• Title/Summary/Keyword: 3차원 기구

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A Case Study on the Higher Educational Institute Accreditation System in Australia TEQSA and Hong Kong HKCAAVQ (호주 TEQSA와 홍콩 HKCAAVQ의 고등교육기관 평가인증 사례분석)

  • Kim, Jung-Hee;Jeong, Jinchul;Lee, Hyunmin
    • Korean Journal of Comparative Education
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    • v.28 no.3
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    • pp.49-75
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    • 2018
  • Qualitative management and certification of higher education and higher education programs are important in Australia and Hong Kong. The purpose of the study is to analyze the higher educational Institute accreditation in Australia and Hong Kong and to provide basic data for the domestic evaluation accreditation system For this purpose, the analysis was conducted based on the analysis framework of Kis(2005), which was modified by the researchers in Tertiary Education Quality and Standards Agency(TEQSA) and Hong Kong Council for Accreditation of Academic and Vocational Qualifications(HKCAAVQ). The quality assurance approach in Australia and Hong Kong is common as 'accreditation' and focuses on other evaluation methods, evaluation data, nature of the report, evaluation purpose, evaluation result, and follow-up evaluation. Australia and Hong Kong had separate evaluation agencies for accreditation of higher education qualifications, degrees, and educational programs, and were performing accreditation at the independent institutions. Australia and Hong Kong do not agree with the evaluation standards of higher education institutions because of different academic system and qualifications system from Korea. Higher education institutions need to consider international interchange in terms of exchanging higher education human resources between countries. It is also necessary to conduct evaluation of higher education institutions with reference to higher education quality management standards.

A Study on the behavior of bottom water in water area by using modified POM (개량형 POM을 이용한 수역에서의 저층수의 거동에 관한 연구)

  • Yoon Jong-Sung;Lee Dong-Ken;Kim In-Cheol
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.18 no.3
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    • pp.198-210
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    • 2006
  • POM(Princeton Ocean Model) was utilized in this study because it took ${\sigma}-coordinate$ system which could predict the behavior of bottom water. The model has been increasingly applied to costal area although it was initially developed as the ocean flow model. The original POM did not correct computational errors in transformation of ${\sigma}-coordinate$ system. The trying to reduce conversional errors might improve accuracy of flow velocity in vicinities of bottom layer. Therefore, in this study it was proposed to modify the original POM by using error correction method suggested by $Sl{\Phi}rdal$(1997). The modified POM was applied to Young-rang Lake, one of the typical brackish lakes in Korea. It was found that the behavior of bottom water could be well predicted. Thus, it seems that the modified POM can be used as a useful tool to clarify the mechanism of formation and behavior of bottom water including oxygen-deficient water mass.

Cure Behavior and Thermal Stability of Difunctional/Trifunctional Epoxy Blend System Initiated by Thermal Latent Catalyst (열잠재성 촉매 개시제를 이용한 2관능성/3관능성 에폭시 블렌드계의 경화거동 및 열안정성)

  • Park, Soo-Jin;Kim, Taek-Jin;Lee, Jae-Rock
    • Applied Chemistry for Engineering
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    • v.10 no.7
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    • pp.1046-1051
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    • 1999
  • Cure behavior and thermal stability of the different ratio of diglycidylether of bisphenol A(DGEBA)/trimethylolpropane triglycidylether(TMP) epoxy blends initiated by 1 wt % N-benzylpyrazinium hexafluoroantimonate (BPH) as a cationic latent catalyst were studied using DSC and TGA, respectively. Latent properties were performed by measurement of the conversion as a function of temperature using dynamic DSC. Dynamic DSC thermograms of DGEBA/TMP blends revealed that the weak peak was formed by complex formation between the hydroxyl groups in DGEBA and BPH, and between epoxides and BPH in low temperature ranges. The strong peak was considered as an exothermic reaction by the formation of three-dimensional network in high temperature ranges. Isothermal DSC revealed that the reaction rate of the blends was found to be higher than that of the neat TMP. The thermal stabilities in the cured resins were increased with increasing the DGEBA content. These results could be interpreted in terms of the stable aromatic structure, existence of hydroxyl group and high molecular weight of DGEBA.

