• The Korean Journal of Ceramics
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• 제5권1호
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• pp.19-24
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• 1999

The influences of TiB2 additions to the β-sialon on mechanical propeties and electrical discharge machinability were investigated. Samples were prepared by adding 15, 30 and 45 vol.% TiB2 particles as a second phase to a β-sialon matrix. The β-sialon-TiB2 composites were sintered by hot pressing in a nitrogen atmosphere at 1800℃ with pressure of 30 MPa. The fracture toughness of the composites was increased with TiB2 content except 45 vol.% TiB2 composite. The crack propagation and crack deflection were observed with a SEM for etched samples after vicker's indentation. The composites containing more than 30 vol.% TiB3 had resistivity lower than 10-3 Ω㎝. The electrical discharge machining (EDM) of composited was conducted with two kind of machines such as die-sinker and wire cutter. The machinability was evaluated with the cutting rate surface roughness after machining.

• Earthquakes and Structures
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• 제18권3호
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• pp.313-320
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• 2020

The usage of conventional tuned mass damper (TMD) was proved as an effective method for passive mitigating vortex-induced vibration (VIV) of a bridge deck. Although a variety of linear TMD systems have been so far utilized for vibration control of suspension bridges, a sensitive TMD mechanism to wind spectrum frequency is lacking. Here, we introduce a bistable tuned mass damper (BTMD) mechanism which has an exceptional sensitivity to a broadband input of vortex shedding velocity for suppressing VIV in suspension bridge deck. By use of the Monte Carlo simulation, performance of the nonlinear BTMD is shown to be more efficient than the conventional linear TMD under two different wind load excitations of harmonic (sinusoidal) and broadband input of vortex shedding. Consequently, an appropriate algorithm is proposed to optimize the design parameters of the nonlinear BTMD for Kap Shui Mun Bridge, and then the BTMD system is localized for the interior deck of the suspension bridge.

• 한국자원식물학회지
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• 제22권3호
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• pp.242-247
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• 2009

Randomly Amplified Polymorphic DNA (RAPD) was performed to define the genetic variation and relationships of Artemisia capillaris. Fifteen populations by the distributions and habitat were collected to conduct RAPD analysis. RAPD markers were observed mainly between 300bp and 1600bp. Total 72 scorable markers from 7 primers were applied to generate the genetic matrix, and 69 bands were polymorphic and only 3 bands were monomorphic. The genetic dissimilarity matrix by Nei's genetic distance (1972) and UPGMA phenogram were produced from the data matrix. Populations of Artemisia capillaris were clustered with high genetic affinities and cluster patterns were correlated with distributional patterns. Two big groups were clustered as southern area group and middle area group. The closest OTUs were GW2 and GG1 in middle area group, and GB1 from southern area group was clustered with OTUs in middle area group. RAPD data was useful to define the genetic variations and relationships of A. capillaris.

• Archives of Pharmacal Research
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• 제17권4호
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• pp.231-235
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• 1994

Fluorenecarboxaldehyde hydrazone 9FCH)was synthesized as a new fluorescent reagent for the determination of acidity. FCH had no fluorescence in itself, however, it strongly fluoresced under acidic conditions at excitation maximum of 392 nm and emission maximum of 447 nm, respectively. It showed good correlation with pH in the range from pH 0.60 to pH 3.60 in strong acids. As an application, the acidity of gastric juice in rats and humans was determined. In comparision with pH-metry, the acidity measured by the developed method showed generally increased values of about 0.7-1.3 unit and 0.8-1.2 unit in rats and humans, respectively. However, these results had statistically close correlation with those of pH-metry and the correlation coefficients were 0.887 in rats and humans between two methods.

