• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.31-39
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• 2010

The goal of automatic velocity analysis is to extract accurate velocity from voluminous seismic data with efficiency. In this study, we developed an efficient automatic velocity analysis algorithm by using bootstrapped differential semblance (BDS) and Monte Carlo inversion. To estimate more accurate results from automatic velocity analysis, the algorithm we have developed uses BDS, which provides a higher velocity resolution than conventional semblance, as a coherency estimator. In addition, our proposed automatic velocity analysis module is performed with a conditional initial velocity determination step that leads to enhanced efficiency in running time of the module. A new optional root mean square (RMS) velocity constraint, which prevents picking false peaks, is used. The developed automatic velocity analysis module was tested on a synthetic dataset and a marine field dataset from the East Sea, Korea. The stacked sections made using velocity results from our algorithm showed coherent events and improved the quality of the normal moveout-correction result. Moreover, since our algorithm finds interval velocity ($\nu_{int}$) first with interval velocity constraints and then calculates a RMS velocity function from the interval velocity, we can estimate geologically reasonable interval velocities. Boundaries of interval velocities also match well with reflection events in the common midpoint stacked sections.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.77-87
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• 2010

Hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) has been an increasing problem worldwide since the initial reports over 40 years ago. To examine new drug leads with potential antibacterial activities, Various N'-[(-3-substituted-4-oxo-1,3-thiazolidin-2-ylidene]-4-hydroxy benzohydrazide (4a-4.i) and N'-[-(3,4-disubstituted)-1,3-thiazolidin-2ylidene)]-4-hydroxybenzohydrazide from (5.a-5.i) to (10.a-10.i) were synthesized using appropriate synthetic route. The entire test compounds (4.a-4.i) and from (5.a-5.i) to (10.a-10.i) were assayed in vitro against s. aureus strain. The minimum inhibitory concentration (MIC) was determined for test compounds and for reference standards. The test compounds showed significant antibacterial activity against the strains used, when tested in vitro. In general, p-hydroxybenzohydrazide ring and substituted thiazoline ring are essential for antimicrobial activity. Among the compounds tested, compounds 6.f, 7.g, 9.f and 10.f, 10 i were found to be most potent. The test compounds were found nontoxic upto the dose level of 2000 ${\mu}g$/mL. The intact compounds were then subjected for 3D-QSAR studies. 3D-QSAR study based on the principal of alignment of pharmacophoric features by Schrodinger PHASE module. The 3D-QSAR study allowed us to confirm the preferential binding mode of p-hydroxybenzohydrazide inside the active site.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.366-376
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• 2017

This study attempts to analyze the structure of the knowledge and duties of the vocational counseling service industry by using the text mining method and network analysis, which are methods of big data analysis. The subjects of the survey were vocational counseling, job placement and career change support, three fields in the unit elements of competence included in the National Competency Standards (NCS) which areproposed by the government. Although the analysis results of frequently used words showed that all three fields had independent duties, many were overlapping, such as counseling, examination, employment support, etc. for clients, job seekers, and others. The knowledge required by the employees of this field includes many new fields, such as start-up development, lifelong career consulting, job adaptation and culture conflict, besides the five subjects of vocational psychology, vocational counseling, labor market, job information, and law, which are included in the vocational counselor certification examination. Also, we suggested that the consultants adhere to emotional approaches, such as empathy, acceptance and attentiveness, and take a neutral stance. This study isvaluable in that it is the first attempt to objectively analyze the duties of the vocational counseling service field by big data analysis. In addition, it is also meaningful that we first confirmed the difference between the direction of government policy and the actual practice in the field.

