• Structural Engineering and Mechanics
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• 제57권4호
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• pp.703-716
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• 2016

In this paper, we have investigated shear horizontal wave propagation in a layered structure, consisting of granular macromorphic rock (Dionysos Marble) substrate underlying a viscoelastic layer of finite thickness. SH waves characteristics are affected by the material properties of both substrate and the coating. The effects of microstructural parameter "characteristic length" of the substrate, along with heterogeneity, internal friction and thickness of viscoelastic layer are studied on the dispersion curves. Dispersion equation for SH wave is derived. Real and damping phase velocities of SH waves are studied against dimensionless wave number, for different combinations of various parameters involved in the problem.

• The Korean Journal of Ecology
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• 제1권2호
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• pp.49-56
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• 1977

For the culture the population growth, shell length and spawning seasons of Gomphina veneriformis, and its environmental factors, were investigated at the Jeju coastal regions. from Feburuary, 1975 to March, 1976. The soil movements of the tidal flats where the clams inhabited were relatively rapid during the strong tidal actions. The rate of population growth were rapid from April to September, then became obsure. The relative growth equations of the shell height (SH) and the shell breadth (SB) against the shell length (SL) of the clams were as follows: Changhung : SH=0.751 SL + 0.685, SB=0.448 SL-0.630 Pyoson : SH-0.775 SL - 0.115, SB=0.464 SL-1.008 Hwhason : SH=0.794 SL - 0.923, SB=0.485 SL-1.155 Kwhagzee : SH=0.771 SL - 0.644, SB=0.455 SL-1.049 The meat weight increases of the clams were continued from March to late June, then it decreased sharply up to late August. The spawning of the clams seems to be late from June to Spetember in the regions studied.

• 영어어문교육
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• 제15권4호
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• pp.75-94
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• 2009

This study was designed to assess demotivation factors and compare the factor between two secondary school student groups. It furthermore examined how the factors related to students' L2 proficiency. A 31-item questionnaire was completed by 407 junior (JH) and senior high school (SH) students. Five factors were extracted through the principal axis factoring: Teachers' competence and teaching styles, Dissatisfaction with English classes and grading system, Difficulty of learning English, Lack of motivation and interest in learning English, and Inadequate learning contents. Although both JH and SH students did not perceive their English teacher as a strong attribution of demotivation, Difficulty of learning English and Dissatisfaction with English classes and grading system were the two strongest demotivating factors. When compared the overall mean scores of each factor between JH and SH groups, significant differences were found in all factors except Factor 4, with SH students reporting stronger demotivation. JH students attributed their demotivation to Difficulty of learning English, while SH students attributed that to Dissatisfaction with English classes and grading system. Both groups tended to attribute their demotivation to external forces. The study also showed that several demotivation factors related negatively to L2 proficiency.

• 한국재료학회지
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• 제26권8호
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• pp.449-453
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• 2016

$HA(hydroxyapatite)/{\beta}-TCP$ (tricalcium phosphate) biomaterial (BCP; biphasic calcium phosphate) is widely used as bone cement or scaffolds material due to its superior biocompatibility. Furthermore, $NH_4HCO_3$ as a space holder (SH) has been used to evaluate feasibility assessment of porous structured BCP as bone scaffolds. In this study, using a spark plasma sintering (SPS) process at 393K and 1373K under 20MPa load, porous $HA/{\beta}-TCP$ biomaterials were successfully fabricated using $HA/{\beta}-TCP$ powders with 10~30 wt% SH, TiH2 as a foaming agent, and MgO powder as a binder. The effect of SH content on the pore size and distribution of the BCP biomaterial was observed by scanning electron microscopy (SEM) and a microfocus X-ray computer tomography system (SMX-225CT). The microstructure observations revealed that the volume fraction of the pores increased with increasing SH content and that rough pores were successfully fabricated by adding SH. Accordingly, the cell viabilities of BCP biomaterials were improved with increasing SH content. And, good biological properties were shown after assessment using Hanks balanced salt solution (HBSS).

