• Journal of Wind Energy
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• v.13 no.4
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• pp.42-49
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• 2022

Today, the power capacity of a wind turbine and the size of a blade is increasing to capture more wind resources, reduce the number of wind turbines on a wind farm, and reduce the cost of energy. As the blade size becomes larger, attention is being paid to the structural integrity of the blade root connection due to the heavy gravitational load effect and increased aerodynamic loads on the large blade, which could cause catastrophic failure of the blade. Therefore, the secure bolted joint connection of the blade to the hub is very important. In this paper, attention was given to the stress concentration factor (SCF) at the first thread between the M42 bolt and nut. The effect of various design parameters on the stress concentration factor was investigated, which included nut type, nut height, and reduced shank bolt. From a close design investigation of the numerical results, it turned out that the use of a reduced shank bolt resulted in the largest reduction of the stress concentration factor by 40 %, and the round nut type also reduced the SCF by 10 %, which will be beneficial to large wind turbine blades over 100 meters.

• 대한핵의학회:학술대회논문집
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• 1999.05a
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• pp.196-199
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• 1999

Radiation synovetomy with various radiopharmaceuticals has been used to alleviate pain and swelling of rheumatoid arthritis and related joint diseases for more than 40 years. It is an attractive alternative to the surgical synovectomy for the management of the various joint diseases. Recently, the development of new radiopharmaceuticals labeled with $^{90}Y,\;^{32}P,\;^{186}Re,\;^{188}Re,\;^{153}Sm,\;^{165}Dy$ and $^{166}Ho$, for the effective management of synovial inflammation and related arthritic problems are gaining attention. In this article the general concepts and the clinical application of radiation synovectomy are reviewed.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.128-135
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• 2006

Rational dynamic modeling and analysis method f3r complex structures are studied with special attention to slide way joints. For modeling of slide way joints, a general modeling technique is used by using the influence coefficients method which is applied to the conversion of detailed finite element model to the equivalent reduced joint model. The theoretical part of this method is illustrated and the method is applied to the structure with slide way joint. In this method, the non-linearity of the contact surfaces is considered within a proper range and the boundary effect of the joint model could be eliminated. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam and slide way joints of the vertical type lathe. The method can also be used to other kinds of joint modeling. The results of these analysis were compared with those of Yoshimura models and rigid joint models, which demonstrated the practical applicability of the proposed method.

• The Korean Journal of Pain
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• v.12 no.2
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• pp.231-234
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• 1999

Until several years ago we didn't think seriously about cervical problems as a cause of headaches, but since the publication of articles by Bogduk et al they have gotten more attention. Cervical headaches are associated with movement abnormalities of the structures of the neck such as cervical nerve roots, discs, joints and soft tissues. Considering this, we thought that the atlanto-axial joint could be one of the causes of these headaches. Headaches originating from this joint can be recognized by the fact that the pain worsens with rotation of the head in the horizontal plane. Pain can also be referred to the frontal area or around the orbit. We did atlanto-axial joint blocks using a posterior approach on 10 patients who suffered from this type of headache. The results were promising with 9 out of 10 patients showing more than 50% improvement on the numeric rating scale. There were no serious complications observed. We concluded that the atlanto-axial joint block can be an effective procedure in treating this specific type of headache.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.39.1-39.1
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• 2011

Due to less turbulence and no land limitation, offshore wind energy gets more attention than onshore. Jacket structure is regarded as a suitable solution for the water depth ranging from 30 to 80 meters. In general, joint stress concentration of jacket support structures affects their fatigue life. Nowadays, most jacket structures for offshore wind turbines have tubular X-joint between legs. In this paper, a study on X-joint stress concentration of offshore wind turbine jacket structure is performed by using 50m water depth model. Stress of X-joint on offshore environmental conditions are discussed.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.669-680
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• 2005

It is very difficult to determine the failure block scale in great rock slopes. Especially, postulating entire slope domain as a failure block without attention to discontinuity trace lenth makes very confuse and difficult to design rock slopes. In this paper, we estimate realistic failure block scale using joint system simulation method and introduce the application procedures on rock slope analysis. Besides, presenting how joint characteristics measurement and statistical analysis results are applicated to slope stability analysis design flow.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.79-84
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• 2002

The bottom-leaded plastic(BLP) packages have attracted substantial attention since its appearance in the electronic industry. Since the solder materials have relatively low creep resistance and are susceptible to low cycle fatigue, the life of the solder joints under the thermal loading is a critical issue for the reliability The represent study established a finite element model for the analysis of the solder joint reliability under thermal cyclic loading. An elasto-plastic constitutive relation was adopted for solder materials in the modeling and analysis. A 28-pin BLP assembly is modeled to investigate the effects of various epoxy molding compound, leadframe materials on solder joint reliability. The fatigue life of solder joint is estimated by the modified Coffin-Hanson equation. The two coefficients in the equation are also determined. A new design for lead is also evaluated by using finite element analysis. Parametric studies have been conducted to investigate the dependence of solder joint fatigue life on various package materials.

• Korean Journal of Cognitive Science
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• v.14 no.4
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• pp.43-51
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• 2003

The present paper is concerned with assessing both communicational skills and grammatical knowledge in three Korean-speaking children with a range in age from 9;11 to 12;2 and in MLU from 1.68 to 2.22. It was found that all three autistic children's speech was largely repetitive and echolalic, unable to consistently interact communicatively on the ongoing joint focus of attention. It was also observed that the more repetitive the child speech was, the more impaired morpho-syntactically it was. Based on these findings, it was speculated that the deficit in joint focus of attention might relate to grammatical development.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.145-147
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• 2014

공동주의는 사회적 개체간의 지각적 경험을 공유하는 상호작용과정으로, 최근 인간-로봇 상호작용연구와 관련해서 로봇 공학자의 관심이 커지고 있다. 발달심리학에 기초한 기존의 developmental robotics의 접근과는 달리, 본 연구에서는 사전단서 패러다임을 이용해서 목표물, 단서, 주의반응 간의 삼자관계를 수학적으로 개념화하였다. 간단한 목표물 탐사과제를 통해서 계산모형의 수행을 검증하였다. 연구결과에서는 컴퓨터 시스템의 시각적 주의 모형이 사용자가 지시하는 단서(손가락 지시)의해 목표물(이온음료)을 주의를 할당하는 것을 보였다. 본 연구는 심리학에서 연구된 사전단서 패러다임을 인간-로봇 상호작용에 적용될 수 있음을 보여준다.

• Asian Journal of Business Environment
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• v.8 no.1
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• pp.7-15
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• 2018

Purpose -This paper is to study the process of the negative effects of Sino-foreign joint ventures, hoping to find out an effective path in which local enterprises can avoid the risks in the utilization of foreign capital, and ultimately achieve independent innovation. Research design, data, and methodology -The outflow of assets, the loss of local brands and the "technology hollowing-out" problem brought by joint ventures is becoming more and more serious. Based on conflict analysis graph model, this paper takes Yuhuan joint venture as an example to identify the conflict problem in Sino-foreign joint ventures. Results -The results of the stability analysis show that establishing joint venture cannot really realize the introduction of technology because the technology is fully controlled by the foreign part. So when introducing foreign capital, local enterprises should participate in R&D and master the initiative. Conclusions - Local enterprises should pay attention to patent containment and technology blockade of multinationals. Domestic enterprises should try to protect state-owned assets and local brands in Sino-foreign joint ventures. Independent innovation is the most effective strategy for the development of enterprises in China.