이 연구는 시설 내 노인학대의 지속적 증가와 구조적 요인에 주목하여, 시설 환경에 서 발생하는 노인학대의 구조적 특성과 교정적 개입 방안을 다각도로 분석하였다. 민･ 형사･행정 판례와 최근 국내외 선행연구를 종합 분석한 결과, 시설 내 노인학대는 인 력 부족, 낮은 근로환경, 조직문화의 결함, 감독 시스템 부재 등 복합적 구조적 요인이 작용함이 확인되었다. 특히 방임, 신체적･정서적･경제적 학대, 성적 학대 등이 반복 적･조직적으로 발생하고 있으며, 신고･처벌 위주의 기존 대응은 실질적 예방과 재발 방지에 한계가 있는 것으로 나타났다. 이에 본 연구는 구조적 개선과 함께, 가해자 대 상 교정적 프로그램 개발, 조직문화 혁신, 직원 교육 강화 등 다양한 정책적･실천적 제언을 제시하였다. 본 연구는 실효성 있는 예방 및 재발 방지 대책 마련에 기초 자료 로 활용될 수 있을 것이다.

In order to revitalize the marine leisure industry, researches on various leisure vessels have been widely conducted in Korea. In particular, in the field of leisure sports, researches and developments for improving the performance of high-speed motorboats are actively progressing. For reducing the weight of motorboats various composite materials are applied to the hull, and these composite materials must ensure structural safety. In this study, the material properties of composite materials applied to tunnel-type motorboats, used in the OSY(Outboard Stock Yamato)-400 race, were evaluated and the structural analysis was performed to examine the safety of the motorboat hull. Material tests were conducted according to Korean Industrial Standard and structural analysis of finite elements model of the motorboat hull was performed under longitudinal bending and torsional load conditions, respectively. By comparing the analysis results with the material test results, it was confirmed that the applied composite material meets the required strength.

고밀도폴리에틸렌(HDPE)은 대표적인 열가소성 플라스틱으로서 재활용성, 내충격성 등이 우수하여 차세대 친환경 소형선박용 재료로 각광받고 있다. 그러나, HDPE의 열변형온도는 하절기의 선체 온도와 비슷한 수준이며, 재료의 열팽창 특성으로 인해 선박 구조용 재료로서의 적용 가능성에 대한 기술적 검토가 필요하다. 본 연구에서는 선박이 일상적으로 겪을 수 있는 상온 이상 온도범위에서 HDPE 의 기계적·열적 물성치를 도출하였고, 모의설계한 HDPE 어선을 대상으로 연중 태양복사열과 기관실 내부 온도가 가장 높은 하절기 운용 상황을 모사한 열전달 해석을 통해 구조부재들의 온도변화 및 분포, 응력 및 변위 구배 등을 확인하고자 하였다. 혹서기의 높은 기온과 강한 태양복사에 노출되는 HDPE 선체의 온도는 재료의 열변형온도 수준까지 상승하며 열팽창에 의한 변형 및 국부응력을 보여 설계 및 검토단계에서 선체 변형을 고려할 필요가 있고 향후 선체변형 대응방안 및 구조안전성 평가기준 마련 시 온도상승에 따른 물성치 변화를 고려할 필요가 있다.

In the development of eco-friendly vehicles such as electric vehicles, weight reduction has become a very important design target. Seat weight reduction is very important in vehicle weight reduction. In this study, the energy absorption characteristics of Almag material, an alloy of aluminum and magnesium, and mild steel SAFH440, SAFH590, SAFC780, and SAFH980 were analyzed to obtain a true stress versus true strain curve that was correlated with the test. By performing the seat frame structure analysis using the obtained analysis material property, it was possible to compare the deformation between lightweight material, Almag and mild steel materials. In addition, it was confirmed that the weight reduction effect was 25.8% when applying Almag, an equivalent lightweight material that gives the same maximum deformation as SAFH980, a high-strength mild steel.

