• Korean Journal of Culture and Social Issue
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• v.23 no.4
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• pp.497-525
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• 2017

This study verified whether university students of Gwangju and Jeollanam-do recall negative information like violence and death faster than positive information like democratic community about the May 18 Gwangju democratic movement in implicit dimension. University students of Gwangju responded faster when the May 18 combined with the pictures of negative content. However, university students of Jeollanam-do responded marginally faster when the May 18 combined with the pictures of positive content. In addition, the students performed implicit evaluation test towards the May 18. The students of Gwangju showed a slightly negative attitude towards the May 18, while the students of Jeollanam-do showed a positive attitude towards the May 18. This study acquires significance because it confirmed that university students of Gwangju have an implicit representation similar to trauma and a terrible feeling about the May 18.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.291-310
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• 2023

This study explores the factors which affect user acceptance for Robo Taxi, an electricity-based Autonomous Vehicles based on a Value based Adoption Model. The three main factors of benefit (usefulness and enjoyment), sacrifice (technicality and perceived fee level), and user experience about mobility services such as car sharing, taxi, and autonomous vehicles, were finally selected as independent variables as a influential factors on perceived values and adoption intention of Robo taxi. The study found that usefulness, enjoyment, and perceived fee had a significant effects on adoption intention, and some user experiences had a significant effect on benefit factors. This study has important implications for incorporating the Value-based Adoption Model results into the service design for the activation of Robo taxi, and furthermore, they can provide a theoretical basis for effective use of the research findings.

• Information Systems Review
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• v.22 no.2
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• pp.1-24
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• 2020

Cloud computing technology is expanding its services to individual consumers through storage and applications. This study aims to compare the predisposing factors that affect the perceived value and the intention to use between users who have used or experienced services and those who have never experienced services from the perspective of benefit and sacrifice based on the value-based acceptance model. The results showed that the sacrifice factor (perceived cost) had a significant effect on perceived value and perceived value had a significant effect on intention to use, but showed a difference in perceived benefit. Perceived usefulness, ubiquity, and network effects had significant impact for experienced users' perceived value, but for inexperienced users, ubiquity did not have significant impact. In addition, usefulness was the most significant factor for experienced users while network effect was the same for inexperienced users. The results of this study suggest that consumers' intention to use personal cloud service is evaluated as a benefit and sacrifice point and a new attempt to re-examine the role of previous experience.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.363-368
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• 2024

Steel structures used in marine environments, such as ships, offshore structures or sub-structures in wind power generation facilities are prone to corrosion. In this study, the corrosion fatigue crack propagation characteristics due to the environmental load are examined by experiment at -1050 mV vs. SCE, which is equivalent to the anti-corrosion potential of zinc anodes that are widely used as sacrificial anodes. In this study, for this purpose, an experimental study is conducted on the effect of cathodic protection on the propagation of fatigue cracks in the seawater environment under the condition of -1050 mV vs. SCE, considering the wave period in synthetic seawater. Cathodic protection prevents corrosion; however, excessive protection generates hydrogen through chemical reactions as well as calcareous deposits. The fatigue crack propagation rate appeared to be faster than the rate in a seawater corrosion environment at the early stages of the experiment. As the crack length and stress intensity factor K increased, the crack propagation rate became slower than the fatigue crack propagation rate in seawater. However, the crack growth rate was faster than that in the atmosphere.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.164-164
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• 2017

