• 한국해양공학회지
• /
• 제29권1호
• /
• pp.45-55
• /
• 2015

Because of the high stress concentration near the toe of a welded joint, the calculation of local stress using the finite element method which is relevant to the fatigue strength of the weld toe crack, is a challenging task. This is mainly caused by the sensitivity of finite element analysis, which usually occurs near the area of a dramatically changing stress field. This paper presents a novel numerical method through which a less mesh-sensitive local stress calculation can be achieved based on the 3D solid finite element, strictly sticking to the original definition of hot spot stress. In order to achieve the goal, a traction stress, defined at 0.5t and 1.5t away from the weld toe, was calculated using either a force-equivalent or work-equivalent approach, both of which are based on the internal nodal forces on the imaginary cut planes. In the force-equivalent approach, the traction stress on the imaginary cut plane was calculated using the simple force and moment equilibrium, whereas the equivalence of the work done by both the nodal forces and linearized traction stress was employed in the work-equivalent approach. In order to confirm the validity of the proposed method, five typical welded joints widely used in ships and offshore structures were analyzed using five different solid element types and four different mesh sizes. Finally, the performance of the proposed method was compared with that of the traditionally used surface stress extrapolation method. It turned out that the sensitivity of the hot spot stress for the analyzed typical welded joints obtained from the proposed method outperformed the traditional extrapolation method by far.

• 드라이브 ㆍ 컨트롤
• /
• 제17권1호
• /
• pp.21-26
• /
• 2020

The load characteristics of a piston pump holder due to the squeeze effect are influenced by the surface shape and gap thickness of the holder (cradle). Therefore, the pressure distribution and the load capacity of the piston pump holder due to the squeeze effect are studied by using the CFD software and the surface shape and gap thickness of the piston pump holder are considered. In order to verify the accuracy of numerical results, the load capacities of a circular plate holder are numerically studied, and the accuracy of numerical results is verified by comparing with the theoretical results. Also, the pressure distribution and load capacity of the rectangular plate holder of a piston pump are obtained by using the CFD software. The results show that the load capacity of the square plate holder with grooves is slightly higher at a low gap thickness, but the effects of the number and arrangement of grooves on the load capacity of the holder are weak. We conclude that the load capacity and the maximum pressure are slightly affected due to the existence of grooves on the holder surface, and the fluid storing effect of the holder surface grooves during the operation is likely to prevent the dry-sticking phenomenon.

• 대한기계학회논문집
• /
• 제19권4호
• /
• pp.968-980
• /
• 1995

Al/Al$_{2}$O$_{3}$/C hybrid metal matrix composites are fabricated by the direct squeeze infiltration method. From the microstructure of Al/Al$_{2}$O$_{3}$/C composites, uniform distribution of reinforcements and good bondings are found. Optimum processing conditions for preforms and squeeze castings are suggested. Mechanical properties, such as elastic modulus, elongation, 0.2% offset yield strength and ultimate tensile strength are obtained. Through the abrasive were test and wear surface analsis, wear behavior and its mechanism of AC2B aluminum and Al/Al$_{2}$O$_{3}$/C composites can be characterized under various sliding speed conditions. Tensile strenght elongation of Al/Al$_{2}$O$_{3}$/C composites are decreased with increasing the addition of carbon fiber. On the contrary, elastic modulus of Al/Al$_{2}$O$_{3}$/C composites is slightly improved compared with that of the unreinforced matrix alloy. The addition of carbon fiber to al/al$_{2}$O$_{3}$/C composites gives rise to improvement of the wear resistance. Specially, carbon chopped fibers play an important role in interfering sticking between the counter material and metal matirix composites. Al/Al$_{2}$O$_{3}$/C composites are suitable to high speed due to solid lubication of carbon. And wear model of Al/Al$_{2}$O$_{3}$/C composites is suggested by the examination of worn surfaces.

