Submarining is a phenomenon in that the lap belt goes over the pelvis of the occupant during a frontal crash. It is known to be one of the causes of serious abdominal injuries for the belted occupant. The goal of the current study was to investigate the effect of both the belt geometry and dummy variations on the occurrence of submarining. A series of quasi-static belt-pull tests were performed to evaluate the influence of the parameters on the occurrence of the submarining. The main influencing factor of the submarining was the lap belt angle. The tear or wrinkle of the dummy clothing and torso angle relative to the pelvis also affected the propensity of the submarining. Therefore, these parameters need to be closely monitored to obtain repeatable test results.

Recently, due to the rapid increase in vehicle accidents, research on improving seat belts and restraint system are being actively on going to solve the problems in vehicle for passengers. The characteristics of lap belt load and pelvic displacement were simulated through MADYMO program using Hybrid III 50th percentile male dummy to analyze the submarining by changing the collision speed and seat back angle by applying the forward collision pulse form accident scenario. As a result, the submarining occurred when the seat-back angle was 60° or higher at the collision speed of 50km/h or higher. Lastly, using the characteristics of the lap belt load and pelvic displacement when the anti-submarining belt (ANSB) system adapted, the pelvic displacement was reduced as well as submarining.

In order to find out the management and sanitation status of protective gear provided at the construction site, a case study and survey were conducted by visiting the site. As a result of the case study, inspection and management, disinfection, and storage of protective equipment were insufficient in both workplaces with less than 50 employees and workplaces with more than 100 employees. As a result of the survey, workers(66.2%), said they did not know how to identify hard hats(67.6.%), how to identify bad hard hats(60.8%), and how to identify bad safety belts (73.0%), even though workers(66.2%) were educated on protective gear, and those in charge of protective gear Non-specified(56.8%), regular inspection of the provided protective equipment was not performed(82.4%), and disinfection was not performed(90.5%). Therefore, as a management plan to maintain the performance of personal protective equipment, educational aspects, regular training on protective equipment, training on how to identify defective protective equipment, management of recording papers, technical aspects, strengthening of standards for placement of dedicated safety managers in small workplaces, participation of workers’ representatives when selecting protective equipment, and selection of protective equipment for workers Providing opportunities, administrative aspects of protective equipment regulation and management, introduction of sanitary and cleanliness system, and selection of personnel in charge of protective equipment management were suggested.

요즘은 건강을 위한 스마트 헬스 케어 웨어러블의 개발이 가속화되는 시대이다. 그 중 활발한 연구 분야 중 하나인 EMS 전기자극을 활용한 웨어러블 제품이 많이 출시되었다. 하지만 연구되거나 출시되어있는 EMS 웨어러블은 근육의 세분화에 집중하지 못한 포괄적인 전신 슈트나 복부 전체를 덮는 벨트 형식으로 출시되어있다. 이에 본 연구에서는 특정 근육을 세분화시킨 EMS 패턴을 적용하고 복압 벨트에 호흡을 측정할 수 있는 스트레치 센서를 부착하여 두 가지 호흡법을 활용해 연구를 진행하고자 한다. 측정방법은 들숨과 날숨으로 실험을 진행하며 대상자는 건강한 신체의 20대 남성 10명을 대상으로 진행했다. 본 연구의 결과 흉식호흡과 복식호흡 모두 센서의 민감도는 5mm, 3mm, 기본 센서 순으로 센서별 순위 결과를 확인할 수 있었고 EMS 복압 벨트를 통해 전기자극을 적용 전, 후로 나누었을 때전기자극을 적용한 후 호흡의 활성화가 향상되었음을 알 수 있었다. 연구의 결론은 2가지 호흡법을 신체 기능적 근거로 제작한 2가지 패턴으로 인해 호흡법에 적합한 전기자극을 적용 시 적용하지 않았을 때 보다 3가지 센서로 호흡 활성화 효과와 센서 간 민감도 차이를 확인할 수 있었다. 본 연구 결과를 기반으로 후속 연구에서는 EMS 패턴과 스트레치 센서가 통합된 의복형 웨어러블 제품에 실시간 모니터링이 가능한 호흡 스마트 의류를 개발하고자 한다.

