• 한국문화재보존과학회:학술대회논문집
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• 2002.02a
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• pp.21-31
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• 2002

Lime-soil consolidations are very important as structural material, bonding material, waterproofing material, and finishing material in korea traditional buildings. In this study, we investigated site application trouble in korea traditional buildings being repaired or restored, and propose following solutions. 1) To diminish quality variation occurred by slaking quick-lime in site, it is desirable to use slaked-lime for lime-soil consolidation. 2) For uniform construction of lime-soil consolidation, we would recommend builders to use mixer to be uniform mixture, premixed type materials and compacting machine in field, 3) and to use rigid suitable temporary construction as scaffold for preventing traditional buildings from additional damage occurred in demolition and construction of a layer of lime-soil consolidation of a roofing. 4) For suitable repair of traditional buildings, it is necessary to specify definitely materials and construction methods suggested by the standard specifications for repair of the cultural property.

• Journal of Conservation Science
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• v.12 no.1 s.15
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• pp.15-25
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• 2003

It is well known that the salt in stoneworks impact on damage of stone by various methods. Various kind of salt is detected in high content in the black surface layer of stone monuments and it is required about origin and roles of salts on blackening to considerate. In this study have been investigated the characteristics of salt in the black crust of sandstone and limestone which used in historical monuments in Berlin, Germany. Salt was analyzed for cation by Atomic Absorption and Atomic Emission Spectroscopy and for anion by ion Chromatograph. The representative ions are $Ca^{2+}\;and\;SO_4^{-2}$ in all samples and the most obvious combinations was proved in calcium sulfate by statistical methods. Because gypsum was detected by X-ray diffraction analyses in the black crusts, this calcium sulfate was confirmed by 2 hydrate type. The probable origin of Ca is air particle in atmosphere around sandstone and calcite in mother rock in limestone, and that of S is polluted air and mortar which used as conservation works.

• Journal of Conservation Science
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• v.32 no.1
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• pp.51-61
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• 2016

'Eojin', king's portraits, had been produced during the Joseon dynasty. The portrait of King Taejo, the founder of the Joseon dynasty, remain at National Palace Museum of Korea and Gyeonggijeon portrait hall in Jeonju and Junwonjeon portrait hall in North Korea that has been recorded in original glass plate photo in 1911. Many replica of Eojin have been made since it is important to preserve and protect original one. In this study, the portrait of King Taejo, which is possessed by National Palace Museum of Korea, was researched for making replication standard version of the original form. It was focused on derivations of each artefacts and drawing lines those had been described on the picture including comparison among three portraits of King Taejo. Producing the replication standard version of King Taejo's portrait, the digital restoration techniques by the method of partition area scanning was applied. Accurate and precise detail result that is taken by digital imaging technique gives additional information regarding the relations among three portraits of King Taejo.

• Journal of Conservation Science
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• v.33 no.1
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• pp.17-24
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• 2017

Studies were conducted on manufacturing techniques by applying microscopy and conservation treatments on the annals of Joseon dynasty storage box at the National Museum of Korea. The results revealed that lime tree wood(Tilla spp.) was used to make the annals of Joseon dynasty storage box. Lacquering techniques were used to coat the box with a layer of lacquer and bone ash and then cover it with traditional Korean paper. After being covered with traditional Korean paper, more layers were applied in the following sequence: mud ashes, black lacquer, pure lacquer, and black lacquer. Before conservation treatments, some components and lacquer layers were missing in addition wood joint were loose. Therefore, conservation and restoration should be conducted based on the identified wood and by observing the shape of the remaining components.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1691-1696
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• 2010

The efforts of reflecting the system's uncertainties in design step have been made and robust optimization or reliabilitybased design optimization are examples of the most famous methodologies. The statistical moments of a performance function and the constraints corresponding to probability conditions are involved in the formulation of these methodologies. Therefore, it is essential to effectively and accurately calculate them. The sensitivities of these methodologies have to be determined when nonlinear programming is utilized during the optimization process. The sensitivity of statistical moments and probability constraints is expressed in the integral form and limited to the normal random variable; we aim to expand the sensitivity formulation to nonnormal variables. Additional functional calculation will not be required when statistical moments and failure or satisfaction probabilities are already obtained at a design point. On the other hand, the accuracy of the sensitivity results could be worse than that of the moments because the target function is expressed as a product of the performance function and the explicit functions derived from probability density functions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.721-725
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• 2007

A fiber optic based weight sensor has fabricated using a fiber Bragg grating with a weight sensitive. The sensing concept exploits the inherent characteristics of the FBG and is based on the strain effect induced in the fiber Bragg grating through. A direct indication of the weight level is given by the shift of the Bragg wavelength caused by the expansion of the sensing material. A FBG behaves like a spectral filter which has inherent characteristics that render it very sensitive to strain and temperature. The sensing principle is also based on the strain effect induced in the FBG through the caused by the weight. The experimental setup used for the initial investigation to characterize the mass response of the sensor. The transmitted signal from the sensor was monitored using an optical spectrum analyzer with a resolution bandwidth of 0.4nm. In this paper, we presented the spectral characterization and shaping of FBG by scanning a mass element that affects a small grating fraction at a time, without permanent effects on the optical fiber when the various wavelength and strain is removed. That is, destruction when the optical fiber for weight is physically damaged.

