• 농업생명과학연구
• /
• 제46권1호
• /
• pp.35-41
• /
• 2012

공진주파수 모드를 이용하는 비파괴 평가기술법을 닥나무를 소성온도별(600, 800, 1000, $1200^{\circ}C$)로 제조한 우드세라믹에 적용하였다. 공진주파수 및 동적 탄성계수는 소성온도가 증가할수록 증가하였다. 동적 탄성계수 및 정적 휨 탄성계수와 휨강도사이에는 밀접한 상관관계가 나타났다. 따라서 공진 주파수 모드를 사용하는 동적 탄성계수측정은 소성온도에 따라 제조된 우드세라믹의 휨강도를 예측하는 비파괴 평가 방법으로 유용할 것으로 판단된다.

• 대한간호학회지
• /
• 제49권5호
• /
• pp.515-525
• /
• 2019

Purpose: This study aimed to evaluate the effectiveness of a customized health promotion program (CHPP) on depression, cognitive functioning, and physical health of elderly women living alone in the community. Methods: A randomized comparison of pre-and post-test design was used with 62 participants assigned to either an intervention (n=32 in seven clusters) or a control group (n=30 in seven clusters) in 14 areas of a town. The final sample included 30 intervention participants who completed the CHPP for 10 weeks, and 26 control participants. The intervention group participated in the CHPP weekly; they were provided with instructions about coping with their chronic illnesses, lifestyle modification, risk management, providing emotional support to each other, and floor-seated exercise, which they were encouraged to do three times a week in their homes. Results: Significant group differences were found in depression (U=48.50, p<.001), cognitive functioning (U=2.50, p<.001), left arm flexibility (U=251.50, p=.023), right arm flexibility (U=225.00, p=.007), static balance (U=237.00, p=.012), and gait ability (U=190.50, p=.004). However, there were no significant differences in bothgrip strength and muscle mass between the two groups. Conclusion: The findings indicate that CHPP was overall effective at improving depression, cognitive functioning, and physical functioning of elderly women living alone, and could therefore be considered a positive program for community-dwelling elderly women living alone.

• 대한조선학회논문집
• /
• 제31권3호
• /
• pp.129-134
• /
• 1994

레이저 절단기는 고도의 정밀을 요하는 선체구조강판의 가공용으로 최근 조선소에서 사용되게 되었으며, 정밀성 유지를 위해서 이 시스템 자체의 운동으로 인한 변형은 일정한도 내에서 유지되어야 한다. 본 논문에서는 새로 개발된 레이저 절단기의 모드해석 및 구조해석을 이 시스템의 설계요구조건에 부합하는지를 검토하기 위하여 수행하였으며, 이를 위하여 유한 요소 모델링의 효과적인 기법과 가상 질량요소를 분대하는 기법, 가속도장의 변화로 주어지는 외력조건의 구체화 방법등을 제시하였다. 또한 고유진동해석을 수행하여 이 시스템의 동적효과 존재 여부를 검토하였으며 시간영역의 동적해석을 하지 않고 정적해석을 통한 시스템 특성 규명 타당성을 규명하였다. 해석 접근 방법의 유용성이 입증되었으며 결과적으로 본 논문에서 보여 준 해석기법은 유사한 시스템의 특성 규명에 유효하게 적용될 수 있음을 시사하고 있다.