해양환경 중 많이 사용되는 철강재료들은 그 가혹한 부식환경에 대응하기 위하여 일반적으로 피복 도장방식법이나 음극방식법이 적용되고 있다. 여기서 음극방식법은 선박 및 해양구조물의 해중부 부식에 대해 가장 효과적인 방식법으로 알려져 있다. 한편, 이와 같이 해수 중 철강재에 음극방식을 적용할 경우, 피방식체인 그 강재 표면에 해수 중 용존된 산소의 음극환원 반응이 일어나며 국부적인 알카리 표면 조건을 형성시켜 $Mg(OH)_2$와 $CaCO_3$의 막을 석출시킨다. 이와같이 음극방식 중 형성된 전착물은 방식해야 될 표면적을 감소시켜 방식전류밀도를 감소시키는 효과가 있는 것으로 보고되고 있다. 이렇게 석출된 전착물은 음극표면에 부분적으로 형성되고, 여러 가지 환경 조건 등의 영향을 받아 그 피막의 형성 정도도 가늠하기 어렵기 때문에 음극방식 설계 시 그 정도에 따른 영향을 고려-반영하기가 곤란하다. 또한 이 전착물은 그 형성 메커니즘에 관한 해석이나 강도, 균일한 밀착성, 장기적인 방식효과 및 효율성 등이 아직 충분히 입증되어 있지 않은 실정에 있다. 따라서 본 연구에서는 해수 중 다양한 전착 프로세스에 의해 제작된 전착물의 기간별, 도장코팅 종류별 특성변화를 분석 및 평가하고, 전착물에 의한 희생양극 소모전류 변화 측정 분석을 통해 전착막을 균일하고 치밀하게 형성시키기 위한 최적의 조건을 찾고자 하였다. 또한 석출속도, 밀착성 및 내식특성을 향상시키기 위해 해수 중 기체를 용해시켜 제작한 막의 특성을 분석-평가하였다. 본 연구에 사용된 강 기판은 일반구조용강(KS D 3503, SS400)으로 ${\varnothing}42.7{\times}1,000mm{\times}4.0t$의 형상으로 제작하였다. 인가된 전류밀도는 1, 3 및 $5A/m^2$이고 도장 코팅 종류별 전착 석출물의 형성차이 비교 분석을 위한 실험은 선박 및 해양구조물에 많이 사용되는 Universal Epoxy 도료 2종을 선정하여 진행하였다. 또한 Steel Wire Mesh의 영향을 알아보기 위해 Mesh를 설치하여 실험을 진행하였다. 기간별-도장 종류별 외관관찰, 전착물의 두께 측정, SEM, EDS 및 XRD를 통해 막의 모폴로지, 조성원소 및 결정구조를 분석하였으며, 전착물의 내식성과 내구성을 평가하기 위해 테이핑 테스트(Taping Test) 및 전기화학적 양극분극 시험을 실시하였다. 희생양극 소모율에 대한 전착물의 영향을 확인하기 위해 외부전원을 인가하여 전착 피막을 형성시킨 강 기판에 희생양극을 연결하여 희생양극 소모효율 측정 시험을 진행하였다. 전착물의 석출량은 시간 및 전류밀도의 증가에 따라 비례하여 증가하였으며, 음극전류 인가 시 금속과 용액 계면 사이의 확산층에서 발생한 $OH^-$ 이온으로 인해 금속과 용액 계면 사이 pH가 부분적으로 증가하여 $Mg(OH)_2$ 화합물이 많이 생성되는 것으로 확인되었다. 또한 Mesh의 부착으로 평활하지 않게 형성된 미세한 굴곡구조 및 표면적 증가로 인하여 단계적으로 피복되는데 필요한 시간이 지연되면서 $CaCO_3$에 비해 $Mg(OH)_2$ 화합물이 상대적으로 증가한 것으로 사료된다. $CaCO_3$(Aragonite) 구조는 견고한 피막으로 치밀하고 화학적 친화력이 높아 우수한 밀착성을 보였으며 전착물의 영향으로 양극 전류가 감소하였고, 이로인해 방식전류 절감효과를 얻을 수 있을 것으로 기대된다.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.6
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• pp.573-580
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• 2004

The main goal of this study was to develop a micro-fabrication process for the capacitive micromachined ultrasonic transducer (cMUT). In order to achieve this goal, the former research results of the micro-electro-mechanical system (MEMS) process for the cMUT were analyzed. The membrane deposition, sacrificial layer deposition and etching were found to be a main process of fabricating the cMUT. The optimal conditions for those microfabrication were determined by the experiment. The thickness, uniformity, and residual stress of the $Si_3N_3$ deposition which forms the membrane of the cMUT were characterized after growing the $Si_3N_3$ on Si-wafer under various process conditions. As a sacrificial layer, the growth rate of the $SiO_2$ deposition was analyzed under several process conditions. The optimal etching conditions of the sacrificial layer were analyzed. The microfabrication process developed in this study will be used to fabricate the cMUT.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.12
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• pp.704-715
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• 2004

