• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.5
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• pp.413-420
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• 2012

In this study, the Kernel integration scheme for 2D linear elastic direct boundary element method has been discussed on the basis of subparametric element. Usually, the isoparametric based boundary element uses same polynomial order in the both basis function and mapping function. On the other hand, the order of mapping function is lower than the order of basis function to define displacement field when the subparametric concept is used. While the logarithmic numerical integration is generally used to calculate Kernel integration as well as Cauchy principal value approach, new formulation has been derived to improve the accuracy of numerical solution by algebraic modification. The subparametric based direct boundary element has been applied to 2D elliptical partial differential equation, especially for plane stress/strain problems, to demonstrate whether the proposed algebraic expression for integration of singular Kernel function is robust and accurate. The problems including cantilever beam and square plate with a cutout have been tested since those are typical examples of simple connected and multi connected region cases. It is noted that the number of DOFs has been drastically reduced to keep same degree of accuracy in comparison with the conventional isoparametric based BEM. It is expected that the subparametric based BEM associated with singular Kernel function integration scheme may be extended to not only subparametric high order boundary element but also subparametric high order dual boundary element.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.2
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• pp.90-95
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• 2009

Sludge pre-treatment utilizing cavitation is one of the commercialized methods at present. Cavitation can be generated by two different methods, sonotrode and hydrodynamic principle, and there has been no direct comparison between the two methods. In this study, solubilization efficiency, changes in sludge size distribution, and the methane production potential after pre-treatment by the two methods were compared. The maximum solubilization efficiency per unit energy input with the two methods was similar, and was 302 mg ${\Delta}SCOD/g$ TS at the energy input of 0.18 kWh/L. Break-up of sludge flocs were dominant during the early period of pre-treatment, while cell disintegration continued through the pre-treatment with the increase in the number of particles with less than 1 ${\mu}m$. BMP test results indicated that the methane potential increased up to 24.3% without differences between the two pre-treatments, and the increase in methane potential did not proportional to energy input. Although the energy efficiency of the two methods was quite similar, hydrodynamic methods might be a better choice for field application considering the operation and maintenance cost, and its potential improvement in energy efficiency.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.382-391
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• 2002

This study is devoted to the problems of thermal and shrinkage stresses in order to avoid cracking at early ages. The early-age damage induced by volume change has great influence on the long-term structural performance of the concrete structures such as its durability and serviceability To solve this complex problem, the computer programs for analysis of thermal and shrinkage stresses were developed. In these procedures, numerous material models are needed and the realistic numerical models have been developed and validated by comparison with relevant experimental results in order to solve practical problems. A framework has been established for formulation of material models and analysis with 3-D finite element method. After the analysis of the temperature, moisture and degree of hydration field in hardening concrete structure, the stress development is determined by incremental structural formulation derived from the principle of virtual work. In this study, the stress development is related to thermal and shrinkage deformation, and resulting stress relaxation due to the effect of early-age creep. From the experimental and numerical results it is found that the early-age creep p)ays important role in evaluating the accurate stress state. The developed analysis program can be efficiently utilized as a useful tool to evaluate the thermal and shrinkage stresses and to find measures for avoiding detrimental cracking of concrete structures at early ages.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1307-1316
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• 2016

This study was to execute the random arrangement of total 120 heads (10 heads per treatment plot ${\times}$ 3 repeats ${\times}$ 4 treatment plots) for four breeds [Blue arakana commercial Fowl (BC), Yeonsan silky fowl (YS), Korean native fowl (KN), White leghorn fowl (WL)] with the initiation of laying hens at 32 weeks old in order to comparatively analyze egg quality and composition by sorts of laying hens. In case of evaluation of the quality of eggs, this study has shown that BC had higher degree of Haugh unit coefficient (82.82) and in case cholesterol content of eggs, BC had significantly low content as 317.55mg/100g, but YS had rather higher content as 381.30mg/100g. Furthermore, this study has found out that BC had significantly low Oleic acid (C18:1n9) and WL had higher Amino acid content by breeds than those of other breeds (p<0.05).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.803-810
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• 2013

The purpose of this research is to analyze the effect of shape of the inductive textile electrode on the non-contact heart activity sensing, based on the magnetic-induced conductivity principle. Four types of the inductive textile electrodes were determined according to the combinations of the two shape features. A fiber-metal hybrid-typed conductive thread was developed and applied to materialization of the textile electrodes by embroidery method. The heart activity was extracted through the textile electrode sewn on a T-shirt. The experiments were implemented to constantly measure the heart activity for 20 seconds, in each case of 5 healthy male subjects. The heart activity signals acquired in each type of the inductive textile electrode were analyzed, 1)by drawing a comparison of morphology with those of ECG signal (LeadII), and 2)by calculation of the normalized mean and standard deviation of magnitude of the heart activity signals. The analysis resulted that the relatively better quality of signals were acquired in the 'square' types in the matter of whole shape, while the better results were obtained in 'donut' types in the matter of center hole. Accordingly, the relatively best quality of signals was obtained in the case of 'Square-Donut' type of the inductive textile electrode.