To improve the shortcomings and expand the advantages of the single-roll melt drag method, which is a type of continuous strip casting method, the melt drag method with a molding belt is applied to AZ31 magnesium alloy. By attaching the forming belt to the melt drag method, the cooling condition of the thin plate is improved, making it possible to manufacture thin plates even at high roll speed of 100 m/min or more. In addition, it is very effective for continuous production of thin plates to suppress oxidation of the molten metal on the roll contact surface by selecting the protective gas. As a result of investigating the relationship between the contact time between the molten metal and the roll and the thickness of the sheet, it is possible to estimate the thickness of the sheet from the experimental conditions. The relationship between the thin plate thickness and the grain size is one in which the thinner the thin plate is, the faster the cooling rate of the thin plate is, resulting in finer grain size. The contact state between the molten metal and the roll greatly affects the grain size, and the minimum average grain size is 72 μm. The thin plate produced using this experimental equipment can be rolled, and the rolled sample has no large cracks. The tensile test results show a tensile strength of 303 MPa.

본 연구의 목적은 해부학적 근거로 제작한 5가지의 EMS 요추 복압 벨트가 요추 안정화에 미치는 영향을 연구하는 것이다. 본 연구는 요방형근, 척추세움근, 내복사근, 외복사근, 대요근으로 총 5가지의 코어 근육을 선정하여 이에 맞는 근육 모양과 통증 유발점인 압통점을 고려해 전도성 원단으로 패턴을 설계하여 복압 벨트에 결합했다. 총 4가지 동작으로 실험을 진행하여 각각 다른 EMS복압 벨트가 요추 안정화에 미치는 영향을 알아보았다. 건강한 신체의 20대 남성 5명을 대상으로 진행하였고 선정 조건은 최근 3개월 동안 요통 과거력이 없고 사전 검사를 통해 제한되는 동작이 없고, 체간의 근력이 정상등급에 속한 대상이다. 실험 동작의 순서는 하지직거상 검사, 좌전굴, 체전굴, 배근력으로 다음 동작에 제한되지 않게 선정하였다. 동작 간의 휴식은 2분으로 진행하였고, EMS복압 벨트를 착용 후 실험을 진행할 때는 혈류량 증가와 근 활성화를 위해 전기자극을 10분씩 적용하고 진행하였다. 실험 결과의 통계는 비모수 검정으로 윌콕슨 검정과 프리드만 검정을 실시함으로 구체적인 차이를 분석하였다. 본 연구의 결과 5가지의 패턴 중 5,4,3,1,2 순으로 Type별 순위 결과를 확인할 수 있었으며 각 근육의 움직임과 연관성이 있는 실험 동작에 조금 더 유의미한 결과를 확인할 수 있었다. 본 연구의 결론은 해부학적 근거로 제작된 패턴으로 인해 각 근육에 각기 다른 모양으로 전기자극을 전달하였을 때 구분되는 효과를 확인할 수 있었으며 일반인 대상으로 일상생활이나 트레이닝에 있어 요추 안정화를 향상할 수 있을 것으로 기대된다.

식재된 수목이 활착되기 위해 소요되는 시간은 수종별로 차이가 있기 때문에 개별 수종에 대한 생장량 변동 추이 분석을 통해 관리 기간을 설정할 필요가 있다. 이에 본 연구는 수변생태벨트 조성 지역에 식재된 소나무의 연간 생장량 변화 분석 자료를 바탕으로 관리 기간을 제안하고자 하였다. 생장량을 분석한 결과, 식재 전에는 평균 0.6㎝, 식재 후 1~2년차 0.3㎝, 3~4년차 0.5㎝, 5년차 이후에는 약 0.7㎝ 내외였다. 식재된 소나무의 생장량은 1~2년차 생장 불량, 3~4년차 회복 단계를 거쳐, 5년차부터 정상 생장 단계가 확인되었기 때문에 활엽수와는 달리 최소 4년은 집중관리가 필요한 기간으로 판단되었다. 수목별 활착에 필요한 기간은 차이가 있을 수 있기 때문에 생장량 연구를 통해 수종별 관리 기간을 설정해야 할 것이다.

