• 한국광학회지
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• 제9권1호
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• pp.25-30
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• 1998

본 논문에서는 다중모드 광섬유에서 발생하는 모드스페클 패턴을 이용한 M개의 입력단과 N개의 출력단 사이의 간단한 광연결 방법에 관하여 기술하였다. 적절히 여기된 모드스페클 패턴을 목적지 코드로 사용하고, M개의 홀로그램을 중첩기록한 Vander Lugt 정합필터를 사용하여 수신되는 모드스페클 패턴을 분리 검출함으로써 nonblocking 완전광연결이 가능함을 설명하였다. 광섬유에 입사되는 빔입사각을 바꾸어주거나, 입력광의 편광방향을 바꾸어주면서 출력단에 발생되는 모드 스페클 패턴들의 직교특성을 조사하였다. 임의의 M * N 광연결이 가능함을 보이기 위한 기초 실험으로 코어직경이 50.mu.m인 경사형 굴절율 분포의 4 * 4 다중모드 광섬유 결합기를 사용하여 1 * 2 광연결과 2 * 1 광연결 실험을 수행하였다.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.776-792
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• 2021

Conventional integral effect test facilities were constructed to enable the precise observation of thermal-hydraulic phenomena and reactor behaviors under postulated accident conditions to prove reactor safety. Although these facilities improved the understanding of thermal-hydraulic phenomena and reactor safety, applications of new technologies and their performance tests have been limited owing to the cost and large scale of the facilities. Various nuclear technologies converging 4th industrial revolution technologies such as artificial intelligence, drone, and 3D printing, are being developed to improve plant management strategies. Additionally, new conceptual passive safety systems are being developed to enhance reactor safety. A new integral effect test facility having a noticeable scaling ratio, i.e., the (UNIST reactor innovation loop (URI-LO), is designed and constructed to improve the technical quality of these technologies by performance and feasibility tests. In particular, the URI-LO, which is constructed using a transparent material, enables better visualization and provides physical insights on multidimensional phenomena inside the reactor system. The facility design based on three-level approach is qualitatively validated with preliminary analyses, and its functionality as a test facility is confirmed through a series of experiments. The design feature, design validation, functionality test, and future utilization of the URI-LO are introduced.

• Current Optics and Photonics
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• 제3권1호
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• pp.54-65
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• 2019

To develop a biomarker predicting tumor treatment efficacy is helpful to reduce time, medical expenditure, and efforts in oncology therapy. In clinics, microvessel density using immunohistochemistry has been proposed as an indicator that correlates with both tumor size and metastasis of cancer. In the preclinical study, we hypothesized that vascular morphometrics using optical coherence tomography angiography (OCTA) could be potential indicators to estimate the treatment efficacy of breast cancer. To verify this hypothesis, a 13762-MAT-B-III rat breast tumor was grown in a dorsal skinfold window chamber which was applied to a nude mouse, and the change in vascular morphology was longitudinally monitored during tumor growth and metronomic cyclophosphamide treatment. Based on the daily OCTA maximum intensity projection map, multiple vessel parameters (vessel skeleton density, vessel diameter index, fractal dimension, and lacunarity) were compared with the tumor size in no tumor, treated tumor, and untreated tumor cases. Although each case has only one animal, we found that the vessel skeleton density (VSD), vessel diameter index and fractal dimension (FD) tended to be positively correlated with tumor size while lacunarity showed a partially negative correlation. Moreover, we observed that the changes in the VSD and FD are prior to the morphological change of the tumor. This feasibility study would be helpful in evaluating the tumor vascular response to treatment in preclinical settings.

• 수산경영론집
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• 제50권3호
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• pp.73-86
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• 2019

The purpose of this study is to provide logical and policy justification for the feasibility and sustainability of the project through analysis of economic ripple effects of the fishing village new deal 300 project. To do this, we applied the industry-related analysis, which is mainly used to analyze the economic ripple effects, to the fishing village new deal 300 project. The industry association analysis classifies the detailed project of the preliminary plan for the selection of the business into the software business such as the hardware business and the capacity enhancement in the construction field and analyzes the economic ripple effect through the inter-industry association. As a result, it is expected that the fishing village new deal 300 project will have a positive economic impact. When the total investment of 3 trillion won is invested in the project, it is estimated that the production inducement effect and the value added effect are 5,545.3 billion won and 2,102.7 billion won, respectively. In addition, 62,005 get job inducements, where 10,952 employment inducements were associated with job creation. The analysis of the above impacts seems to have secured the logical justification for the implementation of the fishing village new deal 300 project.

• Earthquakes and Structures
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• 제16권6호
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• pp.743-755
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• 2019

In this paper, a new system of seismic isolation for buildings - called suspended columns - is introduced. In this method, the building columns are placed on the hinged cradle seats instead of direct connection to the foundation. In this system, each of the columns is put on a seat hung from its surrounding area by a number of cables, for which cavities are created inside the foundation around the columns. Inside these cavities, the tensile cables are hung. Because of the flexibility of the cables, the suspended seats vibrate during an earthquake and as a result, there is less acceleration in the structure than the foundation. A Matlab code was written to analyze and investigate the response of the system against the earthquake excitations. The findings showed that if this system is used in a building, it results in a significant reduction in the acceleration applied to the structure. A shear key system was used to control the structure for service and lateral weak loads. Moreover, the effect of vertical acceleration on the seismic behavior of the system was also investigated. Effect of the earthquake characteristic period on the system performance was studied and the optimum length of the suspension cables for a variety of the period ranges was suggested. In addition, measures have been taken for long-term functioning of the system and some practical feasibility features were also discussed. Finally, the advantages and limitations of the system were discussed and compared with the other common methods of seismic isolation.

