고, 불황 타파의 해법을 제시할 수 있기를 바라는 기대가 커지고 있는 것이다. Vending Korea 2009 전시회를 통해 산업계가 총결집해 새로운 성장 동력을 창출하지 못하면 자판기 산업의 미래 역시 불투명해질 수밖에 없다. 이제 과제는 산업계가 총집결해 새로운 성장 동력을 창출하지 못하면 자판기 산업의 미래 역시 불투명해질 수밖에 없다. 이제 과제는 산업계가 온 힘을 다해 성공적인 전시회를 개최하는 일이다. 무엇보다 풍성한 전시회의 아이템을 선보이는 일이 전시회 성패의 관건. 많은 업체들이 참가할 수 있도록 주최 측에서 최선을 다하겠지만 업체들의 자발적인 전시회 참가의욕 고취가 가장 중요한 요인이 된다. 그렇다면 과연 왜 Vending Korea 2009 전시회에 참가를 해야 하는가? 참가를 하지 않으면 후회할 수밖에 없는 Vending Korea 2009의 마법은 무엇인가? Vending Korea 2009에 반드시 참가해야 하는 이유 몇 가지를 살펴봤다.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.143-144
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• 2010

As KCI under U.S.D is impossible to calculate all sections compared P-M Interaction Curve of the circular concrete column under EC2 of limit state design and KCI. Result of the construction, P-M Interaction Curve according to design for standard is about the same. If a covering depth rased, EC2 is better safety than KCI.