In the case of dry storage facilities, slipping of the cask or tip-over are dangerous phenomena. For this reason, in dry storage facilities, measures against slipping and tip-over or related safety evaluations are important. Accidental conditions that can cause cask slippage and tip-over in dry storage facilities include natural phenomena such as floods, tornadoes, tsunamis, typhoons, earthquakes, and artificial phenomena such as airplane crashes. However, among natural phenomena, earthquakes are the most important natural phenomenon that causes tip-over. Also, many people had the stereotype that Korea is an earthquake-safe zone before 2016. However, earthquakes become a major disaster in Korea due to the 2016 Gyeongju earthquake and the 2017 Pohang earthquake, followed by the Goesan earthquake in October 2022. In this paper, seismic analysis was performed based on dry storage facilities including multiple casks. Design variables for the construction of an analysis model for dry storage facilities were investigated, and seismic analysis was performed. To evaluate tip-over accident during earthquake, seismic load was used from 0.2 g PGA to 0.8 g PGA and these earthquakes were followed Design Response Spectrum (DRS) in RG 1.60. The friction coefficient of concrete pad was used from 0.2 to 1.0. As a result of the analysis, tip-over accident could not find in the analysis from 0.2 g to 0.6 g. However, tip-over was appeared at friction coefficients of 0.8 and 1.0 at 0.8 g PGA. Tip-over angular velocity of cask was derived by seismic analysis and was compared with formula and tip-over analysis results. As a result, a generalized dry storage facility analysis model was proposed, and dry storage facility safety evaluation was conducted through seismic analysis. Also, tip-over angular velocity was derived using seismic analysis for tip-over analysis.

This study proposes an RCS composite damping device that can achieve seismic reinforcement of existing buildings by dissipating energy by inelastic deformation. A series of experiments assessing the performances of the rubber core pad, hysteretic steel slit damping device, and hybrid RCS damping device were conducted. The results showed that the ratios of the deviations to the mean values satisfied the domestic damping-device conformity condition for the load at maximum device displacement in each direction, at the maximum force and minimum force at zero displacement, as well as the hysteresis curve area. In addition, three analysis models based on load-displacement characteristics were proposed for application to seismic reinforcement design. In addition, the validity of the three proposed models was confirmed, as they simulated the experimental results well. Meanwhile, as the shear deformation of the rubber-core pad increased, the hysteretic behavior of super-elasticity greatly increased the horizontal force of the damping device. Therefore, limiting the allowable displacement during design is deemed to be necessary.

Some Spent Fuel Pools (SFPs) will be full of Spent Nuclear Fuels (SNFs) within several years. Because of this reason, building interim storage facilities or permanent disposal facilities should be considered. These storage facilities are divided into wet storage facilities and dry storage facilities. Wet storage facility is a method of storing SNF in SFP to cool decay heat and shielding radiation, and dry storage facility is a method of storing SNF in a cask and placing on the ground or storage building. However, wet storage facilities have disadvantages in that operating costs are higher than that of dry storage facilities, and additional capacity expansion is difficult. Dry storage facilities have relatively low operating costs and are relatively easy to increase capacity when additional SNFs need to be stored. For this reason, since the 1990s, the number of cases of applying dry storage facilities has been increasing even abroad. Dry storage facilities are divided into indoor storage facilities and outdoor storage facilities, and outdoor storage facilities are mostly used to take advantage of dry storage facilities. In the case of outdoor storage facilities, the cask in which SNFs are stored is placed on a designed concrete pad. During this storage, the boring heat generated by SNFs cools into natural convection and the cask shields the radiation that SNFs generates. However, if an accident such as an earthquake occurs and the cask overturns during storage, there may be a risk of radiation leakage. Such a tip-over accident may be caused by the cask slipping due to the vibration of an earthquake, or by not supporting the cask properly due to a problem in the concrete pad. Therefore, in the case of outdoor dry storage facilities, it is necessary to evaluate the seismic safety of concrete pads. In this paper, various soil conditions were applied in the seismic analysis. Soil conditions were classified according to the shear wave velocity, and the shear wave velocity was classified according to the ground classification criteria according to the general seismic design (KDS 17 10 00). The concrete pad was designed with a size that 8 casks can be arranged at regular intervals, and 11# reinforcing bars were used for the design of the internal reinforcement of the concrete pad according to literature research. The cask was designed as a rigid body to shorten the analysis time. The soil to which the elastic model was applied was designed under the concrete pad, and infinite elements were applied to the sides and bottom of the soil. The effect on the concrete pad and cask by applying a seismic wave conforming to RG 1.60 to the bottom of the soil was analyzed with a finite element model.