The purpose of this study is to investigate the current status of firefighting seatbelt use and factors affecting the wearing seatbelt of firefighters. The seatbelt use of citizens was also studied for comparative study. Two T-tests were conducted to confirm the characteristics of firefighters’ safety belts wearing firefighters. As a result, there was a statistically significant difference, on seatbelt use in general vehicles, between firefighters and citizens. And a significant difference between fire vehicles and general vehicles, on firefighters’ seatbelt use, and the average was lower in fire vehicles. Factor analysis, reliability analysis, correlation analysis and multiple regression analysis were conducted to 10 influential factors affecting seatbelt use of firefighters’. And factor analysis and reliability analysis revealed two major factors (Physical factors, Learning factors). In multiple regression analysis, it was confirmed the two independent factors had a positive effect on the dependent variable, the rate of seatbelt use of firefighters’.

Background: Improvement of lumbo-pelvic stability can reduce the compensatory action of the quadratus lumborum (QL) and selectively strengthen the gluteus medius (GM) during side-lying hip abduction (SHA). There are abdominal draw-in maneuver (ADIM) and abdominal bracing (AB) as active ways, and pelvic compression belt (PCB) as a passive way to increase of lumbo-pelvic stability. It is necessary to compare how these stabilization methods affect the selective strengthening of the GM. Objects: To investigate the effects of ADIM, AB, and PCB during SHA on the electromyography (EMG) activity of the GM, QL, external oblique (EO) and internal oblique (IO), and the GM/QL EMG activity ratio. Methods: A total of 20 healthy male adults participated in the study. The subjects performed three conditions in side-lying in random order: SHA with ADIM (SHA-ADIM), SHA with AB (SHA-AB), and SHA with PCB (SHA-PCB). To compare the differences among the three conditions, the EMG activities of the GM, QL, EO and IO, and GM/QL EMG activity ratio were analyzed using one-way repeated ANOVA. Results: The EMG activity of the QL was significantly higher in SHA-AB than in SHA-ADIM and SHA-PCB. The GM/QL activity ratio was significantly higher in SHA-PCB than in SHA-ADIM and SHA-AB. In addition, the figure for SHA-ADIM was significantly higher than that for SHA-AB. In the case of the EO, the figure for SHA-AB was significantly higher than corresponding values for the other two conditions. The figure for SHA-ADIM was significantly higher than that for SHA-PCB. The EMG activity of the IO was significantly higher in SHA-AH than in SHA-PCB. Conclusion: It can be suggested that wearing the PCB can more selectively strengthen the GM than to perform ADIM and AB during SHA. In addition, the ADIM can be recommended when there is a need to strengthen abdominal muscles during SHA.

This paper uses finite element analysis to analyze the equivalent stress and fatigue duration distributed in the timing belt pulley of the rotating part. The pulley structure used for analysis was categorized into one body type and separate axis type and their characteristics were analyzed when materials S45C and SCM440-870C were applied. A static structural analysis and durability analysis show that when external forces are applied to the pulley, the separate axis structure is structurally safer and more favorable in terms of fatigue, compared to the one body. In addition, the separate axis structure using SCM440-870C material was found to have the best safety factor at 10.4 and infinite fatigue life. These findings are expected to be useful when manufacturing timing belt pulleys.