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Flying Characteristics of Running Tape above Rotating Head (II) -Experimental Analysis- (회전헤드에 대한 주행테이프의 부상특성 (II) -실험해석-)

  • 민옥기;김수경
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.1
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    • pp.107-119
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    • 1991
  • This dissertation analyzes the running mechanism of flexible and thin tape above rotating head through the experiment. The scope of study is confined to measure the vertical deformation of running tape under hydrodynamic pressure invoking phenomena of elasto-hydrodynamic lubrication between the protruded bump on a rotating cylinder ad the running tape. Experimental system is devised to measure the vertical deflection of the running tape by opto-electronical displacement gauge, which enables to detect microscopic surface deflection of high frequency. Thorough the tests of small specimens of groove and bump, the accuracy and reliability of this experimental method is confirmed and achieved an accuracy within 5%(2.mu.m) error for the microscopic deflection with high frequency. In experimental works, the effects of bump size on flying characteristics of the tape were evaluated and examined. For the vertical deformation of the running tape. the numerical results and its trend agree qualitatively with the experimental ones.

NUMERICAL ANALYSIS OF THE HYDROGEN-STEAM BEHAVIOR IN THE APR1400 CONTAINMENT DURING A HYPOTHETICAL TOTAL LOSS OF FEED WATER ACCIDENT (APR1400의 급수완전상실사고 시 격납건물 내에서 수소와 수증기의 3차원 거동에 대한 수치해석)

  • Kim Jongtae;Hong Seong-Wan;Kim Sang-Baik;Kim Hee-Dong
    • Journal of computational fluids engineering
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    • v.10 no.3 s.30
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    • pp.9-18
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    • 2005
  • During a hypothetical severe accident in a nuclear power plant (NPP), hydrogen is generated by the active reaction of fuel-cladding and steam in the reactor pressure vessel and released with steam into the containment. In order to mitigate hydrogen hazards possibly occurred in the NPP containment, hydrogen mitigation system (HMS) is usually adopted. The design of the next generation NPP (APR1400) designed in Korea specifies 26 passive autocatalytic recombiners and 10 igniters installed in the containment for the hydrogen mitigation. in this study, the analysis of the hydrogen and steam behavior during a total lose of feed water (TLOFW) accident in the APR1400 containment has been conducted by using the CFD code GASFLOW. During the accident, a huge amount of hot water, steam, and hydrogen is released in the in-containment refueling water storage tank (IRWST). The current design of the APR1400 includes flap-type dampers at the IRWST vents which are operated depending on the pressure difference between inside and outside of the IRWST. it was found that the flaps strongly affects the flow structure of the steam and hydrogen in the containment. The possibilities of a flame acceleration and transition from deflagration to detonation (DDT) were evaluated by using Sigma-Lambda criteria. Numerical results indicate the DDT possibility could be heavily reduced in the IRWST compartment when the flaps are installed.

Development of a Micro-CT System for Small Animal Imaging (소 동물 촬영을 위한 Micro-CT의 개발)

  • Sang Chul Lee;Ho Kyung Kim;In Kon Chun;Myung Hye Cho;Min Hyoung Cho;Soo Yeol Lee
    • Journal of Biomedical Engineering Research
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    • v.25 no.2
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    • pp.97-102
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    • 2004
  • We developed an x-ray cone-beam micro computed tomography (micro-CT) system for small-animal imaging. The micro-CT system consists of a 2-D flat-panel x-ray detector with a field-of-view (FOV) of 120${\times}$120 mm2, a micro-focus x-ray source, a scan controller and a parallel image reconstruction system. Imaging performances of the micro-CT system have been evaluated in terms of contrast and spatial resolution. The minimum resolvable contrast has been found to be less than 36 CT numbers at the dose of 95 mGy and the spatial resolution about 14 lp/mm. As small animal imaging results, we present high resolution 3-D images of rat organs including a femur, a heart and vessels. We expected that the developed micro-CT system can be greatly used in biomedical studies using small animals.