• Asian Pacific Journal of Cancer Prevention
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• 제15권24호
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• pp.10597-10601
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• 2015

Up-regulation of multidrug resistance-associated protein 1 (MRP1) is regarded as one of the main causes for multidrug resistance (MDR) of tumor cells, leading to failure of chemotherapy-based treatment for a multitude of cancers. However, whether silencing the overexpressed MRP1 is sufficient to reverse MDR has yet to be validated. This study demonstrated that RNAi-based knockdown of MRP1 reversed the increased efflux ability and MDR efficiently. Two different short haipin RNAs (shRNAs) targeting MRP1 were designed and inserted into pSilence-2.1-neo. The shRNA recombinant plasmids were transfected into cis-dichlorodiamineplatinum-resistant A549 lung (A549/DDP) cells, and then shRNA expressing cell clones were collected and maintained. Real time PCR and immunofluorescence staining for MRP1 revealed a high silent efficiency of these two shRNAs. Functionally, shRNA-expressing cells showed increased rhodamine 123 retention in A549/DDP cells, indicating reduced efflux ability of tumor cells in the absence of MRP1. Consistently, MRP1-silent cells exhibited decreased resistance to 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and DDP, suggesting reversal of MDR in these tumor cells. Specifically, MRP1 knockdown increased the DDP-induced apoptosis of A549/DDP cells by increased trapping of their cell cycling in the G2 stage. Taken together, this study demonstrated that RNAi-based silencing of MRP1 is sufficient to reverse MDR in tumor cells, shedding light on possible novel clinical treatment of cancers.

• 한국산학기술학회논문지
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• 제18권5호
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• pp.596-607
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• 2017

의학학술문헌에는 해부학적 조직이나 기관명이 종양, 질환 또는 감염 용어들과 서로 조합하여 사용되는 언어적 특성을 가지고 있다. 의학학술문헌을 검색할 때 데이터베이스가 제공하는 통제어휘도구인 Medical Subject Headings (MeSH)를 활용하면 합성어, 동의어, 그리고 관련어를 추가로 검색할 수 있어 검색효율이 높다. 본 연구에서는 위암(Stomach Neoplasms) 어휘군을 검색용 필터로 추가하는 방법과 동시출현용어의 거리를 측정하여 단어인접탐색 기법으로 검색효율성을 향상시키는 연구를 수행하였다. 검색용 MeSH에 추가할 어휘군을 결정하기 위해 실험데이터로 PubMed에서 중심주제어가 "Stomach Neoplasms"인 2007년~2016년 논문 8,625편을 내려 받아 논문제목으로부터 Stomach와 Neoplasms 관련 용어의 동시출현여부를 분석하였다. 검색효율성은 KoreaMed에서 검색되는 MEDLINE 학술지를 대상으로 "Stomach Neoplasms"가 MeSH로 색인되어 있는 277편으로 검증하였는데 MEDLINE MeSH, MeSH on Demand, 그리고 KoreaMed MeSH Indexer의 "Stomach Neoplasms" 색인어 추출여부와 검색용 필터로 어휘군을 적용했을 때, 그리고 동시출현 용어의 단어인접검색 기법을 적용했을 때 "Stomach Neoplasms"의 매칭여부를 비교하였다. 가장 출현빈도가 높은 용어는 "Gastric Cancer"로 2,780회 출현하였다. "Gastric Adenocarcinoma", "Gastric MALT Lymphoma" 등과 같이 "Stomach" 용어와 "Neoplasms" 관련 조직학적 용어가 조합된 경우는 7,376개(88.51%)였다. 동시출현 거리가 2단어인 용어는 "Stomach"와 "Neoplasms"의 합성어로 5,234개(70.95%)였다. 연구 결과 MeSH용어를 제외하고 973개의 용어를 후보어휘군으로 선정하였다. MEDLINE MeSH와 KoreaMed MeSH Indexer의 MeSH 매칭률은 209편(75.5%)이었는데 검색필터를 적용한 결과 263편(94.9%)으로, 동시출현 용어의 13단어 단어인접탐색 기법을 적용한 경우 268편(96.7%)으로 매칭률이 향상되었다. 본 연구를 통해 자연어 검색에 있어서 검색효율을 향상시키는 수단으로 검색용 시소러스를 사용하면 색인비용에 대한 부담이 적고, 통제어의 망라적 장점과 자연어가 가지는 용어의 특정성을 유지할 수 있음을 증명하였다. 또한 불리안 검색보다는 단어인접탐색 기법을 활용하면 정확률을 높일 수 있어 검색 효율성이 향상됨을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권2호
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• pp.723-736
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• 2014

