• Title/Summary/Keyword: joint test

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An Application of Dirichlet Mixture Model for Failure Time Density Estimation to Components of Naval Combat System (디리슈레 혼합모형을 이용한 함정 전투체계 부품의 고장시간 분포 추정)

  • Lee, Jinwhan;Kim, Jung Hun;Jung, BongJoo;Kim, Kyeongtaek
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.42 no.4
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    • pp.194-202
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    • 2019
  • Reliability analysis of the components frequently starts with the data that manufacturer provides. If enough failure data are collected from the field operations, the reliability should be recomputed and updated on the basis of the field failure data. However, when the failure time record for a component contains only a few observations, all statistical methodologies are limited. In this case, where the failure records for multiple number of identical components are available, a valid alternative is combining all the data from each component into one data set with enough sample size and utilizing the useful information in the censored data. The ROK Navy has been operating multiple Patrol Killer Guided missiles (PKGs) for several years. The Korea Multi-Function Control Console (KMFCC) is one of key components in PKG combat system. The maintenance record for the KMFCC contains less than ten failure observations and a censored datum. This paper proposes a Bayesian approach with a Dirichlet mixture model to estimate failure time density for KMFCC. Trends test for each component record indicated that null hypothesis, that failure occurrence is renewal process, is not rejected. Since the KMFCCs have been functioning under different operating environment, the failure time distribution may be a composition of a number of unknown distributions, i.e. a mixture distribution, rather than a single distribution. The Dirichlet mixture model was coded as probabilistic programming in Python using PyMC3. Then Markov Chain Monte Carlo (MCMC) sampling technique employed in PyMC3 probabilistically estimated the parameters' posterior distribution through the Dirichlet mixture model. The simulation results revealed that the mixture models provide superior fits to the combined data set over single models.

Studies on Evaluation for Long-Term Structural Performance of Pinus densiflora Sieb. et Zucc. (I) -Shear Creep and Mechano-Sorptive Behavior of Drift Pin Jointed Lumber-

  • Hong, Soon-Il;Park, Jun-Chul
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.5
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    • pp.11-18
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    • 2006
  • This study was carried out to evaluate the mechano-sorptive deflection of shear creep of drift pin jointed solid wood. Specimens were the solid wood of Pinus densiflora. The joint was composed with steel plate and drift pin, 85mm in length and 10mm in diameter. The creep tests were conducted under the constant loads in an variable environment. Five different shearing loads were applied parallel to the grain of specimens. The shearing loads applied were 170, 340, 510, 680 and 850 kgf. The stress levels were 10, 20, and 30, 40 and 50% of the bearing strength obtained from the tension-type lateral strength test. The creep tests for specimens were carried out for 10300 hours. A few general conclusions could be drawn from this study: The mechano-sorptive deflection (${\delta}$ ms) is defined as ${\delta}\;ms={\delta}\;t-({\delta}\;c+{\delta}\;sh)-{\delta}\;o$, where ${\delta}$ t is the total deflection, ${\delta}$ c is the pure creep, ${\delta}$ sh is shrinkage-swelling behavior, and ${\delta}$ o is the initial deflection. Changes of relative humidity may cause more severe creep deflection than those of constant humidity, especially during the drying process. The mechano-sorptive behaviors of specimens, except the effects of shrinkage and swelling, gradually increased with increasing time. The deflection is increased in desorption process and recovered in adsorption process. The deflections of drift pin jointed solid wood under different loads showed almost same tendency in all specimens. Although the creep deflection tendencies of each series are very similar, the specimens subjected to a large shearing load exhibit large creep deflections in the desorption process than do those to the small shearing load specimens.

