• Laser Solutions
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• v.13 no.3
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• pp.1-6
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• 2010

The in-process monitoring of $CO_2$ welding of Zn-coated steel plates has been studied and compared with that of conventional thin plates. Relationships between weld defects and plasma emission signals were evaluated in laser lap joint of thick Zn-coated steel. According to the study, weld defects were found to increase with Zn content. As a result, measured plasma emission signals also decreased. In case of plate with $15{\mu}m$-thick Zn-coated layer, defects caused by evaporation of Zn could, therfore, controled by gap of 0.1mm, resulting in a stable emission signals. However, the amplitude of signals fluctuated very widely. Variation of amplitude sould be limited in 3-8V by FFT smoothing.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.361-365
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• 2002

Advancements in silicon phase control (SCR) technologies provide an arc welding power supply that has the capability to allow the alteration of the Alternating Current (AC) welding output. These technologies provide a square wave output involving sixteen frequency selections and multiple balance selections. While an AC out put is known to minimize magnetic disturbances associate with Direct Current (DC), the potentials of a non-sinusoidal waveform have not been explored. The focus of the paper is to determine the effects that the frequency and balance of an AC wave form output will have upon a high speed Submerge Arc (SAW) application. The test matrix of the project includes welding .250" steel plate. Joint type is square groove with a travel speed of 65 IPM. Each of the weld parameters was held constant, only the frequency and/or balance were altered between welds. Each frequency/balance combination involved three-gap spacing. Upon completion of the welds the bead profiles were measured and recorded. A relationships/trends were observed with various frequency and balance values. Optimum frequency and balance values were found for the .250" square groove application which permit consistent weld sizing, ease of slag removal, and minimal plate distortion.

• Journal of Welding and Joining
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• v.13 no.4
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• pp.122-131
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• 1995

An automatic welding equipment for thick plates requires the capability of the seam tracking of the weld line which often includes misalignment of the workpiece and variation of groove width. In this study, an automatic welding equipment and control algorithms based on the arc sensor were proposed for the GMA welding of thick plates which had misalignment and gap variation. The developed system being constituted with 5 axis can be automatically controlled by computer and also automnatically set the welding conditions such as welding current, and voltage. The proposed algorithms for the seam tracking in multi-pass welding of the thick plates were constituted as follows : the detection of weaving-end point for findng the variation of groove width, the control of welding velocity for acquiring a constant thickness deposition of weld metal, and the calculation of groove width and height of an arbitrary pass in the multi-pass weld. As results of the application of the system, it was revealed that the system had a good capability in seam tracking and made an excellent weld quality in V groove butt joint.

• The Korean Society of Law and Medicine
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• v.12 no.2
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• pp.189-217
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• 2011

According to the current law of national health insurance, the Minister of Health and Welfare can impose a suspension of business or license, and a fine with medical institutions who violate the law. In case that medical institutions raise an action for ity with each penalty, they ask for replacing the suspension of business with a fine during the pendency of the action. But there is a long gap of time between an offense and administrative measures. One violation cause several types of administrative measures (suspension of business or fine, suspension of license etc.) and different government departments impose these penalties. It takes a lot of time to organize their opinions and they are liable to impose penalties after considerable space of time because of overwhelming tasks. Then the medical institutions can sustain a loss by getting unexpected administrative measures after their offense against the law. Thus, this article review whether extinctive prescription apply to the right of imposing fine on the law of national health insurance or not. Meanwhile, we have no regulations imposing a same fine to co-representatives of medical institution who infringe the law of national health insurance. On this point, this study review whether they have equal duty on that or not.

• Archives of Plastic Surgery
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• v.33 no.3
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• pp.379-382
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• 2006

Clinodactyly is defined as an angulation of a digit in the radio-ulnar plane. This anomaly can be congenital, dominantly inherited, or acquired due to trauma or inflammation. Although the deformity usually causes little functional impairment, correction is made because of cosmetic problems. Male subject, with polydactyly on thumb(Wassel's type VII) received first surgery at the age of one. And at the age of six, abnormal growth on the radial side of the first metacarpal bone and ulnar deviation of the distal phalanx of the thumb at the interphalangeal joint had developed. The authors used the growing bony segment from the first metacarpal bone as a bone graft for the correction of clinodactyly on thumb. Z-plasty incision was made on the concave(ulnar) side of thumb and a wedge osteotomy was made on the distal phalanx. The bone graft was inserted into the gap of the distal phalanx of the thumb and fixed it with K-wires. Deformity of the metacarpal bone and clinodactyly on thumb was corrected effectively without donor site morbidity with noticible growth of the grafted metacarpal bone 12 months after surgery.

