• 마이크로전자및패키징학회지
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• 제22권2호
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• pp.11-19
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• 2015

Since CMOS device scaling has stalled, three-dimensional (3-D) integration allows extending Moore's law to ever high density, higher functionality, higher performance, and more diversed materials and devices to be integrated with lower cost. 3-D integration has many benefits such as increased multi-functionality, increased performance, increased data bandwidth, reduced power, small form factor, reduced packaging volume, because it vertically stacks multiple materials, technologies, and functional components such as processor, memory, sensors, logic, analog, and power ICs into one stacked chip. Anticipated applications start with memory, handheld devices, and high-performance computers and especially extend to multifunctional convengence systems such as cloud networking for internet of things, exascale computing for big data server, electrical vehicle system for future automotive, radioactivity safety system, energy harvesting system and, wireless implantable medical system by flexible heterogeneous integrations involving CMOS, MEMS, sensors and photonic circuits. However, heterogeneous integration of different functional devices has many technical challenges owing to various types of size, thickness, and substrate of different functional devices, because they were fabricated by different technologies. This paper describes new 3-D heterogeneous integration technologies of chip self-assembling stacking and 3-D heterogeneous opto-electronics integration, backside TSV fabrication developed by Tohoku University for multifunctional convergence systems. The paper introduce a high speed sensing, highly parallel processing image sensor system comprising a 3-D stacked image sensor with extremely fast signal sensing and processing speed and a 3-D stacked microprocessor with a self-test and self-repair function for autonomous driving assist fabricated by 3-D heterogeneous integration technologies.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.157-157
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• 2022

Plants being sessile are prone to various abiotic challenges, including salinity. Plants generally cope with salt stress by regulating their endogenous NO levels. NO exogenously applied in various forms also successfully impedes the salt stress, but its small size, short half life, and high volatility rate hamper its application in agriculture. NO application via CS as a nanocarrier is an alternate option to ensure the optimal kinetic release of NO for a long period compared to the free NO form. Herein, we synthesized and characterized GSNO-CS NP by ionic gelation of TPP with CS and then reacting with GSH, followed by reaction with NaNO₂ suspension. The synthesized NPs were characterized using non-destructive analytical techniques such as DLS, FTIR, and SEM to ensure their synthesis and surface morphology. NO-release profile confirmed optimal kinetic NO release for 24 h from NO-CS NP as compared to free NO form. The efficiency of NO-CS NP was checked on Arabidopsis plants under salinity stress by gauging the morphological, physiological, and enzymatic antioxidant system and SOS pathway gene expression levels. Overall, the results revealed that NO-CS NP successfully mitigates salinity stress compared to free GSNO. Concluding, the findings provide sufficient experimental evidence for the application of nanotechnology to enhance NO delivery, thus inducing more benefits for the plants under stress conditions by mitigating the deleterious impacts of salt stress on the morphological and physiological status of the plants, and regulating the ions exchange by overexpression of SOS pathway candidate genes.

• 한국공간구조학회논문집
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• 제23권2호
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• pp.19-28
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• 2023

Timber structures are susceptible to moisture, contamination, and pest infestation, which can compromise their integrity and pose a significant fire hazard. Despite these drawbacks, timber's lightweight properties, eco-friendliness, and alignment with current architectural trends emphasizing sustainability make it an attractive option for construction. Moreover, timber structures offer economic benefits and provide a natural aesthetic that regulates building temperature and humidity. In recent years, timber domes have gained popularity due to their high recyclability, lightness, and improved fire resistance. Researchers are exploring hybrid timber and steel domes to enhance stability and rigidity. However, shallow dome structures still face challenges related to structural instability. This study investigates stability problems associated with timber domes, the behavior of timber and steel hybrid domes, and the impact of timber member positioning on dome stability and critical load levels. The paper analyzes unstable buckling in single-layer lattice domes using an incremental analysis method. The critical buckling load of the domes is examined based on the arrangement of timber members in the inclined and horizontal directions. The analysis shows that nodal snapping is observed in the case of a concentrated load, whereas snap-back is also observed in the case of a uniform load. Furthermore, the use of inclined timber and horizontal steel members in the lattice dome design provides adequate stability.

• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1237-1251
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• 2016

Although the horizontal component of an earthquake response can be significantly reduced through the use of conventional seismic isolators, the vertical component of excitation is still transmitted directly into the structure. Records from instrumented structures, and some recent tests and analyses have actually seen increases in vertical responses in base isolated structures under the combined effects of horizontal and vertical ground motions. This issue becomes a great concern to facilities such as a Nuclear Power Plants (NPP), with specialized equipment and machinery that is not only expensive, but critical to safe operation. As such, there is considerable interest worldwide in vertical and three-dimensional (3D) isolation systems. This paper examines several vertical and 3D isolation systems that have been proposed and their potential application to modern nuclear facilities. In particular, a series of case study analyses of a modern NPP model are performed to examine the benefits and challenges associated with 3D isolation compared with horizontal isolation. It was found that compared with the general horizontal isolators, isolators that have vertical frequencies of no more than 3 Hz can effectively reduce the vertical in-structure responses for the studied NPP model. Among the studied cases, the case that has a vertical isolation frequency of 3 Hz is the one that can keep the horizontal period of the isolators as the first period while having the most flexible vertical isolator properties. When the vertical frequency of isolators reduces to 1 Hz, the rocking effect is obvious and rocking restraining devices are necessary.

• International Journal of Knowledge Content Development & Technology
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• 제13권2호
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• pp.7-22
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• 2023

The development of rural areas is expected to be holistic covering all essential infrastructure. Community information centres (CICs) are agen- cies that should be part of the infrastructures for rural development. Unfortunately, these centres are hardly seen in rural communities in Nigeria, including Afikpo in Ebonyi State. Thus, this study was conceived to explore the perceptions of citizens towards the establishment of CICs in the locality. It adopted survey research method with questionnaire as instrument for data collection, which was self-developed and validated by experts with a pre-texted reliability index of 0.72. A total of 399 copies of the questionnaire were distributed, out of which 267 copies were properly completed, representing 67% and were used for analysis. Findings revealed that the citizens have overall positive perception to- wards establishing the CICs; they are also knowledgeable of the benefits of such centres. Furthermore, there are workable suggestions on ways of establishing, funding and managing CICs in Afikpo. In addition, about 65% of the respondents indicated interest to assist and support the funding and management of the CICs when established. However, the challenges of inadequate funding and support as well as the possible politics of where to site/locate the CICs in Afikpo, are likely impediments to the project. The study concluded that citizens have strong and positive disposition towards establishing CICs in Afikpo. The implications of such CICs for technological innovations were analysed. The study recom- mends, among others, that government should see the establishment of CICs as priority projects that would significantly contribute to the growth and development of rural communities in Nigeria; communities in Afikpo should explore self-help approach to development; and political representatives from Afikpo should take advantage of establishing CICs as constituency projects for the citizens.

• 의학교육논단
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• 제17권3호
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• pp.110-121
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• 2015

Competency-based medical education (CBME) is an outcome-oriented curriculum model for medical education that organizes learning activities and assessment methods according to defined competencies as the learning outcomes of a given curriculum. CBME emerged to address the accountability of medical education in response to growing concerns about the patient safety in North America in the 1970s, and the number of medical schools adopting CBME has dramatically increased since 1990. In Korea, CBME has been under consideration as an alternative curriculum model to reform medical education since 2006. The purpose of this paper is three-fold: (1) to review the literature on CBME to identify the challenges and benefits reported in North America, (2) to summarize the process and experiences of planning and implementing CBME at Inje University College of Medicine, and finally (3) to provide recommendations for Korean medical schools to be better prepared for the successful adoption of CBME. In conclusion, one of the key factors for successful CBME implementation in Korea is how well an individual school can modify the current curriculum and rearrange the existing resources in a way that will enhance students' competencies while maximizing the strengths of the school's existing curriculum.

• Journal of Forest and Environmental Science
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• 제29권4호
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• pp.249-256
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• 2013

The aim of the study was to reveal the scope and benefits derives from establishing carbon forests in a country like Bangladesh. Carbon forestry is the modernized forestry practice that evolves no cutting of trees or vegetation rather conserves them in the wood. Trees might be the source of carbon sink at large scale by establishing carbon forests. To find out how and in what extent forests of Bangladesh could contribute to global emission reduction, tree species of economic importance were taken into account about their carbon sequestration potential. Data source was a secondary one. Bangladesh has subtropical evergreen and deciduous forest tree species. Here trees can sequester almost 45-55 percent organic carbon in their biomass. On an average, trees in different types of stands can sequester 150-300 tC/ha. Carbon value of these forests might be 7,500-15,000 USD per hactre (assuming 50 USD per equivalent $tCO_2$). Thus, accounting tree carbon credits of total forested lands of Bangladesh, there might be a lump sum value of $1.89{\times}10^{10}-3.79{\times}10^{10}$ USD. If soil carbon is added, this amount would jump. Alternatively, there are two times higher spaces as marginal lands than this for starting carbon forestry. However, carbon forestry concept is still a theoretical conception unless otherwise their challenges are addressed and solved. Despite of this, forests of Bangladesh might be the key showcase for conserving biodiversity in association with carbon capture. Protected areas in Bangladesh are of government wealth, however, degraded and denuded waste and marginal lands might be the best fit for establishing carbon forests.

