• 농촌계획
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• 제9권3호
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• pp.41-46
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• 2003

The study was focused on setting priority for future core technologies in rural development and resources using AHP. The technologies were derived by Delphi method. Evaluation criteria for the priority setting were decided as 'technology', 'market oriented', and 'public concerns' by council. The future core technologies were divided as four groups by importance and R&D level. Technologies in upper two groups were considered in the study. Group I had high importance and high R&D level. Group II had high importance and lower R&D level. Questionnaires were given to 9 specialists in agricultural resources. As the results, 'public concerns' was decided as a most important evaluation criterion. The most important technologies are "technology developing for animal feces and urine treatment, and restoration it to farm land" in group I, and "technology developing for agricultural by-products as energy source" in group II.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1775-1782
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• 2023

Several reactor physics commissioning experiments were conducted to obtain the neutronic parameters at the beginning of the G.A. Siwabessy Multi-purpose Reactor (RSG-GAS) operation. These parameters are essential for the reactor to safety operate. Leveraging the experimental data, this study evaluated the calculated core reactivity, control rod reactivity worth, integral control rod reactivity curve, and fuel reactivity. Calculations were carried out with Serpent 2 code using the latest neutron cross-section data ENDF/B-VIII.0. The criticality calculations were carried out for the RSG-GAS first core up to the third core configuration, which has been done experimentally during these commissioning periods. The excess reactivity for the second and third cores showed a difference of 510.97 pcm and 253.23 pcm to the experiment data. The calculated integral reactivity of the control rod has an error of less than 1.0% compared to the experimental data. The calculated fuel reactivity value is consistent with the measured data, with a maximum error of 2.12%. Therefore, it can be concluded that the RSG-GAS reactor core model is in good agreement to reproduce excess reactivity, control rod worth, and fuel element reactivity.

• 천문학회보
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• 제45권1호
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• pp.30.2-31
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• 2020

We present the properties of circumnuclear gas associated with the AGN located in the center of Abell 1644-South. A1644-S is the main cluster in a merging system, which is also known for gas sloshing in its core as seen in X-ray. The X-ray emission of A1644-S shows a rapidly declining profile, indicating the presence of cooling gas flow. This flow of cool gas may fuel the supermassive black hole embedded in the brightest cluster galaxy, leading to the activation of the central AGN. Indeed, we find a parsec-scale bipolar jet feature in the center of A1644-S in our recent KaVA observation, which implies that its central AGN is likely to have been (re)powered quite recently. In order to verify the hypothesis that cooling gas flow in the cluster core can (re)activate the central AGN, we probe the cold gas properties of the central 1 kpc region of A1644-S using the archival VLA and ALMA data. Based on the spatially resolved morphology and kinematics of HI and CO gas, we challenge to identify inflow/outflow gas streams and clumps. We study the role of circumnuclear cool gas in fueling the centrally located cluster AGN in the cool-core environment. We also discuss how the feedback due to the (re)powered AGN affects the surrounding medium.

• 생명과학회지
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• 제17권9호통권89호
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• pp.1177-1181
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• 2007

칼모둘린은 칼슘과 결합하는 센서로써 다양한 칼모둘린 결합 단백질들과의 상호 작용을 통하여 세포 내에서 여러가지 기능을 조절한다. 진핵 생물들은 많은 종류의 칼모둘린 결합 단백질을 가지고 있기 때문에 이러한 단백질들의 분리와 특성 규명이 중요하다. 이미 여러 가지 방법들을 이용하여 칼모둘린 결합 단백질들이 분리되었고 이미 알려진 단백질의 구조적인 유사성을 토대로 더 많은 단백질들이 예측되었다. 우리는 애기장대에서 칼모둘린 결합 단백질의 분리와 특성 규명을 위해 형광 단백질과 융합된 칼모둘린 과발현 형질 전환체를 제조하여 공촛점 현미경과 Western blot 을 이용하여 과발현 형질 전환체를 선별하였다. 또한 형질 전환체 내의 칼모둘린이 칼모둘린 결합 단백질과 상호 작용함을 pull-down 분석을 통해서 확인하였다. 이러한 결과들을 토대로 칼모둘린 과발현 형질 전환체를 이용하여, 칼모둘린과 상호 작용하는 여러 가지 칼모둘린 결합 단백질들을 분리할 수 있을 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.115-117
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• 2007