A Review of Clinical Shoulder Assessment Scales (견관절의 임상적 평가도구에 관한 고찰)

  • Yang, Dong-Hoon;Kim, Kun-Hyung;Kim, Haeng-Beom;Choi, Yang-Sik;Park, Young-Bae
    • Journal of Acupuncture Research
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    • v.24 no.6
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    • pp.123-135
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    • 2007
  • Objectives : A number of instruments have been developed to measure the quality of life in patients with various shoulder disorders. Much progress has been made in this area, and currently an appropriate instrument exists for each shoulder state. The purpose of this study is to review the instruments that are currently in use for assessing the shoulder joint. Methods : A literature research was performed to choose appropriate scales for assessment of function and the disability of the shoulder. Theoretically based scales were selected for review. Therefore, 11 scales were reviewed. The status of scales involved in shoulder treatment of acupuncture throughout several countries was evaluated. Results : 11 scales: The American shoulder and elbow surgeons evaluation form(ASES), Constant Shoulder Score, The disabilities of the arm, shoulder and hand(DASH), Shoulder Disability Questionnaire (SDQ), The Shoulder Pain And Disability index(SPADI), The simple shoulder test(SST), Oxford Shoulder Questionnaire(OSQ), The Rotator Cuff quality-of-life Measure(RC-QoL), Western Ontario Shoulder Instability Index(WOSI), Western Ontario Osteoarthritis of the Shoulder Index(WOOS), Western Ontario Rotator Cuff Index(WORC), wereevaluated. Each measurement has its own composition and characteristics. Their validity, reliability, responsiveness and practical characteristics were already evaluated. We found 3 domestic and 10 overseas papers about shoulder treatments using acupuncture assessed with shoulder scales. Conclusions : In clinical research, the selection of the measurement scale should take account of the condition of disease, the patient's traits and the characteristics of the research. Moreover, appropriate scales, which havevalidity, reliability, responsiveness and practical characteristics, are needed to enhance the quality of research.

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Internal derangement as a predictor of provoked pain on mouth opening: A magnetic resonance imaging study

  • Koh, Kwang-Joon;Park, Ha-Na;Kim, Kyoung-A
    • Imaging Science in Dentistry
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    • v.47 no.4
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    • pp.219-226
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    • 2017
  • Purpose: This study investigated the relationship between pain and internal derangement in temporomandibular disorder(TMD) patients using magnetic resonance imaging (MRI). Materials and Methods: This study analyzed 356 TMD patients (712 temporomandibular joints [TMJs]). The inclusion criteria were the presence of spontaneous or provoked pain on one or both TMJs and having undergone MRI. The patients with provoked pain were divided into 3 groups: pain on palpation, pain on mouth opening, and pain on mastication. MRI was performed using a 1.5-T scanner. T1- and T2-weighted parasagittal and paracoronal images were obtained. According to the findings on the T1-weighted images, another 3 groups were created based on internal derangement: normal, disc displacement with reduction, and disc displacement without reduction. The MRI findings were independently interpreted by 2 experienced oral and maxillofacial radiologists at 2 different times. Statistical analysis was performed by the chi-square test using SPSS (version 12.0; SPSS Inc., Chicago, IL, USA). Results: Provoked pain on mouth opening was found to be correlated with internal derangement in TMD patients (P<.05). However, spontaneous pain and provoked pain on palpation or mastication were not associated with internal derangement(P>.05). Conclusion: These results suggest that internal derangement was a significant predictor of provoked pain on mouth opening.

Study of Insam-Buja-Tang (IBT) on MRL/MpJ-Faslpr lupus-prone mice (루푸스 동물 모델에서 인삼부자탕(人蔘附子湯)이 미치는 영향)

  • Kim, Kyoung-Shin;Moon, Sung-Sikm;Kim, Byoung-Soo;Kang, Jung-Soo
    • Journal of Haehwa Medicine
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    • v.20 no.1
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    • pp.11-23
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    • 2011
  • Systemic Lupus Erythematosus(SLE) is an autoimmune disease invading the skin, joint, kidney, intestinal membrane, neurosystem and other organs. SLE is an autoimmune disease characterized by immune dysregulation resulting in the production of antinuclear antibodies(ANA), generation of circulating immune complexes, and activation of the complement system. In Korean medicine, lupus can be classified as acute arthritis, reddish butterfly erythema, asthenic disease, edema and so on. The cause and procedure of the diseases are flourishing noxious heat, excessive fire due to deficiency of yin, blood stasis due to stagnation of qi, internal movement of the liver-wind, congenital deficiency, exhausted vital-qi, which are treated by clearing away heat and cooling the blood, nourshing yin and extinguishing fire, treating flatulence and activating blood circulation, nourishing the blood to expel wind, invigorating the liver and kidney, invigorating qi and replenishing the blood. To experimentally examine the influence of Insam-Buja-Tang (Ginseng & Aconiti Extract, IBT) on the outbreak and development of lupus, lupus induce MRL/MpJ-Faslpr lupus-prone mice model was used. As IBT was orally administrated to a lupus model mouse, various tests such as the weight, urine protein, renal function, Lymph cell test of the spleen, Cytokine expression, histopathological analysis of kideny were performed to see the influence on the kidney and whether it work effectively on the immune function. The main purpose of this study is to evaluate the effect of IBT on MRL/MpJ-Faslpr lupus-prone mice model. The effect of IBT on MRL/MpJ-Faslpr lupus-prone mice that can have autoimmune disease similar to SLE in human was evaluated after IBT per oral in the present study.