• 한국건축시공학회지
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• 제23권6호
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• pp.809-820
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• 2023

현대 사회에서는 1인 가구가 증가하고 주거 공간에 대한 수요가 증가하고 있으며 이에 대한 적절한 대안 모색이 중요하다. 빠른 시간 내에 경제적이고 지속 가능한 주거 공간을 제공하기 위한 방법으로 모듈러 건축이 주목받고 있다. 본 연구에서는 BIM(Building Information Modeling) 기술을 활용한 모듈러 건축 유닛 설계 및 시공 과정 최적화 방법을 제안한다. 1인 가구의 주거 요구사항과 삶의 질 향상을 위한 요인을 분석하였다. 이를 바탕으로 BIM을 활용하여 효율적이고 경제적인 모듈러 공동주택 유닛을 개발하였다. BIM은 건축 요소의 시각화 및 상호 연결을 제공하여 설계 과정의 오류를 최소화하고 생산성을 향상시킬 수 있다. 모듈러 건축의 장점과 한계를 평가하였다. BIM을 활용한 모듈러 건축물은 주거 문제를 해결할 수 있는 효과적인 대안으로 제시될 수 있으며 주거 공간의 품질과 다양성을 높일 수 있다. 다만 기술적 요구사항 및 비용 등의 한계도 고려되어야 한다. BIM 기반 1인 가구 공동주택 유닛 설계의 가능성과 장점을 제시하고 1인 가구 개선을 위한 실질적인 해결책으로 활용될 수 있다.

• 전기학회논문지
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• 제60권3호
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• pp.566-571
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• 2011

As Plug-in Hybrid Vehicle and Electric Vehicle (PHEV/EV) take a greater share in the personal automobile market, their high penetration levels may bring potential challenges to electric utility especially at the distribution level. Thus, there is a need for the flexible charging management strategy to compromise the benefits of both PHEV/EV owners and power grid side. There are many different management methods that depend on the objective function and the constraints caused by the system. In this paper, the schema and dispatching schedule of centralized PHEV/EV charging spot network are analyzed. Also, we proposed and compared three power allocation strategies for centralized charging spot. The first strategy aims to maximize state of vehicles at plug-out time, the rest methods are equalized allocation and prioritized allocation based on vehicles SoC. The simulation results show that each run of the optimized algorithms can produce the satisfactory solutions to response properly the requirement from PHEV/EV customers.

• 자원ㆍ환경경제연구
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• 제11권2호
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• pp.211-231
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• 2002

This paper summarizes the results of a study that assess how a demand side management (DSM) system addresses key economic and environmental challenges facing in the Korean natural gas sector considering; ${\bullet}$ high discrepancies of seasonal consumption volume and of load factor in unmatured domestic LNG market, ${\bullet}$ unfavorable and volatile international LNG market, imposing with the contestable "take-or-pay" contract terms, ${\bullet}$ low profile of LNG and existence of market barriers against an optimal fuel mix status in the industrial energy sector. A particular focus of this study is to establish an 'extended' DSM system in the unmatured gas market, especially in industry sector, that could play a key role to assure an optimum fuel mix scheme. Under the concept of 'extended' DSM, a system dynamics modeling approach has been introduced to explore the option to maximize economic benefits in terms of the national energy system optimization, entailing different ways of commitments accounting for different DSM measures and time delay scenarios. The study concludes that policy options exist that can reduce inefficiencies in gas industry and end-use system at no net costs to national economy. The most scenarios find that, by the year 2015, it is possible to develop a substantial potential of increased industrial gas end-uses under more reliable and stable load patterns. Assessment of sensitivity analysis suggests that time delay factor, in formulating DSM scenarios, plays a key role to overcome various market barriers in domestic LNG market and provides a strong justification for the policy portfolios 'just in time' (time accurateness), which eventually contribute to establish an optimum fuel mix strategy. The study indicates also the needs of advanced studies based on SD approach to articulate uncertainty in unmatured energy market analysis, including gas.