• 사상체질의학회지
• /
• 제33권3호
• /
• pp.29-53
• /
• 2021

Objective The purpose of this review was to investigate exercise therapy by sasang constitution and to offer information for further research. Method The literature was investigated from KMBASE, KISS, ScienceON, JSCM, DBpia, Pubmed. The searching term were sasang, sasang constituion, sasang type, taeyangin, taeeumin, soyangin, soeumin, exercise, physical therapy, physical activity, and so on. Studies were extracted and analyzed exercise by sasang constitution, in addition, were also collected physiological differences related to sasang constitution, exercise ability, exercise response and effects, and exercise contraindications. Result & Conclusion It is helpful for Taeyangin to lower the energy through exercises that train the lower body and deep breathing, and there is no need to exercise excessively. Taeeumin tend to be obese compared to other constitutions. In order to be physically healthy, it is good to sweat a lot through regular exercise. It is good to do aerobic exercise that burns a lot of calories every day. Soyangin has a weak lower body, so it is good to exercise to reinforce the lower body. Soyangin has weak stamina, and since static exercise easily loses interest, it is helpful to do exciting exercise, and it can be performed at normal intensity. Soeumin are statistically less physically active. So soeumin need to improve exercise habits, but because physical strength is on the weak side, it is more appropriate to do an exercise that activates the body parts evenly rather than a strong one.

• Structural Engineering and Mechanics
• /
• 제69권6호
• /
• pp.627-635
• /
• 2019

In order to study the axial compression performance of sand-lightweight concrete-filled steel tube (SLCFST) stub columns, three circular SLCFST (C-SLCFST) stub column specimens and three SLCFST square (S-SLCFST) stub column specimens were fabricated and static monotonic axial compression performance testing was carried out, using the volume ratio between river sand and ceramic sand in sand-lightweight concrete (SLC) as a varying parameter. The stress process and failure mode of the specimens were observed, stress-strain curves were obtained and analysed for the specimens, and the ultimate bearing capacity of SLCFST stub column specimens was calculated based on unified strength theory, limit equilibrium theory and superposition theory. The results show that the outer steel tubes of SLCFST stub columns buckled outward, core SLC was crushed, and the damage to the upper parts of the S-SLCFST stub columns was more serious than for C-SLCFST stub columns. Three stages can be identified in the stress-strain curves of SLCFST stub columns: an elastic stage, an elastic-plastic stage and a plastic stage. It is suggested that AIJ-1997, CECS 159:2004 or AIJ-1997, based on superposition theory, can be used to design the ultimate bearing capacity under axial compression for C-SLCFST and S-SLCFST stub columns; for varying replacement ratios of natural river sand, the calculated stress-strain curves for SLCFST stub columns under axial compression show good fitting to the test measure curves.

• 한국구조물진단유지관리공학회 논문집
• /
• 제23권1호
• /
• pp.85-93
• /
• 2019

프리캐스트 바닥판 공법은 바닥판간 이음부가 존재하며, 이음부의 연결성능에 따라 전체 교량 구조물의 성능이 좌우되므로 이음부의 연결성능 확보가 중요한 요소이다. 특히, 교량바닥판은 차량하중과 같은 반복하중을 받는 구조물이므로 피로하중에 대한 이음부의 거동 및 성능평가가 이루어져야 한다. 본 연구에서는 비대칭 요철형 루프이음을 적용한 2거더 연속합성형 교량을 제작하여 정적 및 200만회 반복하중의 피로실험을 통해 프리캐스트 바닥판의 구조적 거동 및 균열양상을 검토하였다. 실험결과, 제안된 프리캐스트 바닥판 연결시스템은 균열 폭, 누수, 인장철근의 응력 등 충분한 피로성능 및 파괴강도를 확보하는 것으로 나타났으며, 프리캐스트 바닥판 이음부에 효과적으로 적용 가능할 것으로 판단된다.

• 한국항공우주학회지
• /
• 제47권8호
• /
• pp.599-606
• /
• 2019

펄스건 장치는 연소실 내, 다중 분사기 배열에 따른 연소 유동장으로의 횡단 압력파 전파/감쇠 메커니즘 규명을 목적으로 제작되었다. 제작된 펄스건은 성능시험을 통해 목표 연소압에서의 운용 가능 여부와 압력파 강도 제어 여부를 확인하였다. 기체질소를 사용하여 고압관에 가압을 하였으며 다이아프램에는 $100{\mu}m$ 두께의 OHP 필름을 사용하였다. 압력파의 속도와 강도를 확인하기 위해 압력 트랜스듀서를 이용하여 동압과 정압을 측정하였다. 제작된 펄스건은 공급압력에 따라 압력파의 강도 조절이 가능하며 횡방향성을 가지는 압력파를 생성할 수 있음을 성능시험을 통해 확인하였다.