Effect of Reflow Number on Mechanical and Electrical Properties of Ball Grid Array (BGA) Solder Joints (BGA 솔더 접합부의 기계적.전기적 특성에 미치는 리플로우 횟수의 효과)

  • Koo, Ja-Myeong;Lee, Chang-Yong;Jung, Seung-Boo
    • Journal of the Microelectronics and Packaging Society
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    • v.14 no.4
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    • pp.71-77
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    • 2007
  • In this study, the mechanical and electrical properties of three different ball grid array (BGA) solder joints, consisting of Sn-37Pb, Sn-3.5Ag and Sn-3.5Ag-0.75Cu (all wt.%), with organic solderability preservative (OSP)-finished Cu pads were investigated as a function of reflow number. Based on scanning electron microscopy (SEM) analysis results, a continuous $Cu_6Sn5$, intermetallic compound (IMC) layer was formed at the solder/substrate interface, which grew with increasing reflow number. The ball shear testing results showed that the shear force peaked after 3 reflows (in case of Sn-Ag solder, 4 reflows), and then decreased with increasing reflow number. The electrical property of the joint gradually decreased with increasing reflow number.

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A Study of the Relation between Food Habits , Anthropometric and Clinical Data in a Health Promoting Elementary School in Changwon (창원시 건강증진 시범학교 일부 아동의 식습관 , 체격지수 , 혈액성상에 관한 연구)

  • Lee, Gap-Yeon;Ju, Jeong;Lee, Bu-Ok
    • Journal of the Korean Dietetic Association
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    • v.7 no.4
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    • pp.331-348
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    • 2001
  • The purpose of this study was to obtain basic data for nutrition education of the children in a health promoting elementry school. The data was collected by a questionaire of food habits, and anthropometric measurement and biochemical test in comparison with obesity index. The study subjects were boys and girls aged 10 to 12 years who participated in the “99 Children Nutrition Camp”. The average obesity index was 1.7$\pm$21.6% in boys and -11.4$\pm$12.6% in girls. After school, major leisure items were significnatly different by gender but both boys and girls played mainly computer game. In concern for body image and eating habits, girls had more concern and girls had attempted weight control more than boys. 80.2% of subjects had prejudice for special food, especially, all subjects in the severely underweight group had prejudice. But this tendency was significantly decreased with the increasing obesity index. The lowest preferency was for vegetables(64.4%). The tendency of prejudice of subjects was higher whose mother are thirties than those of subjects whose mother are in fourties. The serum GOT and GPT values were significantly higher in overweight and obese group than the other groups. The only serum T-chol was significantly higher in boys than in girls. The number of risk factors related to coronary heart disease(CHD) based on coresponding criteria of TG, T-chol, HDL-chol, and LDL-chol was not increased significantly with the degree of obesity index. The results indicated the need of nutritional management for the children. At a point of view, to educate children early who are able to change food habits and life-styles means to help heathy growth and to deliver up heathy adults. Active nutrition education for both children and mothers will be recommended with joint participation of nutritionists in community public health center and elementary school.