• 한국철도학회논문집
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• 제3권3호
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• pp.139-146
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• 2000

Recently, many kinds of research have been actively developing for a standardization and information to the field of design, construction, supervision, maintenance and management on facilities. The establishment of standard classification system on tunnel facilities and inspection data is most important among the things to have a efficiently maintenance and management. This paper suggests standard classification system on tunnel facilities and inspection data, and, on the basis of that, code work with standard classification system and input work was practised. The purpose of this paper is to suggest a kind of statistics data and investigate a characteristics of inspection using statistic data on railway tunnel.

• 품질경영학회지
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• 제40권3호
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• pp.270-277
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• 2012

Purpose: In this paper, storage lifetime of delay system in the fuse of 81MM illuminating projectile is estimated. Methods: Accelerated degradation testings of tungsten delay system using both temperature and humidity stresses were performed, and then delay time increase of the systems were analyzed as degradation data based on distribution-based degradation processes. Results: The estimated storage lifetime of detonator is between 11.8 years and 17.6 years with each stress-life relationship. Conclusion: Comparing with field data, storage lifetime of 90% reliability is about 12 years.

• Journal of Oral Medicine and Pain
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• 제39권3호
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• pp.115-118
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• 2014

A 50-year-old female patient with severe unilateral pain in the right eye, head, and face accompanied by lacrimation and drooping of the right eye and rhinorrhea from the right nose, which developed immediately after extraction of the maxillary right first and second molars, was successfully treated with oral administration of sumatriptan and prednisolone, or verapamile. Although the clinical characteristics are similar to those reported in cluster headache except the temporal feature, the probable cluster headache, the hemicrania continua and the acute migraine headache should be included in the list of differential diagnoses.

• 한국한의학연구원논문집
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• 제2권1호
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• pp.496-505
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• 1996

In order to improve the qualities of boiling extract the availability of standard compounds was investigated in extract of Scutellariae Radix. The standard compounds used baicalin(1), baicalein(2), and wogonin(3). The availabilities were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography(HPLC) on $C_18$ column. The extract of RS-4(W/V=10g/100m1) showed the highest availabilities as 7.95% of baicalin(1), 1.04% of baicatein(2), and 0.31% of wogonin(3).

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (A)
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• pp.262-264
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• 2006

고화질의 VoD 서비스를 위한 차세대 인터넷 서버는 디스크 컨트룰러, 네트워크 어댑터와 메모리를 하나의 하드웨어에 집적한 네트워크 스토리지 카드를 기본으로 리눅스 환경에서 개발되었다. 본 시스템에서 제공하는 입출력 경로를 리눅스에서 사용되고 있는 EXT3 파일시스템과 호환이 되도록 설계하고 구현하였다. 본 파일시스템은 기존의 EXT3 파일시스템의 기능을 그대로 사용하면서 대용량의 고화질 멀티미디어 데이터를 고속으로 처리하고, 시스템의 자원을 최소로 사용하면서 VoD 서비스에서 요구하는 데이터 입출력 처리 성능을 제공한다. 본 논문에서는 차세대 인터넷 서버 환경에서 개발된 멀티미디어 파일시스템의 설계, 구현 내용과 성능을 기술한다.

• 한국임상수의학회지
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• 제3권1호
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• pp.255-263
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• 1986

The incidences of liver abscess, fatty liver and fascioliasis were 11.9%, 23.2％ and 36.0%, respectively in 211 Holstein cattle observed at the slaughter house. Blood chemical values of them were measured. The results were as follows : 1. Liver abscess group was significantly higher than normal group in the levels of SDH, AST, TP, globulin and fibrinogen, but it was significantly lower than normal group in the levels of albumin and A/G ratio (p<0.01). 2. Fatty liver group was significantly higher than normal group in the levels of SDH, AST, OCT, TP and globulin, but it was significantly lower than normal group in the levels of albumin and A/G ratio (p<0.01). 3. Fasciolisais group was significantly higher than normal group in the levels of AST. TP and globulin (p<0.01), but it was significantly lower than normal group in the levels of albumin and A/G ratio (p<0.01).