In this paper, numerical simulations were conducted to secure both flow distribution and uniform flow discharge through a wall mount type air sterilizer. In order to increase the reliability of the simulation results where there is no well-known validation case for air sterilizer, mesh sensitivity study was performed under the constraint that y+ set to one for k-w SST turbulent modeling for both the air sterilizer and the fan. The installation of various guides and structures was reviewed in the point of flow distribution and pressure drop inside the sterilizer, and the exhaust pressure conditions were predicted to secure uniform flow discharge at outlets. This study has been done based on the computational analysis during the development stage of the air sterilizer, and the results will be verified through physical testing after production of prototype.

Non-conforming mesh를 이용해 구조적인 불연속성을 해석 시 요소 내 함수 불연속성과 특이점이 존재하며, 이로 인해 계산의 효율 성이 저하된다. 본 연구에서는 이 문제를 해결하기 위해 모멘트 피팅법을 응용한 선택적 확장기법(Duster and Allix, 2020)을 토대로 새로운 고효율 확장 기법을 제시하였다. 특히, 적분과정에서의 비효율성에 초점을 두고 두가지 개선 방안을 제안하고 이를 수치 예제 를 통해 검증하였다. 첫째로 음함수-모멘트간 효율적 계산을 위해 인공신경망을 도입하였으며, 기존 확장 기법에 비해 해의 정확성이 유지되면서도 효율적인 계산이 가능함을 확인하였다. 더불어, 구조 해석과 형상 표상용 격자를 분리, 낮은 밀도의 구조 해석 격자에서 도 정확성이 향상되었음을 보였다.

Traditional building technique has been used as the main technology in the field of architectural heritage conservation in South Korea. It has remained this way with very little resistance until now. But the time has come to question the appropriateness of traditional technique as conservation technique. In this paper a study was done on the properties of the traditional technique and the architectural heritage conservation technique in order to define the appropriateness between the two techniques. As a result the traditional technique was found to be unfit for conservation technique. The reasons are as follows. First, there is a time gap between the traditional technique and the time when the heritage was first built. Second, conservation work is about retaining the values of being a heritage while the traditional technique is about safeness and practicality. Third, the use of traditional technique comes with using the tools of its time which cannot ensure the safety of the heritage. The traditional technique must be looked upon as one of an option in the field of conservation. We must develop a better conservation technology by finding balance between the traditional technique and modern science. And further more an aggressive investment must be made in order to realize this objective.

Recently, it is being carried out the project to evaluate the properties of materials harvested from nuclear reactor after the decommissioning of Kori Unit 1. However, it is not sufficient adequate machining equipment and remote machining technique to perform the projects for evaluation of materials harvested from nuclear reactor. Thus, it is required to develop the remote machining technique in hotcell to evaluate the mechanical properties of nuclear reactor materials. The machining technique should be performed inside a hotcell to evaluate mechanical properties of materials harvested from nuclear reactor and is essential to prevent radiation exposure of workers. Also, it is essential to design the apparatus and develop the machining process so that it can be operated with a manipulator and minimize contamination in hotcell. In this research, development of remote specimen machining technique in hotcell such as machining apparatus, technique and process for compact tension specimens of material harvested from nuclear reactor are described. Remote machining technique will be useful in specimen machining to evaluate changes in mechanical properties of materials harvested in high-radioactive reactor. Also, it is expected that various types of specimens can be machining by applying the developed machining technique in the future.

The hydro-mechanical behavior of rock mass in natural barriers is a critical factor of interest, and it is mainly determined by the characteristics of the fractures distributed in the rock mass. In particular, the aperture and contact area of the fractures are important parameters directly related to the fluid flow and significantly influence the hydro-mechanical behavior of natural barriers. Therefore, it is necessary to analyze the aperture and contact area of fractures distributed in potential disposal sites to examine the long-term evolution of the natural barriers. This study aims to propose a new technique for analyzing the aperture and contact area using the natural fractures in KURT (KAERI Underground Research Tunnel), an underground research facility for the deep geological disposal of high-level radioactive waste. The proposed technique consists of a matching algorithm for the three-dimensional point cloud of the upper and lower fracture surfaces and a normal deformation algorithm that considers the fracture normal stiffness. In the matching process of upper and lower fracture surfaces, digital images obtained from compression tests with pressure films are used as input data. First, for the primary matching of the upper and lower fracture surfaces, an iterative closest point (ICP) algorithm is applied in which rotation and translation are performed to minimize the distance error. Second, an algorithm for rotation about the x, y, and z axes and translation in the normal direction is applied so that the contact area of the point cloud is as consistent as possible with the pressure film image. Finally, by applying the normal deformation algorithm considering the fracture normal stiffness, the aperture and contact area of the fracture according to the applied normal stress are derived. The applicability of the proposed technique was validated using 12 natural fractures sampled from KURT, and it was confirmed that the initial apertures were derived similarly to the empirical equation proposed in the previous study. Therefore, it was judged that the distribution of apertures and contact areas according to applied normal stress for laboratory-scale fractures could be derived through the technique proposed in this study.