• 한국의상디자인학회지
• /
• 제11권2호
• /
• pp.75-84
• /
• 2009

The following research analyzed the sewing teaching of the tailored jacket shown in fashion textbooks, which are currently used in universities and educational organizations in the fashion industry. To analyze the sewing teaching of tailored jackets, we analyzed 35 textbooks in the market. Among them we used 14 textbooks which dealt with the patter formation method of tailored jackets, and cutting and sewing methods. First, the stitching direction and the location of attachment varied. The type of sticking tape and its position also differed, emphasizing the need to make an institutionalized education material which is based on the characteristic of the fabric and its silhouette. Second, controlling the ease length of the right side sewing princess line, or information about the shoulder line and sleeve line of the notch as not specifically shown in the textbooks. Furthermore, not many textbooks showed how to pull the lower part of the texture out of sight, nor did they explain why this needed to be done. Third, the lining is usually slightly larger than the outer texture of the clothing, as the lining is usually tugged in the sewing process, and this method makes the clothes more comfortable. The method of sewing the princessline $0.2{\sim}0.3cm$ outside the outer pattern was the most recommended. The center-back side was usually 2cm in activity measurements, but it turned out that a textbook which required ease treatment on the shoulder line did not do so on the lining material. The textbooks used in this research dealt only with how to manufacture a tailored jacket without full explanation about textures which could influence the manufacturing. The production method and process differed between different textbooks, showing the need to make a institutionalized education material. In a quickly-changing era where there is rapid change in the dressmaking procedure, we need to help students understand the process more easily through a formalized education process.

• 가정과삶의질연구
• /
• 제26권1호
• /
• pp.31-49
• /
• 2008

This study has been performed to explore verbal and behavioral expression of sexual desires among male elderly residents who have been living in long tenn care facilities. There are three topics covered in this study; first, in what situations and how seriously do care workers encounter expression of sexual desires of the elderly residents? Second, what kind of negative consequences do they believe those sexual behaviors will lead to? Third, how can we implement defensive measures against the sexual behaviors? In this study, twenty three care workers working full time in five retirement and care facilities were asked about their experience and perception of the above study agendas, and answers of the qualitative interview were drawn as follow; first, the elderly residents apparently show a variety of sexual harassment and provoking behaviors such as sticking to specific women, physically touching and attacking, and induce obscenely activities against female residents, care workers, and volunteer visitors. Second, their sexual behaviors are often influenced by their isolated and abandoned emotionality as well as living situation in rural areas. Third, their sexual behaviors often critically affect care work plan and facility managements by severely discouraging female care givers and community supporters. Therefore in this study, suggestions and defensive measures were made as follows: first, education and counselling programs toward female workers and volunteers need to be developed, and the programs should cover psychological and behavioral mechanism of sexuality in later life. Second, self control plans need to be empowered toward the elderly residents; in the plans, the elderly residents shall be encouraged to evaluate primary cause and proper solutions of sexual behaviors of their peering residents. Third, combination of healthy housing and care facilities for frail elderly need to be integrated in a neighboring location, so that when residents and workers encounter extreme episodes of sexuality of healthy residents in a housing facility, the problematic sexual residents are partially transferred into a neighboring care facility and thereafter other residents and cafe givers are relieved from stressful contacts with the extremely sexual residents.

• 한국식품영양과학회지
• /
• 제12권1호
• /
• pp.12-18
• /
• 1983

An ecological survey of early childhood nutrition was conducted from January 23 to February 18, to study the feeding method and weaning practice in Whaseong-gun, Kyonggi-do. This study covered a total of 283 children. Seventy three percent of the subjects had been breast-fed; 10% had been bottle-fed; others had been combination-fed before the introduction of supplementary foods. Only 26.9% of the subjects began to be fed supplementary food before the age of 6 months. The supplementary food used most frequently by the majority of children at the beginning of weaning was plain cooked rice; rarely special preparation, or different from the food eaten by the family. As for age of termination of breast feeding, 42.7% of the subjects were before 12 months; 32.8% were between 13 and 18 months of age; 24.5% were more than 19 months old. As for methods of stopping breast feeding, 44.5% of the subjects were naturally terminated while 38.5% were forced to terminate by the application of sticking plaster or medicines to the mother's nipples. The results indicate a need for nutrition and hygiene intervention to improve the weaning practice of rural area through the community nutrition education.

• 대한한방내과학회지
• /
• 제21권3호
• /
• pp.369-376
• /
• 2000

Purpose : Cerebrovascular disease is the most frequent cause of death in Korea and it remains severe disabilities disturbing normal life, According to the previous studies, mortality of the stroke in the first one week is up to the 20% and 95% of stroke patients in the acute stage are accompanied by more than one complications. These complications affect not only the acute stage mortality but also the late stage rehabilitations. In Korea the oriental medicine is preformed in the treatment of stroke. Therefore it is important to recognize thoroughly the complications in the acute stage of stroke and to prevent them. But studies about complications of acute stage stroke is rarely presented in the fields of oriental medicine. So this study is prepared for investigating the characteristics and frequency of complications in the acute stage of stroke. And we are to assess the importance of theses acute complications by systemic reviewing the previous studies. Methods : Fifty one patients are included who had been admitted to ICU(intensive care unit) of Chenju Hospital of Wonkwang Oriental Medicine. Twenty nine patients are diagnosed as ischemic stroke and twenty one patients are diagnosed hemorrhagic stroke. Medical and neurological complications were investigated retrospectively based on medical notes excluding primary symptoms of stroke Le. motor weakness, sensory disturbance and speech disorder. And risk factors of stroke such as D.M. or hypertension are excluded. Results : Medical complications are more frequent than neurological ones. Most frequent medical complication is dysuria(61%) and constipation(45%), fever(30%) and aspiration pneumonia(22%) are followed in order of frequency. In Neurological complication dysphagia(56%), the exacerbation of infarction due to increased intracranial pressure(24%), irritability or insomnia(21%) is most frequently complicated in order of frequency. Conclusions : These complications are mostly caused by bed rest state in acute stage stroke. It is supposed that more aggressive management can prevent theses ones. And it is possible to improve the medical and neurological conditions by sticking theses study results.