The purpose of this study was to develop a 3D mesh-type impact protection pad with excellent motion adaptability and functionality by applying 3D printing technology. The hexagonal 3D mesh, which constitutes the basic structure of the pad, comprises two types: small and large. The bridge connecting the basic units was designed as the I-type, V-type, IV-type, and VV-type. After evaluating the characteristics of the bridge, it was found that the V-type bridge had the highest flexibility and tensile elongation. The hip joint pad and knee pad were completed by combining the hexagonal 3D mesh structure with the optimal bridge design. The impact protection pad was printed using a fused deposition modeling-type 3D printer with a filament made of thermoplastic polyurethane material, and the protection pad’s performance was evaluated. When an impact force of approximately 6,500N was applied to the pad, the force attenuation percentage was 78%, and when an impact force of approximately 8,000N was applied, the force attenuation percentage was 75%. Through these results, it was confirmed that the 3D-printed impact protection pad with a hexagonal 3D mesh structure connected by a V-shaped bridge developed in this study can adapt to changes in the body surface according to movement and provides excellent impact protection performance.

Various kinds of friction materials were manufactured by adding 10%, 20%, and 30% of reduced iron, respectively, which has been obtained during the reduction process of blast furnace sludge extracted from the blast furnace, and its iron oxide, instead of existing barium sulfate(BaSO4) among the components of automobile brake friction materials. Fundamental physical property test and friction performance test, etc., using a brake dynamometer were carried out against these friction materials. Furthermore, when the expensive filling material, BaSO4 was substituted by reduced iron and added to the friction material, the added content of reduced iron for an excellent friction characteristic considering the heat emission temperature, wear, etc., was 10%. In the fundamental physical property test, as the added content of blast furnace sludge or reduced iron increased, and as the content increased, the shear strength and bonding strength of friction materials decreased, but both of them indicated sufficient strengths to be applied to a friction material. Even in the frictional performance test using a brake dynamometer, as the added content of blast furnace sludge or reduced iron increased, the friction coefficient reacted insensibly to brake deceleration, and its stability was improved.

레일장대화는 무도상교량의 소음, 진동, 충격 등의 문제점을 해결할 수 있는 경제적인 방안 중 하나이며, 최근 연동식 침목고정장치 를 이용한 SSF 공법이 개발된 바 있다. 이 연구에서는 연동식 침목고정장치 적용 시 레일 높이 조정 및 열차 통과 시의 충격 흡수를 목 적으로 교량침목 하부에 삽입되는 침목패드의 최적 연직강성을 결정하는 과정을 제시하였다. 침목패드의 최적 연직강성 결정을 위하 여 관련 기존 기준을 검토하였으며, 유연다물체동적해석을 통하여 침목패드의 연직강성 변화에 따른 주행안전성, 승차감 및 궤도의 안전성에 대한 지표들과 교량 응답 변화를 검토하였다. 유연다물체동적해석은 상용프로그램인 ABAQUS와 VI-Rail을 이용하여 수행 하였다. 수치해석은 30m 상로판형교에 대한 교량모델을 이용하여 수행하였으며, 침목패드의 연직강성이 7.5kN/mm ~ 240kN/mm로 변화할 때 ITX 새마을, KTX 및 화차 통과 시의 응답을 산정하였다. 수치해석에 적용된 궤도구성품 조건에서 침목패드의 최적 강성은 100kN/mm로 산정되었다.

