• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1672-1677
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• 2005

The Heat exchanger to be used in the place of business that is presented an utility period comes to be long and the problem of the length of life shares by the manufacture course and using environment factor. Consequentl, it is came to the front problem of inspection, repair, exchange, the utility stopping, safety and confidence. As a result the possibility which the large safety accident can happen comes to be high. It leads mostly to the large accedent when the explosion accident happens. to keep this, The system which the regular period passes to disuse the structure is prepared but The phenomenon which Time and the strength characteristic of the material change, namely Deradation. but It can't be a preventable solution by accident to the damage. Consequentl, This research can take important role to prevent an every kind accident for domestic pressure vessel by evaluating the mechnical characteristic change of meterial, the structure safety and residual life etc.

• Journal of Dental Rehabilitation and Applied Science
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• v.21 no.2
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• pp.191-204
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• 2005

Traditionally, the implant treatment require load-free healing period of at least 3 months in the mandible and 6 months in the maxilla. But this long healing period provides patients with the discomfort and economical trouble. Many experiments has been attempted for the outcome of such disadvantage, so recently the immediate loaded implant is getting popularity. Several literature has been published for clinical success of immediate loaded implant. The studies for the success rate of immediate loaded implant in multi-way has been reporting, nevertheless, we don't have yet a probable success. Various studies have been practiced that the advantages and disadvantages associated with immediate loaded implant, and factors that may influence the success of immediate implant, including patient selection, type of bone quality, required implant length, structure of the implant, surgical skill, need for achieving primary stability, control of occlusal force, peri-implant bone activity. The objective of this study is to review the literature related to immediate loading of implants and to discuss factors that may influence this treatment modality, based on scientific evidence.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1479-1484
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• 2011

The existing leg-rest for transmission line construction was established on the ground as a structure. As a result of that, it caused some problems such as, a tremendous forest damage, excessive construction costs and the long time of construction period. In order to solve these problems, we suggest the protective net for an air installation. It is a new method of construction which has a dielectric strength with a light-weight and high-strength. And it's not influenced by a geographical feature. This excellent method doesn't affect a forest and can reduce tremendously the construction cost and period.

• The Journal of the Korean dental association
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• v.54 no.6
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• pp.438-446
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• 2016

Severe tooth wear may cause the pathologic change of the TMJ and masticatory muscles, unesthetic facial appearance, pathogenic pulp and occlusal disharmony. Treating patients with severely worn dentition often requires full mouth rehabilitation with increasing vertical dimension. Proper diagnosis and treatment planning are important for esthetic and functional definitive restorations and the long term stability of the neuromuscular system and the TMJ. In this case, 66 year-old female presented with generalized worn dentition. Based on assessment, pathologic destruction of teeth structure on entire dentition was caused by masticatory force and diet habit without loss of vertical dimension. Subsequently, 3 mm increase of vertical dimension that based on incisor for tooth restoration and esthetic improvement was determined. After 8 weeks stabilization period with temporary fixed prostheses, definitive prostheses were fabricated. After 6 months follow up period, satisfactory outcomes were attained both functional and esthetic aspects through this procedure.

• International Commerce and Information Review
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• v.10 no.1
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• pp.295-314
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• 2008

I compared trade structure and competitiveness by sector using industrial classification in UN Comtrade data and SITC. Based on the comparison, I calculated market share, export competitions, RCA, and TSI. and then selected sensitive industries based on competitiveness, and identified the ZOPA and our BATNA. These calculations confirmed the industries damaged by FTA and those benefiting from the FTA between Korea and Japan, the study them developed strategies for VIA negotiation. It is to minimize damages to Korean economy and to maximize benefits from the agreement. The negotiation plan allowed an adjustment period for industries, for which damages are expected, by setting a long grace period before implementing tariffs. Based on the negotiation plan made through economic analysis, I intend. contribute to more efficient promotion of negotiation by extracting the optimal FFA negotiation plan for each manufacturing industry.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.30-34
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• 2007

