• 한국정밀공학회지
• /
• 제29권10호
• /
• pp.1078-1088
• /
• 2012

In this paper, we present research experimental results about the different thickness T-joint welding of the high power continuous wave(CW) Nd:YAG laser for the secondary battery of a vehicle. Although the conventional method used for the secondary battery is a argon TIG welding, we utilize a laser welding to improve Tungsten Inert Gas(TIG) welding's weakness. The laser, which has a couple of advantage such as aspect ratio, low Heat Affected Zone(HAZ), good welding quality and fast productivity utilized in this work is a CW Nd:YAG laser. In order to observe laser welding sections, we used a optical microscope. Through the analysis of the metallographic, hardness, aspect ratio, and heat input, we obtained the desired data in condition of 1800 W laser beam power and 1.8 m/min and 2.0 m/min laser beam travel speeds. In order to compare electric resistances of the argon TIG welding and laser welding, we made an actual battery and the electric resistance of the laser welding is reduced by 40~45% comparing with the argon TIG welding.

• 한국콘텐츠학회논문지
• /
• 제14권9호
• /
• pp.582-588
• /
• 2014

본 연구는 국가간 공동연구 네트워크가 기술 지식의 확산에 어떠한 영향을 미치는 가와 네트워크 상에서 중심성이 높은 국가가 새로운 기술을 얼마나 받아들이는지 분석하고 그 의미를 찾는 것을 목적으로 한다. 이를 위해 이차전지 분야와 전기 자동차 분야 논문 정보를 이용하여 연도별 국가간 공동연구 네트워크 밀도와 참여국가 수를 측정하고 변수간의 회귀분석을 수행하였다. 분석결과, 이차전지 분야 공동연구 네트워크 밀도가 증가할수록 참여국가 수는 선형관계로 증가하는 것으로 나타났다. 또한 공동연구 네트워크 상에서 연결정도 중심성이 높은 국가들이 중대형 이차전지 분야 개발을 주도하고 있는 것으로 나타났다. 반면에 전기 자동차 분야의 경우, 네트워크 밀도값은 증가 추세가 나타나지 않지만, 참여국가 수는 증가하고 있는 것으로 나타났다. 이는 기술 확산을 촉진하는데 있어서, 국가간 공동연구가 중요한 역할을 하지만 필요충분 조건은 아닌 것으로 분석되었다. 이러한 결과는 기술 성장에 있어서 반드시 필요한 기술 확산을 촉진하는 요인을 통계적으로 검증하였다는 점에서 의의가 있으나, 네트워크 상에서 중심적 역할에 대한 지표를 연결정도 중심성 만으로 측정하였다는 점과 네트워크 밀도가 행위자간 상호작용에 있어서 반드시 두 행위자간 관계만을 측정한다는 점에서 연구의 한계가 존재한다. 따라서 향후 다수의 연구자간 상호작용을 측정할 수 있는 방안에 대한 연구가 필요하다.

• Earthquakes and Structures
• /
• 제22권3호
• /
• pp.231-243
• /
• 2022

Beam-column joints (BCJs) are recognized among the most crucial zones in reinforced concrete structures, as they are the critical elements subjected to a complex state of forces during a severe earthquake. Under such conditions, BCJs exhibit behaviors with impacts that extend to the whole structure and significantly influence its ductility and capability of dissipating energy. The focus of this paper is to investigate the effect of undamaged transverse beam (secondary beams) on the ductility of concrete BCJs reinforced with conventional steel and shape memory alloys bars using pushover analysis at tip of beam under different axial load levels at the column using a nonlinear finite element model in ABAQUS environment. A numerical model of a BCJ was constructed and the analysis outcomes were verified by comparing them to those obtained from previous experiments found in the literature. The comparison evidenced the capability of the calibrated model to predict the load capacity response of the joint. Results proved the ability of undamaged secondary beams to provide a noticeable improvement to the ductility of reinforced concrete joints, with a very negligible loss in load capacity. However, the effect of secondary beams can become less significant if the beams are damaged due to seismic effects. In addition, the axial load was found to significantly enhance the performance of BCJs, where the increase in axial load magnified the capacity of the joint. However, higher values of axial load resulted in greater initial stiffness of the BCJ.

• The Korean Journal of Pain
• /
• 제7권2호
• /
• pp.292-298
• /
• 1994

The common disorder called facet syndrome exhibits lower back pain, with or without, radiating pain to buttock and thigh due to facet joint arthropathy. Many physicians have believed that the usual lesion of facet syndrome was an anatomical impairments of facet joint itself. So facet joint block has been known only as a therapeutic and diagnostic modality of facet syndrome. Based on clinical experience and anatomical study, we have concluded varying opinions from common sense about facet syndrome. Pain in the facet joint is supposedly the secondary effect of narrowing of joint space by sustained muscle contracture around joints. We therefore conclude that spasmolytic treatment of muscles connecting the two vertebral articular space would be better for treatment and diagnosis of facet syndrome rather than facet block with local anesthetic and steroid only.