본 연구는 스포츠 휴먼브랜드의 굿즈상품(Goods) 가치, 감정반응(PAD), 소비 행동 간 일어나는 현상을 분석하기 위해 2021년 10월 18일~2022년 1월 12일까지 온라인 서베이(URL), DM, E-mail 등을 활용하여 371명을 편의 표준추출법으로 표집하였으며, 불성실한 응답자 51명을 제외한 유효 표본 320명을 인과 관계(SEM)를 적용하여 분석하였다. 첫째, 휴먼 브랜드의 굿즈 가치는 감정반응에 정(+)의 영향으로 가설이 채택되었다. 둘째, 감정반응은 소비 행동에 정(+)의 영향을 미치는 것으로 가설이 채택되었다. 셋 째, 휴먼 브랜드의 굿즈 가치는 소비 행동에 정(+)의 영향을 미치며 부분적으로 가설이 채택되었다. 마지막 으로 굿즈상품(goods) 가치와 소비 행동의 관계에서 감정반응의 간접효과는 통계적으로 유의 의미한 것으 로 나타났다.

본 연구에서는 전기 근육 자극(electrical muscle stimulation, EMS)에 사용되는 기존의 하이드로겔 패드의 단 점인 사용 편의성, 쾌적성 등을 보완할 수 있는 e-textile (electronic textile)을 이용한 전기 근육 자극(electrical muscle stimulation, EMS) 패드인 EMSCT (electrical muscle stimulation conductive textile)를 연구를 하고자 하 였다. SWCNT (Single-Walled Carbon Nanotube)와   의 농도 및 함침 공정 횟수를 변수로 하여, EMSCT는 5 가지 직물(라디론, 네오프렌, 스판쿠션, 폴리100%, 베르가모)에 전도성을 부여하여 실험이 진행되었다. SWCNT (Single-Walled Carbon Nanotube)와   을 이용한 패딩 공정을 거쳤으며, 교류 측정 결과 하이드로겔 과 가장 유사한 교류를 나타내는 것은 SWCNT:   = 2:1의 베르가모 원단이라는 결과를 얻을 수 있었다. 또한, 편 의성, 사용성, 심리적 만족성에 관한 사용성 평가를 통해 기존 하이드로겔 패드에 비해 EMSCT가 좋은 사용성을 가진다는 결과를 얻을 수 있다.

Background: Unstable surface-based core training can significantly enhance core strength, but no studies have compared the effects of balance pad- and sling-assisted exercises. Objects: To study the effects of unstable surface-based balance pad- and sling-assisted core strength exercises on muscle activity. Methods: Twenty male students aged 20–25 years participated in this study. The effects of three types of core strength exercises, performed with a sling or balance pad, on the activities of three muscles, i.e., the right musculus obliquus externus abdominis (EO), right erector spinae (ES), and right gluteus maximus (GM), were examined. Results: 1) In the glute bridge exercise, the percentage of maximum voluntary contraction of the EO, ES, and GM were significantly different between the balance pad- and sling-assisted exercises. The relative contribution of the ES and GM activities to all muscle activity were not significantly different between the two training types, whereas that for EO showed a significant difference. 2) There was no significant difference in the percentage value of maximum voluntary contraction (%MVC) among the EO, ES, and GM during the “leg-lifting with flat support”exercise, and there were no significant difference in the relative contributions between the two training types. 3) In the “side bridge leg separation exercise”, the %MVC of the ES, EO, and GM were significantly different between the two training types. Conclusion: Sling training for core muscles was generally better than balance pad assist training. The majority of physiotherapy patients require core training. Our results could guide physiotherapists in the choice of targeted exercises for these patients.