A tensile test is performed to obtain the mechanical property data of the spent fuel cladding. In general, the elastic modulus, elongation, yield stress, tensile stress, etc. are obtained by axial tensile test of cladding attaching an extensometer. However, due to the limitation in the number of specimens for spent nuclear fuel that can be made, the ring tensile test (RTT) whose required length of the specimen is short is mainly performed. In the case of RTT, an extensometer or strain gauge cannot be attached because the gauge part of the specimen is formed around the cladding and is short. In addition, since a load is applied in the radial direction of the cladding, a curved portion of the circular cladding is spread out and becomes straight, and then the cladding is tensioned. For this reason, it is difficult to obtain the stress-strain curve directly from the RTT results. Isight, which is used to identify the optimization design parameters, was used to build an optimization process that minimizes the difference between the RTT and the analysis to estimate the material property. For this, the elastic modulus, plastic strain, and the radius of the RTT jig were taken as fixed variables. As variables, isotropic hardening data and plastic stress were taken. The objective function was taken as the minimization of the area difference of the load-displacement curve obtained from the tests and analysis, of the difference in the magnitude of the maximum reaction force, and of the difference in the location where the maximum reaction force occurred. Optimization workflow was configured in the following order. First, using the calculator component, plastic stress design variables were created. Next, ABAQUS was placed to perform analysis using design variables, and the reaction force or displacement was calculated. After that, the reaction force was calculated considering the 1/4 symmetry condition using the script component. After that, the data matching component performed quantitative comparison of test and analysis data. Finally, by utilizing the exploration component, the plastic stress design variable that minimizes the difference in the objective function was obtained by automatically changing six optimization algorithms. In this paper, the constructed optimization process and the obtained plastic stress by applying it to the SUS316 RTT results are briefly described. The established optimization process can be utilized to obtain mechanical property from the results of the cladding RTT of spent nuclear fuel or new material.

Background: The muscles associated with tension-type headache (TTH) are connected to the scalp fascia, which is firmly attached to the superciliary ridge of the frontal bone. However, there is a paucity of data on treatments for TTH that directly target the scalp fasciae. Objectives: We aimed to validate a new manual therapy to treat TTH by applying myofascial relaxation techniques to the scalp and to examine the changes in quality of life and headache characteristics after treatment. Design: pretest-posttest control group design study. Methods: Total 24 participants with TTH (10 males, 14 females) participated in the study. Manual therapy group (MT) received standard manual therapy and scalp myofascial release technique group (SMT) received scalp myofascial release technique twice per week for 4 weeks. Brief Pain Inventory (BPI) and Headache Impact Test (HIT) for quality of life, headache frequency, duration, and Visual Analog Scale (VAS) for intensity were assessed at the pre- and post-treatment. Results: There was a significant improvement within groups in headache frequency (MT P<.05, SMT P<.001), duration (MT P<.05, SMT P<.01), VAS (MT P<.01, SMT P<.001), HIT (MT P<.001, SMT P<.001), and BPI (MT P<.001, SMT P<.001) between the pre- and post-treatment. Group differences were significant for headache duration (P=.027), but the others were not. MT and SMT reduced the impact of headaches on daily life. Also Headache frequency, duration, intensity, and BPI were improved. Conclusion: MT and SMT reduced the impact of headaches on daily life. Also Headache frequency, duration, intensity, and BPI were improved. It has been suggested that both MT and SMT can be used as a non-invasive treatment to treat the TTH, and to improve the quality of life.