• Korean Journal of Organic Agriculture
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• v.28 no.1
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• pp.69-93
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• 2020

The paper is to compare two villages in Songak-myeon, Asan, Cnungnam Province in Korea. It tries to show how the joint village project, which began with the support of the same external organization, produces different results depending on the internal conditions and circumstances of the village. From the end of the 1990s, Pyeongchon-ri and Sugok-ri started developing villages under the influence of the environmentally friendly farming movement. And subsequent supports were provided by local organizations for the development of the village. However, the village project in Sugok-ri, which focused on economic performance, later turned out to be a failure, and the residents changed to pursue activities for their own economic interests individually. On the other hand, In Pyeongchon-ri, the cooperation among villagers was strengthened in implementing support projects by similar external agencies. In addition, community ties and identity have been strengthened as problems have been solved through cooperation among residents in the process of promoting the village project. Nevertheless, projects undertaken in Pyeongchon-ri for the purpose of increasing economic performance was all failed. Through these findings, the paper asserts that the neo-endogenous development approach utilizing external support on the basis of internal cooperative network among villagers must be a very useful method for rural development in contemporary societies.

• Economic and Environmental Geology
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• v.35 no.4
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• pp.373-378
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• 2002

Among the science and engineering fields in North Korean Academy of Sciences, geology occupies about 10 percent of the total number of departments. An analysis of major geologic research fields in North Korea, based on the number of authors of 2000-200l publications in a representative journal "Geology and Geography", shows the proportions as follows: mineralogy and petrology (31.0%), stratigraphy and paleontology (12.3%), economic geology and geochemistry (11.6%), geophysics and structural geology (14.2%), and applied geology (31.0%). This proportion is similar to that in South Korea in 1960s and shows that geologic research activity in North Korea is concentrated for the purpose of mineral resources exploration. The academic collaboration between South and North Korea in near future should include the researches on the reconstruction of geologic history in Korean peninsula and Northeast Asia and the environmental restoration from mining-related environmental pollution in North Korea. For active academic interchange between South and North Korea, efforts to overcome the academic gap are requisite. Frequent joint symposia, interchange programme of post-doctoral fellows, and cooperative researches on specific topics are recommended for this effort.

• Nuclear Engineering and Technology
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• v.46 no.5
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• pp.595-604
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• 2014

SILER (Seismic-Initiated event risk mitigation in LEad-cooled Reactors) is a Collaborative Project, partially funded by the European Commission in the $7^{th}$ Framework Programme, aimed at studying the risk associated to seismic-initiated events in Generation IV Heavy Liquid Metal reactors, and developing adequate protection measures. The project started in October 2011, and will run for a duration of three years. The attention of SILER is focused on the evaluation of the effects of earthquakes, with particular regards to beyond-design seismic events, and to the identification of mitigation strategies, acting both on structures and components design. Special efforts are devoted to the development of seismic isolation devices and related interface components. Two reference designs, at the state of development available at the beginning of the project and coming from the $6^{th}$ Framework Programme, have been considered: ELSY (European Lead Fast Reactor) for the Lead Fast Reactors (LFR), and MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) for the Accelerator-Driven Systems (ADS). This paper describes the main activities and results obtained so far, paying particular attention to the development of seismic isolators, and the interface components which must be installed between the isolated reactor building and the non-isolated parts of the plant, such as the pipe expansion joints and the joint-cover of the seismic gap.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.353-361
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• 1989

A parametric study of load distribution in bolt-nut joints is performed by the method of finite element contact analysis. The contacting surface is assumed unbonded and frictionless. Multi-body contact analysis is performed in elastic region under the assumption of axi-symmetric stress state. Load acting on the first thread from the fastened plate is much greater than that on the other threads in the standard setting. But the load distribution is shown to be improved by making the center of contact force acting on the nut surface move outwards. Such a modification is possible by enlarging the gap between bolt shank and fastened plate or by inserting suitable washers. Shape modification of the standard nut by the making a groove and a step on the nut surface is also suggested, which results in almost uniform load distribution and considerable decrease in the maximum stress of the joint.

• Journal of Welding and Joining
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• v.17 no.2
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• pp.66-75
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• 1999

Weld bead quality in tailored blank(TB) is critically affected by edge preparation of sheets. The edge quality of prepared sheets for TB can be classified into straightness and the cross section quality of sheared plane such as a ratio of shear face, shear plane angle, etc. In order to have a good edg quality for butt-welding sheets, precision shearing will be recommended. In this paper, the feasibility of a conventional mechanical shearing as the edge preparation for tailored blanks is studyied. It reveals that fine shearing may not be the unique solution as it is generally accepted. To obtain the good shearing condition with a conventional mechanical shearing, experiments were carried out using Tahuchi method. The major parameters affecting a sheared contour are the clearance between upper blade and lower blade, and shear angle. The optimal shearing condition yields a very good straightness along the entire length of the cut, which gives a butt joint gap less than 10% of the base material thickness. The good cross section of sheared plane is also achieved in the optimal shearing condition such as a ratio of the shear face above 65%, a cross section's shear plane angle above 85%, little burr, which is providing finally good weld beads.