• BMB Reports
• /
• 제40권2호
• /
• pp.232-238
• /
• 2007

The p13 gene is uniquely present in Group II nucleopolyhedroviruses (NPVs) and some granuloviruses, but not in Group I NPVs. p13 gene was first described by our laboratory in Leucania separatamultiple nuclear polyhedrosis virus (Ls-p13) in 1995. However, the functions of Ls-P13 and of its homologues are unknown. When Ls-p13 was inserted into Autographa californica nucleopolyhedrovirus, a Group I NPV, polyhedra yield was inhibited. However, this inhibition was prevented when the leucine zipper-like domain of Ls-p13 was mutated. To determine the cause of this marked difference between Ls-P13 and leucine zipper mutated Ls-P13 (Ls-P13mL), oligomerization and secondary structure analyses were performed. High performance liquid chromatography and yeast two-hybrid assays indicated that neither Ls-P13 nor Ls-P13mL could form oligomers. Informatics and circular dichroism spectropolarimetry results further indicated marked secondary structural differences between Ls-P13 and Ls-P13mL. The LZLD of Ls-P13 has two extended heptad repeat units which form a hydrophobic surface, but it is short of a third hydrophobic heptad repeat unit for oligomerization. However, the mutated LZLD of Ls-P13mL lacks the above hydrophobic surface, and its secondary structure is markedly different. This difference in its secondary structure may explain why Ls-P13mL is unable to inhibit polyhedra yield.

• Journal of Korean Neurosurgical Society
• /
• 제54권4호
• /
• pp.366-369
• /
• 2013

Lumbar microdiscectomy (MD) is the gold standard for treatment of lumbar disc herniation. Generally, the surgeon attempts to protect the facet joint in hopes of avoiding postoperative pain/instability and secondary degenerative arthropathy. We believe that preserving the facet joint is especially important in young patients, owing to their life expectancy and activity. However, preserving the facet joint is not easy during lumbar MD. We propose several technical tips (superolateral extension of conventional laminotomy, oblique drilling for laminotomy, and additional foraminotomy) for facet joint preservation during lumbar MD.

• Clinical and Experimental Pediatrics
• /
• 제56권7호
• /
• pp.291-297
• /
• 2013

Purpose: The aim of this study was to investigate prophylactic treatment effects in Korean patients with severe hemophilia A. Methods: A prospective study of 32 severe hemophilia A patients was conducted with the approval of the Institutional Review Board at the Eulji University Hospital. Two patients received primary prophylaxis; whereas, the other 30 patients were divided into 2 groups-secondary prophylaxis (n=15) and on-demand (n=15)-on the basis of their consent for secondary prophylaxis. A 20-25 IU/kg dose of factor VIII concentrate was administered to the primary and secondary prophylaxis group patients every 3 days for 1 year. The prophylactic effect was evaluated by observing changes in the Pettersson scores, annual number of total and joint bleeds, and factor VIII consumption for 1 year. Results: No moderate or severe bleeding was observed, and the Pettersson scores remained unchanged during the prophylaxis period in the patients who received primary prophylactic treatment. After the treatment was changed from on-demand to secondary prophylaxis, the annual number of total and joint bleeds in the secondary prophylaxis group decreased by $64.4%{\pm}13.0%$ and $70.0%{\pm}15.2%$, respectively. The average increase in Pettersson scores within 1 year was $0.5{\pm}0.8$ and $1.3{\pm}1.1$ in the secondary prophylaxis and on-demand groups, respectively. Prophylactic effects were also observed in patients >17 years who had nearly the same initial Pettersson scores. Conclusion: Intermediate-dose prophylactic treatment may delay hemarthropathy progression and prevent its occurrence in Korean severe hemophilia A patients.

• 근관절건강학회지
• /
• 제23권3호
• /
• pp.152-158
• /
• 2016

Purpose:The purpose of this study was to examine the degree of joint pain, limitation of daily activities, and frequency of outpatient visits. Methods: This secondary analysis study used the data from the fifth Korean National Health and Nutrition Examination Survey (KNHNES). The data about general characteristics, prevalence and treatment of osteoarthritis, limitation of activities of daily living (ADL) and frequency of outpatient visits and hospitalization in 424 osteoarthritis patients over 50 years old were derived from the database. Data were analyzed with complex samples in SPSS ver. 20.0. Results: Among people with knee joint pain, 79.3% reported they had more than 4 out of 10 points of the degree of pain. Meanwhile, 97.3% of people with hip joint pain reported that they had more than 4 out of 10 points of the degree of pain. People reporting 10 out of 10 point of pain were 21.4% of those with knee joint pain and 25% of those with hip joint pain. The mean of the degree of knee joint pain was 6.35, and the mean of the degree of hip joint pain was 6.89 out of 10 points. About 50% of people with osteoarthritis visited an outpatient clinic within the last 2 weeks, and 27% had limitation of ADL. Conclusion: It is necessary to develop an integrated intervention program to improve quality of life in patients with osteoarthritis.

• The Korean Journal of Pain
• /
• 제30권1호
• /
• pp.59-61
• /
• 2017

We report a case of fluoroscopy-guided intraarticular steroid injection for sternoclavicular joint (SCJ) arthritis caused by limited cutaneous systemic sclerosis (SSc). A 50-year-old woman diagnosed with limited cutaneous SSc presented with swelling and pain in the right SCJ. MRI revealed signs of inflammation consistent with right-sided sternoclavicular joint arthritis. After the failure of oral medications, we performed fluoroscopy-guided injection in this region. She reported complete resolution of her symptoms at 4 and 12-week follow-ups. This outcome suggests that a fluoroscopy-guided SCJ injection might be a safe and successful treatment option for sternoclavicular joint arthritis.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(D)
• /
• pp.297-299
• /
• 2012

In this paper, we introduce a joint flow control and scheduling algorithm for multi-hop cognitive radio networks with spectrum underlay. Our proposed algorithm maximizes the total utility of secondary users while stabilizing the cognitive radio network and still satisfies the total interference from secondary users to primary network is less than an accepted level. Based on Lyapunov optimization technique, we show that our scheme is arbitrarily close to the optimal.