The buffer is a critical barrier component in an engineered barrier system, and its purpose is to prevent potential radionuclides from leaking out from a damaged canister by filling the void in the repository. No experimental parameters exist that can describe the buffer expansion phenomenon when Kyeongju bentonite, which is a buffer candidate material available in Korea, is exposed to groundwater. As conventional experiments to determine these parameters are time consuming and complicated, simple swelling pressure tests, numerical modeling, and machine learning are used in this study to obtain the parameters required to establish a numerical model that can simulate swelling. Swelling tests conducted using Kyeongju bentonite are emulated using the COMSOL Multiphysics numerical analysis tool. Relationships between the swelling phenomenon and mechanical parameters are determined via an artificial neural network. Subsequently, by inputting the swelling tests results into the network, the values for the mechanical parameters of Kyeongju bentonite are obtained. Sensitivity analysis is performed to identify the influential parameters. Results of the numerical analysis based on the identified mechanical parameters are consistent with the experimental values.

병렬영상기법인 SENSE 기법은 슬관절 자기공명영상의 검사 시간을 획기적으로 단축할 수 있다. 그러나 기법 적용 시 SENSE factor를 증가시키면 영상에 인공물의 발생이 증가하는 문제점이 있어 개선을 위해 본 연구에서는 최소의 시간이 소요되면서 인공물이 발생하지 않는 최적의 SENSE factor를 제시하고자 하였다. 연구 방법은 SENSE factor 1.0을 기준 으로 0.5 간격씩 5.0까지 변화시켜 팬텀 실험과 임상실험을 시행하였다. 3.0T 초전도 자기공명영상장치와 dS Knee 코일 을 사용하여 T1, T2 강조영상을 획득하였으며, 영상의 비교평가는 임상 경력 10년 이상의 방사선사 10명이 5점 척도로 평가한 후, 일원배치 분산분석과 사후분석을 통해 유의한 차이가 있는지 판단하였다. 연구 결과 팬텀 실험은 T1, T2 강조 영상 모두 SENSE factor를 1.5 이하로 하였을 때 기준 영상과 차이가 없었으며, 임상실험은 SENSE factor를 2.0 이하로 하였을 때 기준 영상과 차이가 없었다. 결론적으로 슬관절 자기공명영상 시 검사 시간을 단축하면서 인공물이 발생하지 않는 최적의 SENSE factor는 팬텀 실험의 경우 1.5, 임상실험의 경우 2.0이 적정하리라 사료된다.

컴퓨터 성능의 발전으로 빅데이터의 효율적인 사용이 가능해지면서, 심층 학습(deep learning)은 다양한 의료 분야에 활용할 수 있는 핵심적인 인공지능(artificial intelligence, AI) 기법으로 각광받고 있다. 이에 본 종설은 뇌종양 진단과 치료에 사용되는 자기공명영상(magnetic resonance imaging, MRI)의 심층 학습 기법을 소개하고자 하였다. 먼저 국내 AI의 의료 분야 도입의 동향을 분석하고, 이를 바탕으로 MRI를 활용한 뇌종양의 진단과 치료에 적용할 수 있는 심층 학습 기법과 그 결과들을 기술하였다. 뇌종양 진단과 치료 시, 심층 학습을 이용한 최근 사례는 영상 분류, 영상 품질 개선, 영상 분할로 나타났으며, 질병의 진단과 치료에 적용할 수 있는 객관적이고 높은 성능 수치를 나타내면서 그 유용성을 확인 할 수 있었다. 종합하자면, 심층 학습은 질병의 진단과 치료에 적용할 수 있는 유용한 지표이며, AI 역량을 지닌 의료진의 지도하에 점진적인 도입이 이뤄진다면 질병의 진단과 치료에 큰 도움을 주는 훌륭한 소프트웨어로 활용될 것으로 여겨진다. 본 종설이 심층 학습을 이해할 때 많은 도움이 되길 바라며, 향후 관련 연구를 수행할 때 가이드라인으로 활용될 것을 기대 한다.