This paper proposes a matching engine for a query-by-singing/humming (QbSH) system with polyphonic music files like MP3 files. The pitch sequences extracted from polyphonic recordings may be distorted. So we use chroma-scale representation, pre-processing, compensation, and asymmetric dynamic time warping to reduce the influence of the distortions. From the experiment with 28 hour music DB, the performance of our QbSH system based on polyphonic database is very promising in comparison with the published QbSH system based on monophonic database. It shows 0.725 in MRR(Mean Reciprocal Rank). Our matching engine can be used for the QbSH system based on MIDI DB also and that performance was verified by MIREX 2011.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.253-259
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• 2004

Some new topological indices based on the distance matrix and Randic connectivity (as graph invariants) are proposed. The calculation of these indices is simple and they have good discriminating ability toward alkanes. Incorporating the number of carbon atoms to one of the calculated indices gives a highly correlating topological index (Sh index) which found to correlate with selected physicochemical properties of wide range of alkanes, specially, their boiling points. Most of the investigated properties are well modeled (with $r^2$> 0.99) by the Sh index. Meanwhile, the resulting regressions were compared with the results based on the well-established Randic and newly reported Xu indices and, in most cases, better results were obtained by the Sh index. Moreover, multiple linear regression analysis of the alkane properties via calculated indices gives highly correlating models with low standard errors.

• 한국정밀공학회지
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• 제26권6호
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• pp.90-96
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• 2009

Ultrasonic method using SH(shear horizontal) wave has been developed to determine the surface damage in fatigued material. Fatigue damages based on propagation energy were analyzed by multi-regression analysis in interrupted fatigue test specimen including CrMoV and 12Cr alloy steel. From the test results, as the fatigue damage increased the propagation time of the launched waves increased and amplitude of wavelet decreased. Also, analysis for the waveform modulation showed a reliable estimation, with confidence limit of 97% for 12Cr steel and 95% for CrMoV steel, respectively. Therefore, It is thought that SH ultrasonic wave technique can be applied to determine fatigue damage of in-service component nondestructively.

• 대한의생명과학회지
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• 제14권2호
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• pp.97-103
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• 2008

This study was conducted to investigate the effect of an anti-inflammatory and analgesic action of the glucosamine HCl (Glucosamine) and SH-1 (Glucosamine + Oriental herbal composition combined group). Male sprague-Dawley rats $(200{\sim}250g)$ and ICR mice $(20{\sim}30g)$ were randomized and these experimental groups were divided into 4 groups. Two control group were given as negative control (saline) and positive control (Ibuprofen, 100 mg/kg) and two groups given as oral administration of Glucosamine (320 m/kg) and SH-1. Carrageenan induced paw edema test, hot plate method, croton oil induced granuloma, capillary permeability test and acetic acid writhing syndrome were also shown to be comparable in the SH-1 group to anti-inflammatory drug group such as positive control group (Ibuprofen). Although further studies should be performed to confirm the effects of SH-1, present results suggest that the combined administration of SH-1 have potential action in anti-inflammatory and analgesic action. It could be applicable for the improvement of arthritic symptoms as a new diet-supplement.