Background: Mucoepidermoid carcinoma (MEC) is the most common malignant epithelial tumor of the salivary gland in the oral cavity. In South Korea, it occurs most frequently in the palate, retromolar area, floor of the mouth, buccal mucosa, and other areas of the oral cavity. MEC is rare in children and adolescents under 20 years of age, but it is the most common malignant salivary gland tumor in this group. Reconstructive surgery is often required due to cystic lesions or resection of malignancy in the oral cavity. Buccal fat pad (BFP) is a flap that is reliable and suitable for reconstructing oral defects because it has a low complication rate and small volume change over time. Case Presentation: We report the case of a 12-year-old female patient with low-grade MEC on light soft palate with no neck metastasis. After tumor resection the palatal mucosal defect was reconstructed with a BFP flap. Conclusion: The purpose of this article is to discuss the features and treatment methods of MEC that is rarely occurring in children, and the usefulness of BFP for reconstruction. Therefore, we will make a precise diagnosis and treatment as we examine the clinical feature and review the literature.

The friction characteristics of Al-Fe alloy powders are investigated in order to develop an eco-friendly friction material to replace Cu fiber, a constituent of brake-pad friction materials. Irregularly shaped Al-Fe alloy powders, prepared by gas atomization, are more uniformly dispersed than conventional Cu fiber on the brake pad matrix. The wear rate of the friction material using Al-8Fe alloy powder is lower than that of the Cu fiber material. The change in friction coefficient according to the friction lap times is 7.2% for the Cu fiber, but within 3.8% for the Al- Fe alloy material, which also shows excellent judder characteristics. The Al-Fe alloy powders are uniformly distributed in the brake pad matrix and oxide films of Al and Fe are homogeneously formed at the friction interface between the disc and pad, thus exhibiting excellent friction and lubrication characteristics. The brake pad containing Al-Fe powders avoids contamination by Cu dust, which is generated during braking, by replacing the Cu fiber while maintaining the friction and lubrication performance.

목 적 : 공기와 인체조직 간에 경계면에서 자화율 차이로 인한 자장의 불균일은 불균질한 지방소거(fat suppression)을 일으 킨다. 이에 본 연구는 폴리스티렌(polystyrene) 적용 전·후에 따른 자장의 불균일 보정을 통해 fat suppression 개선 효과를 알아보고자 하였다. 대상 및 방법 : Phantom study는 본 연구를 위해 자체 제작한 fat phantom에 테스트물질 공기, 쌀, 폴리스티렌(polystyrene ball bullet), 발포성 폴리스티렌(expandable poly-styrene beads), 폴리프로필렌 칩형태(polypropylene chip type), 폴리프 로필렌 작은 칩형태(polypropylene small chip type)을 각각 넣고, 자화율 차이에 민감한 SPIR T1 weighted image(T1WI) 영상을 획득하여 Fat과 테스트 물질 경계면의 signal intensity(SI)를 측정하였다. Patient study는 2016년 11월부터 동년 12 월까지 neck 검사를 시행한 환자 12명을 대상으로 하였으며, 폴리스티렌(polystyrene ball bullet)을 목에 감쌀 수 있게 자체 제작하여 착용 전·후 SPIR T1WI을 획득하였다. Phantom study의 평가방법은 fat과 테스트 물질 경계면의 SI변화를 알아 보고 SNR을 비교평가 하였고, Patient study는 MRI 전문방사선사 3명이 neck 부분영상의 fat suppression 정도에 대해 리 커트(Likert scale) 5점 척도로 영상을 평가하였다. 통계적 분석은 대응표본 T검정을 이용하여 유의성을 검증하였다. 결 과 : Phantom 영상에서 평균 SI는 공기 1516.5±121.46, 쌀 240.5±4.46, 폴리스티렌 183.83±29.38, 발포성 폴리스티렌 1483.67±155.36, 폴리프로필렌 칩 형태 258.17±3.6, 폴리프로필렌 작은 칩 형태 140±26.07으로 측정되었다. SNR의 경우 는 공기(1495.55) > 발포성 폴리스티렌(1406.32) > 폴리스티렌(660.48) > 쌀(621.98) > 폴리프로필렌 칩 형태(512.91) > 폴리 프로필렌 작은 칩 형태(506.02)의 순으로 확인되었다. Patient study SPIR T1WI 영상의 정성적 평가 결과는 착용 전 평균값 3.38±0.79점, 착용 후 평균값 4.33±0.54점으로 나타났으며, 통계적 분석은 유의확률이 0.002으로 유의한 결과를 보였다. 결 론 : 폴리스티렌은 MRI 이미지 신호에 영향이 없고 위생적이며 가볍고 인체에 적용하기 쉽다. 공기와 인체조직 간의 자 화율 차이를 보상할 수 있는 폴리스티렌 보정물을 이용한다면 fat suppression을 개선하여 진단적 가치가 높은 영상을 구현 할 수 있을 것으로 사료된다.