The cultural heritage of fortresses is often exposed to external elements, leading to significant damage from stone weathering and natural disasters. However, due to the nature of cultural heritage, dismantling and restoration are often impractical. Therefore, the stability of fortress cultural heritage was evaluated through non-destructive testing. The durability of masonry cultural heritages is greatly influenced by the physical characteristics of the back-fille material. Dynamic characteristics were assessed, and endoscopy was used to inspect internal fillings. Additionally, a finite element analysis model was developed considering the surrounding ground through elastic wave exploration. The analysis showed that the loss of internal fillings in the target cultural heritage site could lead to further deformation in the future, emphasizing the need for careful observation.

Traditional piles used for deep foundation, such as steel, concrete, and timber, are susceptible to corrosion and a reduction in structural capacity over time. This has led to the development of new materials like concrete-filled FRP piles (CFFP). CFFP is a composite pile filled with concrete and covered with a fiber-reinforced plastic (FRP) shell, providing non-corrosive reinforcement and protection to the concrete. As a result, CFFP is a highly promising candidate for implementation in various fields due to its structural advantages and necessity. Compared to traditional concrete piles, CFFP can be installed with less damage and a lower blow range due to its elastic modulus, damping ratio, and specific weight. The bearing capacity of a pile is influenced by various factors, including its stiffness, residual stress, and axial load resistance. Due to competitive pricing, glass fiber has been widely utilized, and there is a growing interest regarding carbon-fiber-reinforced concrete piles due to the excellent mechanical properties of carbon fiber. The remarkable stiffness and strength attributes of carbon fibers are evident in CFRP-confined piles, which present a notably wide range of load-bearing capacities, boasting an ultimate axial load capacity ranging from 500 to 4000 kN. Furthermore, CFFPs have been confirmed to have superior lateral load resistance compared to conventional piles, attributed to the reinforcement provided by FRP materials. Conventional piles face a challenge in that their structural characteristics deteriorate in the corrosive marine environment, with a projected lifespan of less than 20 years. In contrast, the service life of CFFPs is estimated to range from 50 to 75 years.

In this study, we designed and manufactured a large angular contact ball bearing (LACBB) with low deformation using JIS-SUJ2 steel and analyzed changes in its structural characteristics and chemical composition upon heat treatment. The bearing was produced by hot forging and heat treatment including a quenching and tempering (Q/T) process, and its properties were analyzed using 4 mm thick specimens. A difference in the size distribution of the carbide in the outer and inner parts of the bearing was observed and it was confirmed that large and non-uniform carbide was distributed in the inner part of the bearing. After heat treatment, the hardness value of the outer part increased from 13.4 HRC to 61 HRC and the inner part increased from 8.0 HRC to 59.7 HRC. As a result of X-ray diffraction (XRD) measurements, the volume fraction of the retained austenite contained in the outer part was calculated to be 3.5~4.8 % and the inner part was calculated to be 3.6~5.0 %. The surface chemical composition and the content of chemical bonds were quantified through X-ray photoelectron spectroscopy (XPS), and a decrease in C=C bonds and an increase in Fe-C bonds were confirmed.

The design of buried underground flexible pipes proposed in domestic standards does not properly reflect changes in ground characteristics. Overseas standards suggest that pipe deflection must be considered while designing them. Therefore, in this study, the structural behavior of underground polyvinyl chloride pipes was investigated through experiments and the finite element analysis. In addition, when the pipe deflection occurred at 3% and 5%, the hydraulic characteristics of the polyvinyl chloride pipe showed a slight difference compared to the round pipe.

This study examined the structural characteristics of the royal tomb equipped with only rail stones in the early Joseon Dynasty. Bongneung(封陵: the burial mound of royal tomb) equipped with only rail stones was constructed from 1468 to 1632. During this period, Hyeongung(玄宮: the underground chamber for the coffin of the king or queen) was constructed with lime. When the Hyeongung is completed, the soil is covered with a thickness of 1 foot parallel to the ground surface. On top of that, as the base of the Bongneung, the rail ground stone is constructed with a height of about 1.5 to 2 feet. The inside of the rail ground stone is also firmly filled with soil. On top of this, semicircular lime is installed with a convex center. Lastly the soil is divided and compacted several times to form a hill, and then covered with grass to complete the Bongneung. The notable feature is that between the Hyeongung made of lime and the Bongneung made of soil, the rail ground stone serves as a stylobate with the inside compacted by the soil.