Background:To improve lumbo-pelvic stability, passive support devices (i.e., a pelvic belt) are recommended clinically. Nevertheless, to understand the influence of passive support on lumbo-pelvic stability, it is necessary to examine the influence of a pelvic belt on the abdominal and hip abductor muscles.Objects:To examine the effects of a pelvic belt on the forces of the hip adductor and abductor muscles and activity of the abdominal muscles during isometric hip adduction and abduction.Methods:This study recruited 14 healthy men. All subjects performed isometric hip adduction and abduction with and without a pelvic belt in a neutral hip position. Load cells, wrapped with a non-elastic belt, were placed above the medial and lateral malleoli of the dominant leg to measure the muscle forces of the hip adductors and abductors, respectively. The forces of the hip adductors and abductors were measured using a load cell during isometric hip adduction and abduction, while the electromyographic activities of the bilateral rectus abdominis, internal oblique, and external oblique muscles were measured.Results:The forces generated by the hip adductors and abductors were significantly greater with the pelvic belt than without (p<.05). No significant differences in abdominal muscle activities between the two conditions were found (p>.05).Conclusion:These findings suggest that use of a pelvic belt could lead to effective strengthening exercise of hip muscles in individuals with sacroiliac joint pain.

원유나 벙커C유와 같은 지속성 기름이 해상에 유출되면 풍화과정을 거쳐 점도가 높아지고, 부유 쓰레기와 섞이게 되면 이를 수거할 수 있는 장비는 매우 제한적이다. 본 연구에서는 기존 유회수기의 외부에 위치한 부속장치들을 본체 내부로 배치하고, 컨베이어 벨트와 강제유입장치인 스위퍼 및 부력체를 탑재한 수집조로 구성하여 자항과 리모트컨트롤이 가능한 무인 컨베이어 벨트식 부유쓰레기 및 고점도유 회수장비를 개발하였다. 실해역 테스트에서 30 m의 거리를 1.2 knots의 속도로 자항하며, 전 후, 좌 우에서 안정적인 균형유지와 구동부의 정상작동을 확인하였다. 임시저장조를 이용한 유회수 성능테스트 결과, 최소 7.8 ㎘/h에서 최대 23.3 ㎘/h까지 유출유 회수가 가능하였다. 또한, 페트병 등 부유쓰레기와 유출된 기름이 혼합된 조파수조에서 실시한 회수량 측정 테스트 결과는 7.7 ㎘/h로 나타났다. 본 연구를 통해 개발된 장비가 해상기름오염사고 시 현장에 신속하게 투입된다면 방제능력 향상에 기여할 수 있을 것으로 기대하며, 현재 운용중인 Portable 유회수기의 성능개선 연구에 활용될 수 있을 것으로 판단된다.

The purpose of this study was to investigate the dynamic balance and activity of internal oblique muscle, multifidus muscle, gluteus maximus muscle, biceps femoris muscle during the Y balance test following the wearing of pelvic compression belt. Forty healthy adults were recruited for this test. The dynamic balance score was estimated as the following: (anterior+posteromdial+posterolateral)/(3×leg length)×100. The electromyography signals were measured through %reference voluntary contraction, which was normalized by reference voluntary contraction of Y balance test without wearing the pelvic compression belt. The paired t-test was carried out to compare the dynamic balance score and the activity of the trunk and hip extensor with and without the wearing of pelvic compression belt. The dynamic balance score of the Y balance test when wearing pelvic compression belt was significantly than when measured without wearing the pelvic compression belt (p<.05). The muscle activity of the internal oblique and the multifidus was significantly decreased when wearing pelvic compression belt (p<.05). The muscle activity of the gluteus maximus was significantly increased when wearing pelvic compression belt (p<.05). However, there was no significant difference in hamstring muscle activity, with or without wearing the belt (p>.05). In conclusion, this study shows that the wearing of pelvic compression belt affects trunk muscle and hip extensor muscle activity related to the pelvic mobility and stability and increases dynamic balance and also contributes to the stabilization of the external pelvic stabilization.