• Journal of architectural history
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• v.16 no.2
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• pp.99-118
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• 2007

Kyedan(戒壇) is an altar to perform a rite of Buddhist Initiation which gives Precept to a Buddhist monk. Sometimes it is called the Place of Precept and Mandala by Sanskrit. In this study, the Sutra of the Tang(唐) Dosun(道宣) regarding First Kyedan of Jetavana-anathapindasyarama(祇園精舍), which was the first temple such as, Kyedandokyung(戒壇圖經), Kiwonsadokyung(祇洹寺圖經), Sabunyul(四分律) were analyzed to find out original form and layout. Ultimately, the study was intended to examine the spatial formation-principle by comparing with Kyedan Temple. The results of this study could be summarized as below. First. Except for Kyedan in Bakryensa, the height of lower stone plate of Buddhist Bell-Shaped Stupa of Korean Kyedan is higher than three storied Kyedan that described in Kyedandokyung. Second. Buddhist Bell-Shaped Stupa above Kyedan was presumed that embodied image of Bell Pedestal and symbolism of overturned-bowl were combined together, when Kyedandokyung and Kiwonsadokyung were referred. It could be examined by the existence of stone lantern. Third. In Korea, the rite of Buddhist initiation that gives Precept in Kyedan has been considered impossible. However, when the rite was conducted, there was a possibility to establish wood stair. It is because that the Buddhist Stupa of Silleuuksa(神勒寺) and Woljeongsa(月精寺), which reflected the image of Kyedan had stone stair. Fourth, The method to build Kyedan of Dosun divided into Large Region and Small Region was applied to the method to construct Stone terrace behind Jeongmyeolbogung(寂滅寶宮) like Tongdosa(通度寺) and complete Kyedan on the stone terrace. In other words, Jeongmyeolbogung became Kyedanwon(戒壇院) and Kyedan, itself became Small Region. The area of Stone terrace became Large Region and naturally, they constituted an Institution. Fifth, Korean Kyedan which is consist of Jeongmyeonlbogung and Kyedan is a Korean original composition principles of Kyedangaram(戒壇伽藍) that can satiate all the functions of Kyedan as a religious subject and the place of the rite of Buddhist initiation, as it had complex of Outdoor Kyedan, which was suggested by the sutra of Dosun and Institution of Kyedan.

• Journal of Elementary Mathematics Education in Korea
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• v.12 no.1
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• pp.79-100
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• 2008

Freudenthal has advocated the reinvention method. In that method, the pupils start with a meaningful context, not ready-made concepts, and invent informative method through which he could arrive at the formative concepts progressively. In many face the reinvention method is contrary to the traditional method. In traditional method, which was named as 'concretization method' by Freudenthal, the pupils start with ready-made concepts, and applicate this concepts to various instances through which he could arrive at the understanding progressively. Through analysis, it turns out that Korea's seventh elementary mathematics textbook is based on concretization method. In this thesis, first of all, I will reconstruct probability unit of seventh elementary textbook according to Freudenthal's reinvention method. Next, I will perform teaching experiment which is ruled by new lesson design. Lastly, I analysed the effects of teaching experiment. Through this study, I obtained the following results and suggestions. First, the reinvention method is effective on the teaching of probability concept and algorithm. Second, in comparison with current textbook strand, my strand which made probability concept go ahead and combinatorics concept let behind is not deficiency. Third, tree diagram is effective matrix which contribute to formalization of combinatorics calculation. Lastly, except for fraction, diverse representation of probability, for example percentage or informal ratio expression must be introduced in teaching process.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.432-461
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• 1995