Recently, carbon composites have been applied to various fields. However, carbon composites have not been applied to the fishing vessel field due to its structure standards centered on glass composites. In this study, a structural strength evaluation study was conducted for the application of carbon composites in the fishing vessel field. Hull minimum thickness verification test and hull joint verification test were conducted. Compared to glass composites, the verification was based on equivalent or better performance. The results show that carbon composites can reduce the weight by 20% compared to glass composites. For hull joints, it was necessary to increase the thickness of the joint seam by the thickness of the hull to apply carbon composite. Through this study, a standard for the application of carbon composites to fishing vessel can be established.

Laparoscopy instrument requires blood vessel ligator to prevent blood leakage. Clip ligation device is widely used to prevent blood loss and secure surgical vision by using blood vessel ligator. However, in order to properly install the clip to the vessel ligator and ligate the blood vessel by the ligation machine, the device is properly operated and the parts constituting the jaw areas should be ensuring sufficient strength and rigidity during the operating. Therefore, the clip binding forces were calculated through a dynamic model of the blood vessel ligator. As a result, the force satisfies the target value of 8.5 N or more regardless of the grip force positions. And structural analysis was carried out to find out the maximum resistance force at the tip of the inner shaft. The maximum load was about 45.6 N, which sufficiently satisfies the development target of 40.0 N or higher.

This research examines the effect of adding aluminum on the structural, phasic, and magnetic properties of CoCrFe NiMnAlx high-entropy alloys. To this aim, the arc-melt process was used under an argon atmosphere for preparing cast samples. The phasic, structural, and magnetic properties of the samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrational magnetometry (VSM) analyses. Based on the results, the addition of aluminum to the compound caused changes in the crystalline structure, from FCC solid solution in the CoCrFeNiMn sample to CoCrFeNiMnAl BBC solid solution. It was associated with changes in the magnetic property of CoCrFeNiMnAlx high-entropy alloys, from paramagnetic to ferromagnetic. The maximum saturation magnetization for the CoCrFeNiMnAl casting sample was estimated to be around 79 emu/g. Despite the phase stability of the FCC solid solution with temperature, the solid solution phase formed in the CrCrFeNiMnAl high-entropy compound was not stable, and changed into FCC solid solution with temperature elevation, causing a reduction in saturation magnetization to about 7 emu/g.

The construction method of scaffolding structures is different from Mortise and Tenon and bucket arch structure of traditional large woodwork. It forms an independent construction system-fixing nodes with knots, a large number of diagonal braces are used to fix shelves and the structures mostly contain X-shape and triangular shape details. Simple ones include stalls, sheds, rain sheds, altars, lamp racks etc. But the scaffolding with larger scale and more complicated structure are modeled on archways, theatres and other buildings which are used in commercial and festival activities. At present, Macao, Hong Kong, Guangdong, Sichuan, Shanxi and other places in China have retained the custom of using scaffolding structures in important festival activities, but their uses, techniques and building types are slightly different from place to place. Due to building and demolishing at any time, the construction and service cycle is short. As a result, there are almost no physical objects left. We can only deduce the use and technical characteristics of ancient scaffolding skills through the colorful building styles that have been preserved with folk activities in various parts of China, the craftsmanship handed down from generation to generation by the scaffolding guild and artisans, and the description of cultural and historical materials and the mutual corroboration of visual materials.