• Explosives and Blasting
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• v.40 no.4
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• pp.1-14
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• 2022

To review the appropriateness of current regulations on the simple explosive storage facility, the effects of internal explosion on the structural stability of the standard storage facility were analyzed by means of both FEM analyses and field experiments. As a result, it was found that the explosion-proof performance of the existing storage structure was not sufficient for 15 kg of emulsion-type explosive. Thus, an alternative method of splitting explosives was tested by conducting sympathetic detonation experiments. This method worked properly as expected, and the proper amount of splitted explosive was determined according to the test results. In addition, a storage structure with open ceiling was found to be very effective because explosion pressure was released so rapidly that the damage of the facility could be reduced significantly. Hence, such a structural pattern was proposed as a new design scheme for simple explosive storage facility.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5A
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• pp.873-880
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• 2006

PSC composite bridge with precast decks which was designed by the proposed horizontal shear equation was fabricated. Fatigue test was performed to evaluate the endurance of shear connection and the behavior of PSC composite bridge. After all the fatigue loading were applied, no crack and no residual slip were occurred. The flexural stiffness of PSC composite bridge was maintained the initial value, and demage of shear connection was not occurred. To verify the applicability of horizontal shear equation and shear connection detail and to evaluate the strength of PSC composite bridges, static test was also executed. PSC composite bridges with precast decks had 2.08 safety factor which was the ratio of crack to serviceability load and showed ductile behavior after ultimate load. Test results showed that the proposed design equation of the shear connection gave reasonable horizontal shear connection design. Fast and easy construction would be achieved using the suggested precast system.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.250-250
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• 2022

호안은 유수로부터 제방과 하안을 보호하는 구조물로 태풍 또는 집중호우로 인한 홍수로부터의 안정성이 확보되어야 한다. 일반적으로 호안공법은 강성호안과 연성호안으로 구분되는데 호안재료로써의 기준과 설치 및 유지상태 기준에 따라 다르게 해석되고 있는 것이 현실이다. 최근에는 호안공법의 재료의 연결성에 따라 강성호안과 연성호안을 구분짓는다고 언급되기도 한다. 본 연구에서는 친환경 석재를 사용하고 재료와 기반재의 체결을 통해 연결성을 확보하고 굴요성을 갖게 하는 연성호안공법에 대해 실규모 실험을 계획하였다. 수리 안정성 검토를 위한 실규모 실험은 안동 하천실험센터에서 수행하였다. 실험에 사용된 수로는 8°의 경사를 갖는 급경사수로에서 수행하였으며, 수로의 제원은 폭 3m, 길이 30m 의 직사각형 형태의 직선수로로 이루어져 있다. 시험체는 실규모로 제작되며 실험수로 내 2m × 10m 의 제원을 갖는 공간에 제작된 호안공을 크레인을 이용하여 실험수로에 설치하였다. 수리 안정성 실험은 실험대상유량을 단계별로 나누어 점차적으로 증가시키고, 시험체의 이탈, 파괴 등의 큰 변화가 발생(미국 재료시험학회 연결형 콘크리트 블록 시험방법, ASTM D 7277)하였을 경우 실험을 종료하도록 계획하였다. 수리량 측정항목은 유속, 수위 등이 있으며, 호안공 의 물리적 변화는 3D스캐너를 이용하여 설치 전·후 변위를 검토하였다. 총 3회에 걸쳐 실험을 수행하였으며 실험조건에 따라 일부 시험체에서 돌출 또는 침하현상이 발생하기도 하였으나 호안의 손상이나 이탈, 연성기반재의 찢어짐 등 안정정을 저해하는 호안공 시험체의 변화는 발생하지 않는 것으로 확인되었다. 실험결과 실험수로에서 발생가능한 최대유량인 4.6cms 조건에서 본 호안공법은 약 337.7N/m² 의 소류력을 확보하는 것으로 확인되었다.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.2
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• pp.80-88
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• 1997

Malignant tumors of extremeties involving major neurovascular structures have been treated by amputation. However recent development of diagnostic tools(CT, MRI etc.), surgical techniques, anticancer chemotherapeutic agents, and radiation techniques allow surgeons to treat malignant tumors in the limb without amputation. It has been reported that a local application of low-heat to the tissue with tumor can kill tumor cells. It is, however, not known if the attendant neural and vascular injuries may be recovered. The present study was, therefore, undertakn to address this question in rabbit sciatic nerves. A low-heat injury to the sciatic nerve was induced by perfusing the nerve with $60^{\circ}C$ saline for 30 minutes and the courses of functional and morphological recovery of the nerve were evaluated for 16 weeks. The results are summerized as follows : 1. In the electromyographic nerve conduction test the average amplitude was markedly attenuated at 4 and 8 weeks after the low-heat treatment, but it progressively increased to the level 89.5% of the control at 16 week post-treatment. The average latency in the control group was 0.62 msec. The latency in the experimental group was much longer than this at 4 and 8 week post-treatment, but it progressively reverted to the control level, showing 0.622 msec at 16 weeks. 2. In the needle EMG, many fibrillation potentials and positive sharp waves were appeared until 8 weeks post-treatment. After 16 weeks, however, no fibrillation potential was observed. 3. In the early phase of post-treatment period, the myelinated nerve fibers contained many vacuoles and the number of myelinated nerve fibers appeared to be considerably reduced. However, as time goes myelinated nerve fibers were regenerated, such that after 16 weeks the histologic appearance of the nerve was similar to that of the control group.