• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2585-2593
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• 2020

Swift heavy ion (SHI) beam irradiation can generate desirable defects in materials by transferring sufficient energy to the lattice that favours huge possibilities in tailoring of materials. The effect of Ag¹⁵⁺ ion irradiation with energy 200 MeV on spray deposited V₂O₅ thin films of thickness 253 nm is studied at various ion doses from 5 × 10¹¹ to 1 × 10¹³ ions/㎠. The XRD results of pristine film confirmed orthorhombic structure of V₂O₅ and its average crystallite size was found to be 20 nm. The peak at 394 cm^-1 in Raman spectra confirmed O-V-O bonding of V₂O₅, whereas 917 cm^-1 arise because of distortion in stoichiometry by a loss of oxygen atoms. Raman peaks vanished completely above the ion fluence of 5 × 10¹² ions/㎠. Optical studies by UV-Vis spectroscopy shows decrement in transmittance with an increase in ion fluence up to 5 × 10¹² ions/㎠. The red shift is observed both in the direct and indirect band gaps until 5 × 10¹² ions/㎠. The surface topography of the pristine film revealed sheath like structure with randomly distributed spherical nano-particles. The roughness of film decreased and the density of spherical nanoparticles increased upon irradiation. Irradiation improved the conductivity significantly for fluence 5 × 10¹¹ ions/㎠ due to band gap reduction and grain growth.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.456-456
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• 2013

We report the modifications in the electronic structureof ZnO thin films induced by swift heavy ion (SHI) irradiated ZnO thin films by using near edge X-ray absorption fine structure (NEXAFS) spectroscopy at O K-edge was performed at BL10D XAS-KIST beamline at Pohang Accelerator Lab (PAL). ZnO films of 250 nm thickness oriented in [200] plane deposited by RF magnetron sputtering using equal $Ar:O_2$ atmosphere and air annealed at $500^{\circ}C$ for 6 hours for stability were irradiated with 120 MeV Au and 100 MeV O beams separately with different doses ranging from $1{\times}10^{11}$ to $5{\times}10^{12}$ ions/$cm^2$. High Resolution X-ray diffraction and NEXAFS analysis indicates significant changes in the electronic structure and the SHI effect is different for Ag and O-beams. The NEXAFS measurements provide direct evidence of O 2p and Zn 3d orbital hybridization. The NEXAFS results will be presented in detail.

• Journal of Korea Trade
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• 제27권2호
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• pp.1-21
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• 2023

Purpose - The bank payment obligation is a transaction method that combines the certainty of L/C transactions with the speed of remittance payments, so the main purpose of this study is to highlight the superiority of bank payment obligation, noting the difference between bank payment obligation and L/C transactions. In addition, we would like to examine how bank payment obligations can actually be applied to support various valuable proposals such as post-shipment and post-shipment finance according to the payment process.. Design/methodology - This study focused on literature based on data from ICC and SWIFT along with previous domestic and international studies. In terms of a research method, a literature review was adopted with electronic trade-related books and journals and policy-related reports from international trade-related agencies. Findings - Unlike L/C transaction, BPO transaction verify the data inquiry process based only on the combination result of the established baseline and dataset. Accordingly, it is superior to L/C transaction in that there is no confrontation between the parties over the results of the inquiry, and clear transactions are possible according to the principle of proof after prepayment. In addition, unlike credit transactions, data inconsistency acceptance procedures confirm payment obligations in consideration of importers' intentions. As a result, as long as trade documents are in the hands of exporting countries, flexible document disposition is possible in response to the situation after payment, which is more advantageous than L/C transaction. Originality/value - Specifically, from the importer's point of view, BPO transactions have the advantage of reducing the manpower required to prepare and review trade documents and processing transaction negotiations with exporters advantageously due to the strength of payment obligations. From the perspective of the exporter, it has the advantage of enabling rapid recovery of trade payments and reducing the risk of importer's cancellation of transactions or content change. From the perspective of participating banks, it is possible to strengthen relations with importer and obtain high commission income by increasing the role of bank reduced by reducing L/C transaction.

• 한국방재안전학회논문집
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• 제17권1호
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• pp.17-25
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• 2024

최근 기후 변화로 인한 산림재난(산불, 산사태) 발생 확률이 상승하고 있으나, 산림재난 대응을 위한 정보 제공 시스템은 통합된 접근을 제공하지 못하고 있다. 따라서 본 연구에서는 신속한 대응을 위해 필수적인 재난정보를 일원화된 시스템으로 제공하고자 기초적인 설계안을 제시하고자 하였다. 이를 위해 산림재난 플랫폼 설계를 위한 필수 구성요소를 조사하고, 사례검토를 통해 신속한 대응과 정보 제공이 가능한 플랫폼 가시화 방법 및 자료구축 방법 등을 연구하고 결과를 제시하였다. 이에 국내외 산림재난 대응 플랫폼은 공간 정보를 활용하여 대상지역의 위치별 정보를 제공하는 것으로 확인되었으며, 산림재난 대응 플랫폼을 설계하기 위한 구성요소로는 대상지역에 대한 기후정보를 포함한 산림재난 빅데이터 구축, 재난 단계별 산림재난 통합진단 요소 기술, 그리고 재난지역 맞춤형 안전 케어 서비스 설계가 필요하다는 결론을 도출하였다.