이 연구의 목적은 커피점문점의 공간적 경쟁구도 및 입지우위를 미시적인 공간 해상도에서 탐색하 는 것이다. 분석지역은 인천광역시이며, 분석연도는 2018년이다. 분석방법으로는 공간 빅데이터 기반 의 i2SFCA(Inverted Two-Step Floating Catchment Area)와 Contour Tree 기법을 활용하였다. 분 석결과, 개별 커피전문점의 입지 효율성은 큰 편차를 드러냈으며, 연수3동, 선학동, 도원동 등의 순으 로 우수하였다. 또한, 공시지가가 높은 곳에 입지한 커피전문점 간의 출혈경쟁을 확인할 수 있었다. 마지막으로 역세권이 아닌 지역에서도 커피전문점의 입지 효율성이 높은 지역, 이른바 틈새 지역 (niche region)을 확인할 수 있었다. 커피전문점의 소비행태에 관한 빅데이터의 활용 제약은 본 연구 의 한계와 직결되므로, 소비행태 빅데이터 기반으로 커피전문점의 입지 문제 정교하게 다루는 후속연 구가 필요하다.

동아시아의 ‘본류’에서 글로벌 차원으로 ‘지류’가 확장된 한류(Korean Wave)는 시기별, 권역별, 그리고 내용에 따라 발전 단계를 구분할 수 있 다. 한류의 발전 단계를 모두 4기(신한류 포함)로 구분한 유형 분류 틀에 따르면 본 연구의 대상 지역인 중남미권을 위시로 하는 非아시아권은 모 두 2000년대 후반 이후인 한류 2기에 속한다. 특히, 2020년 이후를 신 한류(K-culture)로 지칭되며 이 4기의 특징은 한류의 1기의 대표 콘텐츠 인 K-drama를 필두로, K-pop, K-movie, K-food, K-game 등 ‘K(S)’ 마크를 장착한 다양한 콘텐츠를 가지고 있는 토탈 브랜드(Total Brand) 형태로 진화했다. 기존의 연구물을 바탕으로 본고는 기존의 한류관련 연 구에 방법론적 차별화를 통해 對 중남미 한류 현상의 고찰을 목적으로 한다. 특히 본고는 중남미지역의 한류는 기존의 한류 발전 단계에 부합 하는가? 에 대한 연구 질문을 던지며, R 프로그램을 활용하여 워드 클라 우드(Word Cloud) 기법을 이용한 K-콘텐츠 관련 빅데이터 분석을 한 다. 텍스트 마이닝을 통한 빈도분석에 따르면 중남미 한류 태동기인 2010년 K-pop이 주요 ‘동력’이었으며 10년이 지난 현재도 K-pop의 비 중이 여전히 높다는 결과가 도출되었다. 따라서, 중남미지역은 한류 태동 기의 양상에서 크게 성장 및 확대되었다고 보기에는 다소 미흡하다. 즉 중남미지역의 한류는 K-contents의 다양화이기 보다는 K-pop과 관련된 음악 장르의 확산과 고착화의 양상으로 볼 수 있다.

The effect of motion taping on the grasping power of the wrist is investigated and here Based on the data obtained from the This study was conducted to provide a theoretical background for the study. Motion taping was performed on the wrist for middle-aged people between 50s and 60s, and the change in wrist gripping power through an electronic dynamometer was tested. According to the wrist grip test results, it was investigated that the application of motion taping has a great effect on the gripping power of the wrist. It is hoped that motion taping will be a tool to reduce musculoskeletal industrial accidents, and it will be helpful to improve the quality of life of workers by reducing the labor intensity or softening the wrist through motion taping.

In preparation of porous carbon materials microwave oven brightening is one of the warming modes used ever. The various procedures that take place in microwave combustion process include carbonization, incitation, and recovery and thus carbon is defined. This paper compares ideal conditions of traditional warming methods, as well as their implementation potential, losses, and specifications. This porous carbon with heat treatment possesses various properties and they are well suited for energy applications which require constrained space such as hydrogen storage in solid-state and supercapacitors. The enhanced properties are chemical and thermal stability, ready availability, low framework density and ease of processability. The recent trend in class of porous carbons is Activated Carbons that are employed traditionally as adsorbents or catalyst supporters but currently, they found potent applications in fabricating for hydrogen storage materials and supercapacitors. These activated carbons are much enhanced form in class of porous carbon materials and they possess the capability to enable hydrogen economy, where the energy carrier is hydrogen. Therefore, the utility of activated carbons as a source for energy storage experiences a rapid growth at current trend and they possess significant advances. This investigation is based on detailed cost development data and electrical imperativeness applications.