• Journal of the Korean Wood Science and Technology
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• 제47권1호
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• pp.51-65
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• 2019

A wood-plastic composite (WPC) paver block was manufactured using wood chips waste through an extrusion process, and it was intended to be used for paving in basic rest areas. The first stage in this study covered preliminary tests in terms of flexural strength and dimensional swelling to determine the optimal WPC compounding mix condition, by variation of the WPC ingredients. Next, three different paver blocks including the WPC block, a non-porous cement block, and a porous cement block were tested in terms of various material properties in the laboratory. Finally, two outdoor test sections of the proposed paver blocks were prepared to simulate a basic rest area. Test results indicated that the flexural strength of the WPC paver blocks was about 1.6 times greater than that of the tested cement paver blocks. The WPC block pavement was unaffected by water buoyance as well as volume expansion due to swelling. Results from the impact absorbance test and light falling weight deflectometer (LFWD) test clearly showed that the WPC block paving system marginally satisfied the comfortable and safe hardness range from the pedestrians' perspective, while the results demonstrated that it is structurally sound for application as a road paving block.

• 대한건축학회논문집:계획계
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• 제34권6호
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• pp.47-56
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• 2018

This study aims to reconsider public architecture as effective resources for the local regeneration and draws a couple of issues based on analysis of planning status and cases from the perspectives of local regeneration. Through the analysis, this study suggests following as ways of improvement of public architecture planning: first, in order to secure systematic management of local regeneration, it is necessary to build up a dedicated organization or collaboration system that organically links and manages public facilities. Also related criteria that include the feasibility study, preliminary examination system, conduct review of investment and review standards need to be supplemented. Second, it is necessary to establish an integrated plan including the periphery of public architecture in the aspect of integrated urban planning, and to set up a selection of location standard that supports public architecture be a local center. Lastly, to activate local communities, the study proposes diversification of ways of combining programs and a process for participation and operating funds.

• 한국정보통신학회논문지
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• 제25권3호
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• pp.486-489
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• 2021

Recently, the demand for the use of personal mobility vehicles, such as an electric kickboard, is increasing explosively because of its high portability and usability. However, the number of traffic accidents caused by personal mobility vehicles has also increased rapidly in recent years. To address the issues regarding the driver's safety, we propose a novel approach that can monitor context information around personal mobility vehicles using deep learning-based object detection and smartphone captured videos. In the proposed framework, a smartphone is attached to a personal mobility device and a front or rear view is recorded to detect an approaching object that may affect the driver's safety. Through the detection results using YOLOv5 model, we report the preliminary results and validated the feasibility of the proposed approach.

• 청정기술
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• 제28권1호
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• pp.32-37
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• 2022

Food waste is produced from food factories, food services, and home kitchens. The generated mass reached 5.4 million tons/year in 2020. The basic management technology for such waste has been biological degradation under an anaerobic environment. However, the whole process is intrinsically slow and considerably affected by the inner physicochemical properties of the waste and other surrounding conditions, which makes optimization of the process difficult. The most promising options to counter this massive generation of waste are eco-friendly treatments or recycling. As a preliminary step for these options, attempts were made to evaluate the feasibility and usability of three simulative models based on reaction kinetics. Model (A) predicted relative changes over reaction time for reactant, intermediate, and product. Overall, an increased reaction rate produced less intermediate and more product, thereby leading to a shorter total reaction time. Particle diminishing model (B) predicted reduction of the total waste mass. The smaller particles diminished faster along with the dominant effect of microbial reaction. In Model (C), long-chain cellulose was predicted to transform into reducing sugar. At a standard condition, 48% of cellulose molecules having 10⁵ repeating units turned into reducing sugar after 100 h. Also it was found that the optimal enzyme concentration where the highest amount of remnant sugar was harvested was 1 mg L^-1.

• Journal of Information Science Theory and Practice
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• 제11권1호
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• pp.61-78
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• 2023

Ontological knowledge modelling of epic texts, though being an established research arena backed by concrete multilingual and multicultural works, still suffers from two key shortcomings. Firstly, all epic ontological models developed till date have been designed following ad-hoc methodologies, most often combining existing general purpose ontology development methodologies. Secondly, none of the ad-hoc methodologies consider the potential reuse of existing epic ontological models for enrichment, if available. This paper presents, as a unified solution to the above shortcomings, the design and development of GOMME - the first dedicated methodology for iterative ontological modelling of epics, potentially extensible to works in different research arenas of digital humanities in general. GOMME is grounded in transdisciplinary foundations of canonical norms for epics, knowledge modelling best practices, application satisfiability norms, and cognitive generative questions. It is also the first methodology (in epic modelling but also in general) to be flexible enough to integrate, in practice, the options of knowledge modelling via reuse or from scratch. The feasibility of GOMME is validated via a first brief implementation of ontological modelling of the Indian epic Mahabharata by reusing an existing ontology. The preliminary results are promising, with the GOMME-produced model being both ontologically thorough and competent performance-wise.