• 한국패류학회지
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• 제29권4호
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• pp.263-272
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• 2013

고랑가리비의 산란을 유도하고 수정난의 발생과 유생의 성장과정을 조사하였다. 산란자극 방법으로 광 자극, 간출 자극, 온도 자극, 그리고 간출 후 온도자극을 수온 $16{\pm}0.5^{\circ}C$에서 각각 실시하였다. 광 자극은 암컷 1마리당 700-900천개, 온도 자극은 700-800천개로 적은 산란량을 보인 반면 간출 자극은 700-1,200천개로 높았으며 간출 자극 후 온도자극이 1,000-1,500천개로 가장 높은 산란량을 보였다. 수정율에 있어 광 자극은 암컷 1마리당 71.7%, 온도자극은 73.4%, 간출 자극이 73.6%이었으며 간출 자극 후 온도자극은 76.3%로 가장 높았으나 자극방법에 따른 수정율의 유의적인 차이는 없었다. 수정란부터 D상 유생으로의 수온별 발생과정을 조사하기 위하여 비이커에 ml당 1,000개의 수정란을 수용하고 각각 $8^{\circ}C$, $12^{\circ}C$, $16^{\circ}C$, $20^{\circ}C$ 및 $24^{\circ}C$에서 D상 유생으로 발생하는 생존율을 광학현미경을 사용하여 30분 간격으로 관찰한 결과, $8^{\circ}C$와 $24^{\circ}C$의 실험군이 4.1%와 3.2%로 생존율이 낮은 편이었으며 $16^{\circ}C$에서 32.7%로 가장 높은 생존율을 보여주었다. 수정란의 크기는 $72{\pm}2.1{\mu}m$, 담륜자 유생은 $103{\pm}3.8{\mu}m$, D상 유생은 $129{\pm}10.4{\mu}m$, 각정기 유생은 $145{\pm}16.8{\mu}m$, 후기 유생은 $197{\pm}13.6{\mu}m$이었으며 528시간 후에 각장 $245{\pm}15.8{\mu}m$의 초기 부착종묘로 성장하였다.

• 설비공학논문집
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• 제7권2호
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• pp.329-340
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• 1995

Basic refrigeration effect and efficiency of a thermoacoustic refrigerator is studied. The refrigerator model for numerical simulation is composed of half wavelength resonator and appropriate stack of plate. Theoretical model for thermoacoustic refrigeration suggested by Swift et. al is adapted for numerical calculation. The model contains arbitrary viscosity effect of the gas filled in the resonator. The wave equation is integrated by using 4-th order Runge-Kutta algorithm to give pressure distribution along the stack of plate. Heat flux and COP are also calculated based on the energy flux equation. By analyzing the numerical simulation results, optimum values of design parameters for thermoacoustic refrigerator are obtained.

• 소성∙가공
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• 제14권4호
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• pp.327-337
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• 2005

In the present work, the two back stress kinematic hardening models are proposed by combining Armstrong-Frederick, Phillips and Ziegler's hardening rules. Simple combination of hardening rules using simple rule of mixtures results in various evolutions of the kinematic hardening parameter. Using the combined hardening models the ultimate back stress fur the present models is also derived. The stress rate is co-rotated with respect to the spin of substructure due to the assumption of kinematic hardening rule in finite deformation regime. The work piece under consideration is assumed to consist of the elastic and the rigid plastic deformation zone. Then, the J2 deformation theory is facilitated to characterize the plastic deformation behavior under various loading conditions. The plastic deformation localization behaviors strongly depend on the constitutive description namely back stress evolution and its hardening parameters. Then, the analysis for Swift's effects under the fixed boundaries in axial directions is carried out using simple shear deformation.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 1999년도 춘계공동학술대회: 지식경영과 지식공학
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• pp.403-413
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• 1999

Today's businesses are experiencing intensive global competition and the most accelerating pace of change ever. Competitors have sprung up that were not even on the business's radar. This environment impacts all decisions and strategies as business try to dominate their market or their industry merely to survive. So recently most of organizations are considering on building the data warehouse system to pursuit the business intelligence. We need the proper model to guide the approach to plan building data warehouse system when we want to plan it in considering the organizational status. Therefore we suggest a model to decide the approach to build data warehouse considering the project's environmental factors. First we review Ronald S. Swift(1998)'s five environmental factors that we have to consider when planing to build data warehouse. Then we propose a model to decide DW approach by the degree of those factors to be measured. DW approaches in this model are classified in conservative approach, technological approach, increasing approach. enterprise- wide approach, and ideal approach.

• 한국조명전기설비학회지:조명전기설비
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• 제1권1호
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• pp.61-66
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• 1987

이 연구는 주어진 소요배광을 만족시킬 수 있는 조명기구의 광학계의 설계를 다루고 있다. 지금까지 개인적인 경험과 직관에 의지하여 설계가 수행되었고 또한 기존의 CAD algorithm의 경우에도 반사면에서의 확산특성을 무시하였고 CPU time도 상당히 긴 편이었다. 이러한 한계점들을 극복하기 위하여 새로운 CAD algorithm을 제시하였다. 이 새로운 algorithm은 높은 효율과 적절한 조도분포를 제공하는 설계를 간편하고 바르게 수행할 수 있다.

• 천문학회보
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• 제40권2호
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• pp.51.3-52
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• 2015

Gamma-Ray Bursts(GRBs) are the most violent event in the universe, whose detection rate is a few in a day. The spectral lag, which is commonly observed in the observed light curves of GRBs, is a difference in arrival times of the high-energy and low-energy photons. The relation between the spectral lag and the luminosity of the observed GRBs is shown to be anti-correlated in previous studies. In reported relations to date, the isotropic luminosity has been assumed. On the other hand, GRBs are likely to emit its energy through a beamed jet. In this study, we attempt to obtain the relation between the spectral lag and the collimation-corrected luminosity. We have calculated collimation-corrected luminosities and opening angles using the observed light curves taken from a database of Swift/BAT, XRT. We expect to increase its significance level by expanding a sample size compared with those previously analyzed.