• Tribology and Lubricants
• /
• 제31권1호
• /
• pp.6-12
• /
• 2015

This paper investigates the stick-slip characteristic of magnetorheological elastomer (MRE) between an aluminum plate and the surface of the MRE. MRE is a smart material and it can change its mechanical behavior with the interior iron particles under the influence of an applied magnetic field. Stick-slip is a movement of two surfaces relative to each other that proceeds as a series of jerks caused by alternate sticking from friction and sliding when the friction is overcome by an applied force. This special tribology phenomenon can lead to unnecessary wear, vibration, noise, and reduced service life of work piece. The stick-slip phenomenon is avoided as far as possible in the field of mechanical engineering. As this phenomenon is a function of material property, applied load, and velocity, it can be controlled using the characteristics of MRE. MRE as a soft smart material, whose mechanical properties such as modulus and stiffness can be changed via the strength of an external magnetic field, has been widely studied as a prospective replacement for general rubber in the mechanical domain. In this study, friction force is measured under different loads, speed, and magnetic field strength. From the test results, it is confirmed that the stick-slip phenomenon can be minimized under optimum conditions and can be applied in various mechanical components.

• 한국의상디자인학회지
• /
• 제9권2호
• /
• pp.31-48
• /
• 2007

The purpose of the this study is to make a historical review of changes in the structural decorations of men's costume from ancient times to modern times and to provide basic materials for developing handicraft decoration techniques and sewing methods in contemporary fashion. Their gorgeousness of collars and sleeves reached its peak along with the exaggerated expression of the human body during the Renaissance when people were free from Christian traditions of the Middle Ages and pursued human pleasures. Huge and decorative collars gave great dignity and formality to the wearer. Sleeves were slim and cuffs were small or nonexistent after the French Revolution. Various decorated pockets had been developed since pockets began to be attached to coats in the 17th century. Pockets were at the bottom of coat in the late 17th century, but they were gradually placed much higher on the coat. Buttons began to be used as the tool for sticking fast body to clothes in the 12th century and became extremely sumptuous accessories in the $16th{\sim}18th$ centuries. Men's clothes were simpler and more practical after the French Revolution. The result was that decorative buttons begun to disappear and metal buttons came out for practical purpose. The number of buttons worn on sleeves was also noticeably reduced. This research suggested the possibility that various decoration techniques could create the unique details in the each part of clothes. In order to develop high value-added products, we need to study various decoration-sewing methods and put to practical use them for creative fashion design.

• 한국한의학연구원논문집
• /
• 제12권3호통권18호
• /
• pp.31-47
• /
• 2006

Nowadays Korean governments use Information Technology to improve the quality of life for a people. One of these tries is building the Food Tracing System based on Information Technology. Koreans have big concern about food that is good for health. The Food Tracing System means that the system can follows, traces, and records every steps of production and delivery of food and its ingredient. And this process should be identified and grouped by using tags, marks, and other methods. For example, producer of ingredient, processing steps of food, delivered place could be traced. In addition to food, medical herbs need consumer's trust in production and delivery. To trace and prosecute contaminated medical herbs, medical herbs also need this kind of Tracing System based on Information Technology. This study shows current medical herbs tracing ways and RFID(Radio Frequency IDentification) technology trend. As preceding study for future RFID based medical herbs tracing system, this study suggests the building plan and scenario of the Medical Herbs Tracing System. The determination of the main body for sticking RFID Tags is very important to design for RFID Traceability System. In this study, the starting point of information to medical herbs is an inspection agency. The Medical Herbs to product domestically or import moved to an inspection agency. An inspection agency bond the RFID Tags to packing of the Medical Herbs after examining the a basic its component. At the same time inspector give the information of production or importation to the Tags. This Tags are moved for logistical process to end point, the Korean medicine agency. The customer confirmed the traceability and certification information of the Medical Herbs. For success tracing of medical herbs, institutional support and close cooperation between related organizations is necessary besides good system design.