In this study, a finite element analysis was used to analyze the stress state and vibration characteristics generated by continuous contact between wheels and rails when driving urban railway vehicles. The rails applied to the analysis were divided into straight and curved shapes, and three-dimensional modeling was performed to analyze the changes in structural characteristics of wheels and rails when driving on straight and curved rails. As a result of the analysis, the stress characteristics were up to 6.5 MPa on a straight rail and 9.81 MPa on a curved rail, and it is believed that this increase in stress will increase noise due to an increase in friction at the interface. The vibration characteristics of the wheels and rails showed similar behavior from the 3rd mode to the 9th mode of the rail to the intrinsic vibration characteristics from the 4th mode to the 6th mode of the wheel.

Barnea manilensis is a bivalve which bores soft rocks, such as, limestone or mudstone in the low intertidal zone. They make burrows which have narrow entrances and wide interiors and live in these burrows for a lifetime. In this study, the morphology and the microstructure of the valve of rock-boring clam B. manilensis were observed using a stereoscopic microscope and FE-SEM, respectively. The chemical composition of specific part of the valve was assessed by energy dispersive X-ray spectroscopy (EDS) analysis. 3D modeling and structural dynamic analysis were used to simulate the boring behavior of B. manilensis. Microscopy results showed that the valve was asymmetric with plow-like spikes which were located on the anterior surface of the valve and were distributed in a specific direction. The anterior parts of the valve were thicker than the posterior parts. EDS results indicated that the valve mainly consisted of calcium carbonate, while metal elements, such as, Al, Si, Mn, Fe, and Mg were detected on the outer surface of the anterior spikes. It was assumed that the metal elements increased the strength of the valve, thus helping the B. manilensis to bore sediment. The simulation showed that spikes located on the anterior part of the valve received a load at all angles. It was suggested that the anterior part of the shell received the load while drilling rocks. The boring mechanism using the amorphous valve of B. manilensis is expected to be used as basic data to devise an efficient drilling mechanism.

Recently, the construction of tall buildings utilized by high strength-concrete in the whole world is tending to be on the rise. The application of high-rise structural system in buildings results in the excellent cut-down effect in construction materials due to section reduction. Therefore, in order to investigate the CO2 and resource reduction effect for the high-rise structural system, comparisons of GWP and ADP in embodied energy of structural materlais between 4 type of high-rise structural system have been performed. As a result, GWP emission increased in the order of steel structure outrigger system, RC shear wall system, and RC outrigger system. On the other hand, ADP emissions increased in the order of RC shear wall system, RC outrigger system, and steel structure outrigger system.

High concentrations of fine particles are increasingly being detected due to inflows from abroad and local emission sources in Korea. As most people spend about 90% of their time indoors, the use of indoor air cleaners has grown significantly as they are now thought to be essential items. In this study, the noise, power consumption, and clean air delivery rate (CADR) of commercial air cleaners were analyzed according to the structural shape of the air cleaners. Analyses were performed based on the experimental results of 249 cases for air cleaners certified by Korea Air Cleaning Association. The air cleaners with front inlet and upper outlet air flow direction, which currently account for the highest market share, were found to have the highest noise per CADR (dB(A)/(m3/min)). On the other hand, the air cleaners with the inlet and outlet air flow in the same horizontal direction were found to have lowest noise per CADR than other structures.

Cr thin films with O added are deposited on sapphire substrate by DC sputtering and are nitrided in NH3 atmosphere between 300 and 900 oC for various times. X-ray diffraction results show that nitridation begins at 500 oC, forming CrN and Cr2N. Cr oxides of Cr2O3 are formed at 600 oC. And, at temperatures higher than 900 oC, the intermediate materials of Cr2N and Cr2O3 disappear and CrN is dominant. The atomic concentration ratios of Cr and O are 77% and 23%, respectively, over the entire thickness of as-deposited Cr thin film. In the sample nitrided at 600 oC, a CrN layer in which O is substituted with N is formed from the surface to 90 nm, and the concentrations of Cr and N in the layer are 60% and 40%, respectively. For this reason, CrN and Cr2N are distributed in the CrN region, where O is substituted with N by nitridation, and Cr oxynitrides are formed in the region below this. The nitridation process is controlled by inter-diffusion of O and N and the parabolic growth law, with activation energy of 0.69 eV.