The mobility of the tactical vehicle is important for a mission completion and survivability. During the field operation of the MLRS(Multiple Launcher Rocket System), broken bolt was found in a final reduction gear with oil leakage. It was confirmed that the final reduction gear pad bolt was broken with ductile fracture after inspecting and scanning electronic microscope of the bolt. Furthermore, a finite element analysis on the bolt was conducted with regards to the operating conditions in the final reduction gear. Conducting the analysis, there was a possibility of the bolt being damaged when we put rusty spline and the adhesion of hub thrust pad as input parameters. Finally, improvements on the spline in the shaft are expected in the future by utilizing the result of this study.

The side wall thickness variation of the product to the process of ironing and the die pad was studied using a progressive die of the multi-stage drawing product in the process of ironing and the die pad. Experimental results because ironing is possible to increase the side wall thickness of the product is applied to the intermediate drawing process rather than applied in the initial process. The roundness and concentricity were easy control. A die pad is applied to a stand pad to the sixth step from the first step. The seventh step and the eighth step are applied integrated pad. The integrated pad of the seventh step and the eighth step appeared to be advantageous to control the roundness and concentricity.

Using a progressive die of the multi-stage drawing product, It was experiments for the Influence of the Products Roundness on the die pad process Safety die model, obstacle countermeasure research safety die design When the die pad is independent structure, Sidewall thickness of the inside 2stage, 3stage, 4stage of the product is thicker, the thickness of the inside 1stage and the bottom is thinner. it was become unstable beacuse the inside 1stage related to the Products Roundness is thinner. When the die pad is Integrated structure, Sidewall thickness of the inside 1stage, 2stage of the product is thicker, and Sidewall 3stage and 4stage was a thin. it was become unstable beacuse the inside 3stage related to the Products Roundness is thinner. Therefore, The appropriate combination of and integrated independent is required for each process.

Peripheral ameloblastoma, a rare and unusual variant of odontogenic tumor, representing 1% of all ameloblastomas. The extraosseous location is the peculiar feature of this type of tumor, which is otherwise similar to the classical ameloblastoma. This paper describes a case of peripheral ameloblastoma in a 43-year-old female affecting the left retromolar pad area of the mandible which was clinically diagnosed as a pyogenic granuloma. Histologically, the tumor showed of follicular ameloblastoma in continuity with a surface oral epithelium.

The automotive industry is moving from the internal combustion engine to electric drive motors. Electricmotors uses a high voltage system requiring the development of resources and components to shield the system. There-fore, in this study, we analyze electromagnetic interference (EMI) shielding effectiveness (SE) characteristics of an autocrash pad according to the ratio of electrically conductive materials and propylene. In order to combine good mechan-ical characteristics and electromagnetic shielding of the automotive crash pad, metal-coated glass fiber (MGF) manufac-turing methods are introduced and compared with powder-type methods. Through this study, among MGF methods, wesuggest that the chopping method is the most effective shielding method.