Core loss form a larger proportion of the total losses. This paper deals with the analysis on the core loss in PM generator considering the operating speed for wind power application. Using the data information from a manufacturer and nonlinear curve fitting, this paper investigates the magnetic behavior and its core losses in the stator core using the electrical steels.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1309-1314
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• 2014

The measurement of stator core loss for an induction motor at each manufacturing process is carried out in this paper. Iron loss in the stator core of induction motor changes after each manufacturing process due to the mechanical stress, which can cause the deterioration of the magnetic performances. This paper proposes a new iron loss measuring system of the stator core in an induction motor, which can be applied to the case when the distribution of magnetic flux density is not uniform along the magnetic flux path. In the system, the iron loss is calculated based on the induced voltage of the B-search coil and exciting current.

• Journal of the korean society of oceanography
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• 제38권2호
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• pp.45-51
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• 2003

Recent observations reveal that the Tsushima Current has a double-cored structure downstream of the Tsushima Island. To explain this, a simple analytical model is proposed based on the assumption of small lateral eddy viscosity. This model suggests that an otherwise uniform current becomes to have a stream core immediately after it enters a channel due to the action of lateral friction. The core is initially broad but becomes sharper downstream. The speed at which the core develops depends on the intensity of lateral eddy viscosity. Likewise, a single-cored stream changes rapidly to a double-cored stream when it passes through an island located in the center of the channel. When the stream leaves the island behind, the reverse process from the double-to single-cored structures takes place. In this case, however, the double-cored structure is retained for a significant distance from the island. Overall, this model suggests that the double-cored structure of the Tsushima Current observed downstream of the Tsushima Island Is created by the lateral friction exerted by the Tsushima Island.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.3106-3116
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• 2022

The present work presents analysis results of the core design optimizations for an annular, prismatic High Temperature Gas-cooled Reactor (HTGR) with passive decay-heat removal features. Its thermal power is 100 MW_t and the operating temperature is 850 ℃ (1123 K). The neutronic calculations are done for the core with heterogeneous distribution of fuel and burnable poison particles (BPPs) to flatten the reactivity swing and power peaking factor (PPF) during the reactor operation as well as for control rod (CR) insertion into the core to restrain a small excess reactivity less than 1$. The next step of the study is done for evaluation of core reactivity coefficient of temperature.

• Journal of Ceramic Processing Research
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• 제13권spc2호
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• pp.363-367
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• 2012

DLC (diamond liked carbon) coating of the tungsten carbide (WC) alloy core surface for molding a glass aspheric lens improves the quality of glass lens and the molding core and is characterized by high hardness, high elasticity, abrasion resistance and chemical stability. In this study, the effect of DLC coating of a thin film by means of the filtered AIP (arc ion plating) technique was examined on Ra and shape of the coated surface. Roughness before and after DLC coating was measured and the result showed that the roughness was improved after coating as compared to before coating. It was observed that DLC coating of the WC alloy core surface for molding had an effect on improving the roughness and shape of the core surface. It is considered that this will have an effect on improving abrasion resistance and the service life of the core surface.

• 한국분말재료학회지
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• 제15권5호
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• pp.359-364
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• 2008

To satisfy the demand of higher cutting performance, mechanical properties with tungsten carbide (WC-Co) tool materials were investigated. Hardness and transverse rupture strength with WC grain size, Co content and density were measured. Compared to H, K, and S manufacture maker as tungsten carbide (WC-Co) tool materials were used for high-speed machining of end-milling operation. The three tungsten carbide (WC-Co) tool materials were evaluated by cutting of STD 11 cold-worked die steel (HRC25) under high-speed cutting condition. Also, tool life was obtained from measuring flank wear by CCD wear measuring system. Tool dynamometer was used to measure cutting force. The cutting force and tool wear are discussed along with tool material characteristics. Consequently, the end-mill of K, H manufacture maker showed higher wear-resistance due to its higher hardness, while the S maker endmill tool showed better performance for high metal removal.