• Structural Engineering and Mechanics
• /
• 제70권6호
• /
• pp.703-710
• /
• 2019

While fiber-reinforced plastic (FRP) materials have been largely used in the retrofitting of concrete buildings, its application has been limited because of some problems such as de-bonding of FRP layers from the concrete surface. This paper is the part of a wide experimental and analytical investigation about flexural retrofitting of reinforced concrete (RC) columns using FRP and mechanical fasteners (MF). A new generation of MF is proposed, which is applicable for retrofitting of RC columns. Furthermore, generally, to evaluate a retrofitted structure the nonlinear static and dynamic analyses are the most accurate methods to estimate the performance of a structure. In the nonlinear analysis of a structure, accurate modeling of structural elements is necessary for estimation the reasonable results. So for nonlinear analysis of a structure, modeling parameters for beams, columns, and beam-column joints are essential. According to the concentrated hinge method, which is one of the most popular nonlinear modeling methods, structural members shall be modeled using concentrated or distributed plastic hinge models using modeling parameters. The nonlinear models of members should be capable of representing the inelastic response of the component. On the other hand, in performance based design to make a decision about a structure or design a new one, numerical acceptance should be determined. Modeling parameters and numerical acceptance criteria are different for buildings of different types and for different performance levels. In this paper, a new method was proposed for FRP retrofitted columns to avoid FRP debonding. For this purpose, mechanical fasteners were used to achieve the composite behavior of FRP and concrete columns. The experimental results showed that the use of the new method proposed in this paper increased the flexural strength and lateral load capacity of the columns significantly, and a good composition of FRP and RC column was achieved. Moreover, the modeling parameters and acceptance criteria were presented, which were derived from the experimental study in order to use in nonlinear analysis and performance-based design approach.

• 한국응용과학기술학회지
• /
• 제37권6호
• /
• pp.1728-1737
• /
• 2020

본 연구는 운동 형태에 따른 여성 노인들의 건강관련체력 변화를 규명하여 만성질환을 관리하고 상해를 예방하는데 도움을 주는 운동을 선택하는데 자료를 제공하는데 있다, B 광역시에 거주하는 72-78세의 노인여성을 통제그룹 10명, 유산소 운동그룹 10명, 저항 운동그룹 10명, 복합 운동그룹 10명으로 분류하여 8주간 주 3회, 50분/회 운동을 실시하였다. 운동 강도는 모든 운동그룹에 동일하게 RPE 11-13으로 설정하였다. 하지근력, 동적평형성, 정적평형성, 그리고 민첩성은 모든 운동 그룹에서 운동 후 유의하게 향상된 결과를 보였으나, 심폐지구력은 유산소 운동 그룹과 복합운동그룹에서만 운동 후 향상된 결과가 나타났다. 결론적으로 여성 노인들에게 운동 강도가 같다면 어떠한 운동 형태든지 일상생활과 관련된 체력의 향상에 도움을 줄 수 있는 것으로 확인되었으며, 복합 운동이 노인들에게 보다 적합한 운동 형태라 할 수 있을 것이다.

• 한국기계가공학회지
• /
• 제20권1호
• /
• pp.80-87
• /
• 2021

Most container ships are currently being constructed as Ultra-Large Container Ships. Hence, the equipment of the ships is also becoming relatively large. In particular, propellers, rudders, and rudder stocks are large in the stern structure, and in relation, efficient design of the hull structures to safely secure these parts is important. The bottom shell plate surface of a stern skeg is a perforated plate from which the rudder stock penetrates, so it is an important component for the stern structure. In this paper, to determine the critical buckling of the shell plate, an interaction curve equation for the two-axis compression of the shell plate was derived using the maximum value of the static structural stress multiplier in a load multiplier mode. This equation predicts the timing of the buckling occurrence. By analyzing this interaction curve equation, the buckling behavior of the plates subjected to a combination load was determined and the usefulness of applying it to ship building was investigated.