The basic principles in the design of Class II amalgam cavity preparations have been modified but not changed in essence over the last 90 years. The early essential principle was "extension for prevention". Most of the modifications have served to reduce the extent of preparation and, thus, increase the conservation of sound tooth structure. A more recent concept relating to conservative Class II cavity preparations involves elimination of occlusal preparation if no carious lesion exists in this area. To evaluate the ideal ClassII cavity preparation design, if carious lesion exists only in the interproximal area, three cavity design conditions were studied: Rodda's conventional cavity, simple proximal box cavity and proximal box cavity with retention grooves. In this study, MO amalgam cavity was prepared on maxillary first premolar. Three dimensional finite element models were made by serial photographic method. Linear, eight and six-nodal, isoparametric brick elements were used for the three dimensional finite element model. The periodontal ligament and alveolar bone surrounding the tooth were excluded in these models. Three types model(B option, Gap option and R option model) were developed. B option model was assumed perfect bonding between the restoration and cavty wall. Gap option model(Gap distance: $2{\mu}m$) was assumed the possibility of play at the interface simulated the lack of real bonding between the amalgam and cavity wall (enamel and dentin). R option model was assumed non-connection between the restoration and cavty wall. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed the displacement, 1 and 2 direction normal stress and strain with FEM software ABAQUS Version 5.2 and hardware IRIS 4D/310 VGX Work-station. The results were as followed. 1. Rodda's cavity form model showed greater amount of displacement with other two models. 2. The stress and strain were increased on the distal marginal ridge and buccopulpal line angle in Rodda's cavity form model. 3. The stress and strain were increased on the central groove and a part of distal marginal ridge in simple proximal box model and proximal box model with retention grooves. 4. With Gap option, Rodda's cavity form model showed the greatest amount of the stress on distal marginal ridge followed by proximal box model with retention grooves and simple proximal box model in descending order. 5. With Gap option, simple proximal box model showed greater amount of stress on the central groove with proximal box model with retention grooves. 6. Retention grooves in the proximal box played the role of supporting the restorations opposing to loads.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.56-66
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• 2015

This study aims at developing a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were performed on one unreinforced beam-column specimen and two reinforced specimens with U-type precast wall panels. Seismic resistant test of anchored and welded steel plate connections manifested an average of 2.8 times increase in the maximum loading (average 591.8 kN) in comparison to unreinforced beam-column specimen. The maximum drift ratios were also shown between 1.4% and 2.7%. An analytical study was performed while assuming the RC column on the right side and the vertical element of the reinforced PC panel to behave in completely composite manner and the RC column on the left side and PC panel to behave in completely non-composite manner when loading was exerted from upper right end of RC frame of specimen to its left side. It was found with the assumptions that the overall flexural behavior in principle agreed with the experimental result.

• Journal of Korean Medical classics
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• v.20 no.3
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• pp.9-22
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• 2007

We got some conclusion like below. after comparison and consideration mainly with commentary of "Somun(素問)", "Uihakyimmun(醫學入門)"about pulses, reasons, symptoms, treatments of HaeYok. The name of Haeyok was appeared "Somun(素問)", "Youngchu(靈樞)" for the first time, and from then 'Treatment From Pulse' was promoted into details. About the Pulse of Haeyok, every doctor followed the 'chokmaekwansaek' mentioned in "Somun Pyoungingisanglon(素問 平人氣象論)". But the letter 'wan(緩)' in 'chokmaekwansaek' was translated not pulse but drooped skin in "SomunKumsok(素問今釋)". On the reasons of Haeyok, we can lot out in detail like next; (1) heat of liver and abdomen, lack of blood. (2) declining Gi, little blood, (3) declining and little Gi of spleen, (4) Lack of Gi and Blood, (5) weak kidney energy, (6) nutritional vacancy, (7) no energy circulation from hardened kidney, (8) exogenous disease on void kidney (9) both weak meridian of liver, kidney. And it can be divided broadly into two groups; weak liver and kidney, declining and little Gi of spleen. The symptoms of Haeyok is that patient feels cold, but really that is not cold, feels weak, really not weak, feels vigorous but not. So hardly be named. the members are exhausted, people get lazy, annoying, sick. and have no vitality. Treatments about this, some prescriptions are suggested such as Baekhaptang(白合湯) from "Naekyoungsupyoubanglon(內經拾遺方論)", Yishintang(利腎湯) from "Hwangjesomunsonmyoungbanglon(黃帝素問宣明方論)". In "Dongyanguihakdaesajon", there's some treatment according to some reason; when we are lazy and don't know where is sick, use Haryoungmansudan(遐齡萬壽丹) or Shinsongijedan(神仙旣濟丹), When it is from Liquor, use Galhwahaedokdan(葛花解毒丹), When from humidity use Gamichulbutang(加味朮附湯), from cold use Ganghwalchunghwatang(羌活沖和湯), and when it comes from instable menstruation, it will be good Gamisoyosan(加味逍遙散). And treatment principle from "Uihakyimmun(醫學入門)" is that "Circulate Gi and blood, be thin skin, prescribe exogenous disease over for void organs."