Recently, a single or multi processor system uses the hierarchical memory structure to reduce the time gap between processor clock rate and memory access time. A cache memory system includes especially two or three levels of caches to reduce this time gap. Moreover, one of the most important things In the hierarchical memory system is the hit rate in level 1 cache, because level 1 cache interfaces directly with the processor. Therefore, the high hit rate in level 1 cache is critical for system performance. A victim cache, another high level cache, is also important to assist level 1 cache by reducing the conflict miss in high level cache. In this paper, we propose the advanced high level cache management scheme based on the processor reuse information. This technique is a kind of cache replacement policy which uses the frequency of processor's memory accesses and makes the higher frequency address of the cache location reside longer in cache than the lower one. With this scheme, we simulate our policy using Augmint, the event-driven simulator, and analyze the simulation results. The simulation results show that the modified processor reuse information scheme(LIVMR) outperforms the level 1 with the simple victim cache(LIV), 6.7% in maximum and 0.5% in average, and performance benefits become larger as the number of processors increases.

• Journal of Life Science
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• v.29 no.8
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• pp.879-887
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• 2019

This study investigated the localization and changes in the concentration of injected mercury in the kidney, liver, and spleen of mice. To evaluate changes in the concentration of mercury over time, the mice were euthanized 10, 150, and 300 days post-treatment. Localization of accumulated mercury was identified by the autometallography method. Mercury was densely located in the supranuclear cytoplasm of epithelial cells of proximal tubules of the kidney but was not detected in the glomerulus 10 days post-treatment. In the liver, mercury was mainly found in hepatocytes around the portal vein and in sinusoidal Kupffer cells 10 days post-treatment. Mercury was scattered throughout both white and red pulp of the spleen 10 days post-treatment. In terms of changes in the concentration of mercury, the levels were lower in the renal cortex and medulla 150 and 300 days post-treatment as compared with those 10 days post-treatment. Mercury was found at low concentrations in liver hepatocytes 150 and 300 days post-treatment. The mercury concentration was also low in both the white and red pulp of the spleen 150 and 300 days post-treatment. Therefore, the concentrations of accumulated mercury in the kidney, liver, and spleen 150 and 300 days post-treatment were lower than those 10 days post-treatment. We identified the localization of mercury in cells and tissues of several organs and observed that accumulated mercury in organs decreased naturally over time.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.1
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• pp.1-12
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• 2024

Purpose: To histologically evaluate the effects of three calcium silicate-based sealers on rat mandible tissue. Materials and Methods: Rats were randomly divided as follows: A group that sacrificed immediately after cavity preparation, a group that sacrificed two weeks after cavity preparation, a group that sacrificed two weeks after CeraSeal (CS), AH Plus Bioceramic (AHB), or One-Fil (OF) sealer injection, respectively. After tissue processing for all groups, the bone tissue area (%) and the number of osteoclasts in and around the cavity were measured under a microscope. The results of each group were compared and statistical analysis was performed using one-way ANOVA and Tukey's test. Results: The formation of bone tissue and the presence of osteoclasts in the cavity were observed in the group that sacrificed two weeks after cavity preparation and the group sacrificed two weeks after AHB sealer injection, and these groups showed significantly higher average bone tissue area (%) than the other groups. In the other groups, no inflammation or foreign body reaction occurred in the cavity, and no osteoclasts were observed. Conclusion: All calcium silicate-based sealers used in this study showed a favorable bone tissue response when injected into the rat mandible. In particular, higher bone formation in the cavity was observed in AHB.

• Venture DIGEST
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• s.108
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• pp.46-46
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• 2007

마음 깊이 두고 조금씩 실천해가는‘부지런함과 희생’의 결과는 뭘까? 여기 그 과정을 보여주는 기업이 있다. 독자적 기술로 만든 컴퓨터 운영체계를 갖고 싶어 연구를 시작했고 그 속에서 많은 어려움을 겪었지만, 현재를 있게 한 열정과 패기에 SVI의 노하우와 경험을 더해 더욱 새롭고 알찬 미래를 그리는 스노드롭소프트(대표 이상언)를 만났다.