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Effect of Chronic Foot Disease to Bone Mineral Density of the Affected Lower Limb (만성 족부 질환이 환측 하지의 골밀도에 미치는 영향)

  • Chu, In-Tak;Yoo, Jong-Min;Kang, Min-Gu;Chung, Jin-Wha
    • Journal of Korean Foot and Ankle Society
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    • v.14 no.2
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    • pp.165-168
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    • 2010
  • Purpose: Pain or discomfort caused by foot diseases may lead to abnormal gait, resulting in decreased bone mineral density (BMD) of the affected lower limb. We analyzed the effect of foot affection to BMD and its clinical significance. Materials and Methods: Bilateral hip BMD was evaluated in 93 patients with unilateral chronic foot disease. To minimize statistical errors, we excluded patients with medical histories that had influence on BMD. Analysis was based on the results of BMD tests at the first visit. All patients denied past medical intervention for osteoporosis. The difference in density between bilateral limbs was determined by comparing BMDs of the neck, upper neck, trochanter and total area of hip. Results: Test results revealed the decrease of BMD in the lower limb with the affected foot, compared to the unaffected side. This decrease was significant in the area of the trochanter (p <0.05). There was no marked difference of BMD in relation with duration of affection, underlying disease or age. Pertaining the location of foot affection, the hindfoot group showed significant decrease in BMD compared to the forefoot group. The group with affection in bone and joint also showed a marked decrease in BMD compared to the soft tissue group (p <0.05). Conclusion: Pain and discomfort caused by chronic foot diseases can lead to a decrease in the BMD of the affected lower limb. This may increase the risk of complications such as osteoporotic fracture and muscular atrophy.

Effect and Safety of a Commercial diet-food(Pulmuone $Diet^{(R)}$) in normal health obese females (건강 비만성인에 있어서의 시판 다이어트 제품의 다이어트효과와 안전성에 대한 연구)

  • Shin, Hyun-Taek;Kweon, Hyuk-Myung;Kim, Soo-Bin;Kwang, Sin-Uk;Yu, Ik-Hyun
    • Korean Journal of Clinical Pharmacy
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    • v.5 no.2
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    • pp.51-60
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    • 1995
  • Obesity is defined as excessive storage of energy in the form of fat resulting in adverse effect on healthy and longevity. Some data have shown increased incidence of hypertension, diabetes, hypercholesterolemia in overweight individuals and other disorders such as joint disease, cancer have been also associated with obesity. Recently, various commercial diet programs have been introduced for weight reduction without scientific evaluation for clinical effect and safety. The diet program must be based on a sound and scientific rationale and also be safe and nutritionally adequate. Pulmuone $diet^{(R)}$ is a calorie-restricted commercial diet-food, which contains adequate nutritients. The efficacy and safety of Pulmuone diet were evaluated in 28 normal healthy obese females in a prospective study. Each volunteer was placed in 3-week diet program. To observe weight reduction effect, body weight, TSF and AMC were measured every week. To account for safety of this program, blood chemistry test, blood pressure and side effects were monitored every week. Mean body weight was reduced by 3.24kg following diet program, which is statistically significant(P < 0.05) and this weight reduction was related to reduction in fat weight and not muscle weight as shown by the results of TSF and AMC Blood chemistry was not influenced by this program, but blood pressure was significantly reduced following this program. Thought diet program was generally well tolerated in most volunteers, the most frequent side effects are constipation, dizzness and headache. In conclusion, Pulmuone $diet^{(R)}$ program seems to be safe and effective for weight reduction in normal healthy obese females.

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An Expremental Study on Connections Friction Test of Improvement for Coastal Environment Block (Coastal Environments 블록의 개발을 위한 연결부 마찰 실험)

  • Kim, Chun-Ho;Kim, Sang-Hoonq
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.49-52
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    • 2008
  • The plain and simple shape water front structure were designed and installed for wave protection and wave resistance. But the installation of these plain and simple structure cause deficiency of environmental affinity. Also the resonance phenomena from the reflective wave and shipwave of the harbor incident wave caused high tide and wave, consequently maintaining the tranquility of inside harbor, give difficulty for mooring the ship and loading-unloading, increase the possibility of ship collision at the quray wall and landing place To solve these problems, we develop the environmentally friendly wave dissipation block. And installation efficiency, stability of the blocks through experiment of C.E Block Joint.

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