Structural integrity of railway vehicles should last for a long period against various and continuous fatigue loadings, and the carbody structures of railway vehicle are manufactured by applying multiform welding types for each material. Since the most of cracks are occurred and proceeded at the vicinity of welding area during the lifetime of carbody structure, the fatigue strength evaluation for welding area of carbody structure should have been carried out. Rotem Company has evaluated lifetime and fatigue strength of carbody structure according to the fatigue analysis based on the international standard and/or inner-official regulation. This study introduces the fatigue analysis method that we have evaluated and calculated the damages for the welding areas of carbody structure under various fatigue loading conditions using cumulative fatigue damage rule(Miner's rule) to verify whether the cumulative damage does exceed unity. This study contains the fatigue test of specimens to derive stress-life relations(S-N curve), sub-modeling analysis and the calculation of cumulative damages under fatigue loading. The fatigue analysis verifies the welding area shall be capable of withstanding under fatigue loading, identifies how critical area shall be selected and presents the principles to be used for design verification.

• East Asian Economic Review
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• v.21 no.3
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• pp.201-230
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• 2017

This paper studies the long-run behavior of relative price dispersion among cities in Korea with a special emphasis on heterogeneous transitional patterns of price level dynamics. Formal statistical tests indicate considerable evidence for rejecting the null of relative price level convergence among the majority of cities over the sample period of 1985-2015. The analysis of gravity model suggests that the effect of transportation costs on intercity price level differentials is limited, while other socioeconomic factors, such as income, input factor prices, demographic structure, and housing price growth, play key roles in accounting for persistent regional price level disparities. Individual price levels are found to be better explained by a multiple-component model, and the deviations from PPP may be attributed to distinct stochastic common trends that are characterized by income and demographic structure.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.993-998
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• 2011

In this paper we suggest new criteria for the classification of the electrode gap between common and scan electrodes. The electrode gap is categorized as a short, middle, and long gap according to the criteria. Among these structures, we focus on the erase waveform of a mid-gap structure. we report an unstable discharge arising from the erase ramp period in a mid-gap structure. Based on the Vt close curve, we analyze the unstable discharge at various conditions. Our analysis reveals that the unstable discharge is ignited between surface electrodes and caused by un-erased wall charges accumulated on the outer edges of electrodes. By reducing the voltage level of the last sustain pulse, the problem is solved.

• Smart Structures and Systems
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• v.14 no.3
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• pp.367-376
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• 2014

Ambient vibration techniques are nowadays a very popular tool to assess dynamic properties of buildings. Due to its non destructive character, this method is particularly valuable, especially for health monitoring of historical monuments. The present ambient vibration experiment consists on the evaluation of vibration modes of a Medieval tower. Situated in Soncino (close to Cremona, in the Northern Italian region named Lombardia), the tower of 41.5 meters height has been monitored by seismometers located at different points inside the structure. Spectral ratios of the recorded ambient vibrations clearly identify a fundamental mode at about 1 Hz, with a slight difference in the two horizontal components. A second mode is also evidenced at approx 4-5 Hz, with a moderate degree of uncertainty. The records of a ML 4.4 earthquake, occurred during the monitoring period, confirm the information obtained by microtremor analysis. Daily variations of both 1st and 2nd mode were detected: these variations, of an amount up to 2%, seem to be well related with the temperature.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.185-192
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• 2005

Using existing static methods, it is possible to estimate accurately the reponses of structures governed by the fundamental mode. However, these methods do not provide reliable estimates for the structure where higher mode effects are significant. Parametric study was performed to analyze the dynamic characteristics of the structure with long vibration period. Based on the investigations, a new modal combination method using modal combination coefficients, Factored Modal Combination, was developed, and static earthquake load patterns addressing higher mode effects reasonably were proposed. Existing modal combination methods, such as SRSS and CQC, lack a theoretical basis to be applied to inelastic structures. In contrast, the proposed method can be applied conveniently in inelastic range as well as in elastic range.