Initial Reactions of Ti on the Atomically Clean Si Substrates (초청정한 Si 기판 위에서 Ti의 초기 반응)

  • Jeon, Hyeongtag;Nemanich, R.J.
    • Analytical Science and Technology
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    • v.5 no.3
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    • pp.303-308
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    • 1992
  • Initial reactions of Ti and Si have been studied to examine the surface roughness of titanium silicide. Formation mechanism has been explored with in-situ measurement tools such as AES(Auger electron spectroscopy) and LEED (low energy electron diffraction). One or two monolayers of Ti films have been deposited in ultrahigh vacuum on atomically clean Si(111) substrates. Atomically clean Si substrates which are reconstructed $7{\times}7$ Si(111) have been obtained after in-situ heat cleaning in ultrahigh vacuum. Deposition of the films were monitored by a quartz cuystal oscillator and the Ti films were analyzed with in-situ AES and LEED. The in-situ measurements show that the initial reactions of Ti and Si occur at room temperature and form a disordered layer. At low temperatures($200^{\circ}C{\sim}300^{\circ}C$) intermixing of Ti and Si is detected by AES. Substrate $1{\times}1$ LEED patterns are displayed after $400^{\circ}C$ anneal. This indicates that the disordered layer has transformed to form an ordered surface. The reappearance of the $7{\times}7$ LEED pattern in observed with further high temperature anneals and indicates three dimensional titanium silicide island formation.

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Growth mechanism of three dimensionally structured TiO2 thin film for gas sensors (가스 감응용 3차원 구조체 TiO2 박막 성장기구)

  • Moon, Hi-Gyu;Yoon, Seok-Jin;Park, Hyung-Ho;Kim, Jin-Sang
    • Journal of Sensor Science and Technology
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    • v.18 no.2
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    • pp.110-115
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    • 2009
  • Polystyrene (PS) microspheres were used to good advantage as a template material to prepare macroporous $TiO_2$ thin films. This is enabled to run the thermal decomposition of the PS without the collapsing of the 3-D macroporous framework during the calcination step. $TiO_2$ thin films were deposited onto the colloidal templated substrates at room temperature by RF sputtering, and then samples were thermally treated at $450^{\circ}C$ for 40.min in air to remove the organic colloidal template and induce crystallization of the $TiO_2$ film. The macroporous $TiO_2$ thin film exhibited a quasi-ordered partially hexagonal close-packed structure. Burst holes, estimated to be formed during PS thermal decomposition, are seen as the hemisphere walls. the inner as well as the outer surfaces of the hollow hemispheres formed by the method of thermal decomposition can be easily accessed by the diffusing gas species. As a consequence, the active surface area interacting with the gas species is expected to be enlarged about by a factor of fourth as large as compared to that of a planar films. Also the thickness at neighboring hemisphere could be controlled a few nm thickness. If the acceptor density becomes as large that depletion width reaches those thickness, the device is in the pinch off-situation and a strong resistance change should be observed.

A Study on the Measurement Accuracy and Linearity of the Mandibular Kinesiograph (Mandibular Kinesiograph의 선형충실도 및 계측정확도에 관한 연구)

  • Kim, In-Kwon
    • The Journal of the Korean dental association
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    • v.22 no.7 s.182
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    • pp.607-620
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    • 1984
  • The validity of the Kinesiegraph (MHG-5R) output was studied using a non-ferromagnetic positioning device within working range of a 3 cm wide by 4 cm deep by 5 cm high three dimensional lattice. To determine how well observed values of the M K G outputs may predict case values of actual measurements, relationships between those values were tested by viewing scatter plots and correlation between observed values and actual values. In order to devise some form of served values of the M k G outputs (volts), statistical regression analysis was performed. The statistical analysis showed that observed values and actual values were strongly correlated. However, high correlation does not necessarily mean perfect predictability of given linear models. The formulated models were not able to predict all of acutal values this is partly 엳 새the discreteness of dependent variables (actual values) and also is because of independent nature of observed values. In conclusion, unless the Kinesiograph is suitably modified, the inherent nonlinearity characteristic of the system output limits its application to the measurement of a limited range of jaw movements.

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Over-Strength of Low-Rise RC Frame in Low Seismic Zone (약지진동 지역의 저층 RC 골조의 초과강도)

  • 이영욱
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.2
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    • pp.9-18
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    • 1999
  • The seismic over-strength factor Ω is evaluated for 4-story reinforced concrete buildings in Korea, which has low seismic intensity. For this study, the seismic load suggested in' Aseismic guideline research- phase ll' (in Korea) is used. When 3D study-models are designed, span length and bay number are varied and accidental torsional moment is considered. And the models are analyzed by push-over analysis, in which external and internal frame are connected by rigid-link. As a result of numerical experiments, Ω is increased as the bay number or span length is increased. Because, by the including of accidental torsional moment in designing process, the increased ratio of strength of external columns is larger than the increased ratio of span length or bay number. And this makes the failure mode of model closer or strong-column and weak-beam mechanism.

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