• The korean journal of orthodontics
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• v.37 no.4
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• pp.283-292
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• 2007

The purpose of this study was to evaluate the clinical usefulness of 4 self etching primers by measuring the shear bond strength of orthodontic brackets and examining the failure pattern of bracket-tooth interfaces. Methods: Seventy-five, defect-free, premolars were randomly assigned into five groups: control group (37% phosphoric acid + Transbond XT primer) and self etching primer treated groups (Transbond Plus self etching primer, Unifil bond, Clearfil SE bond, and Adhese). The shear bond strength was measured with a universal testing machine and the amount of residual adhesive remaining on the brackets after debonding was assessed by the adhesive remnant index (ARI). Results: The results showed that the groups conditioned with self etching primer had significantly lower shear bond strength than the control group (p < 0.05), although clinically acceptable. However, there were no significant differences in shear bond strength among the self etching primer groups (p > 0.05). Evaluation of the ARI scores indicated there was less resin remnant on the teeth in the groups conditioned with self etching primers, although not statistically significant. Conclusion: The results of this study suggest that all four of the self etching primers have shown acceptable bond strength for clinical use.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.413-419
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• 2002

본 연구의 목적은 품질경영시스템의 ISO 9000:2000/KS A 9000:2001 개정 규격 내용 및 요구사항을 살펴보는 한편, 우리나라 중소기업이 전환규격을 적용하는데 있어서 ERP PACKAGE를 이용하여 효과적인 품질경영시스템 구축 방안을 제시하기 위함이다. 본 연구에서는 업무 PROCESS와 품질 기록을 중심으로 ISO 9000:2000/KS A 9000:2001 개정 규격을 ERP PACKAGE에 접목하는 방법을 도출하였으며, 적용 사례로서 기계 제조업체의 구매업무를 중심으로 품질경영시스템 구축방안을 제시하였다. 본 연구의 결과는 다음과 같다. 첫째, 정형화된 업무 체계를 갖추어 업무 담당자간 혹은 부서간의 업무 마찰을 줄이고 여러부서에서 발생하는 업부 DATA를 중앙집중식으로 공유하여 동일한 DATA의 수집과 작성에 중복성을 최소화하는 등에서 업무의 효과가 있는 것을 볼 수 있다. 둘째, ERP PACKAGE를 이용한 품질경영시스템(ISO 9000:2000/KS A 9000:2001)의 효과적인 추진 방안은 다음과 같다 1) 전환 규격의 충분한 이해가 요구된다. 2) 현재의 업무 프로세스를 파악한 후 ERP PACKAGE에서 제공하는 개선된 업무프로세스를 적용하는 것이 필요하다. 3) 개선된 업무 프로세스의 실행 결과를 ERP PACKAGE 모듈에서 품질기록으로 유지한다. 4) 새로운 품질경영 정보 시스템을 업무 전반에 적용하기 위한 기업인프라 구축과 프로세스에 대한 지속적인 개선이 요구된다. 본 연구에서는 ISO 9000:2000/KS A 9000:2001 개정 규격요구사항을 이해하고 ERP PACKAGE를 이용하여 최초로 개정규격을 적용하거나, 전환규격으로 품질경영시스템을 구축 시 좀더 효과적이고 효율적인 품질경영시스템을 구축하는데 업무지침으로 활용될 수 있을 것이다.의 수와 생존율면에서 볼 때 가장 적합한 것으로 사료되었다./TEX>개월 투여하게 되면 HDL 콜레스테롤 양이 현저히 증가하였으며, 총 콜레스테롤 양, 동맥경화지표, 중성지방, 유리지방산, 과산화지방은 현 저히 감소하였다.- 결론 - 홍삼과 진세노사이드는 사람과 흰쥐에 있어 과지혈증을 호전시켰다. 실험적으로 과지혈증을 유발시킨 흰쥐에서, 혈중 아포단백질, 지방단백질 및 프로스타글란딘 상호성을 개선시켰다.었다.xA_{2}$ synthetase 억제제인 imidazole의 효과와 유사하였다. 4. G-Re는 $1{\times}10^{-5}g/ml$ 이하의 농도에서는 효과가 없으나 $1{\times}10^{-4}g/ml$ 이상의 농도에서 농도의존적으로 유의성 있는 $PGE_{2},\;PGF_{2}{\alpha},\;TXB_{2}$의 생성억제와 함께 6-keto-$PGF_{1}{\alpha}$ 증가를 보였다. 이는 prostacyclin synthetase를 자극하는 serotonin의 효과와 같은 작용으로서 prostacyclin synthetase 억제제인 tranylcypromine에 대하여 길항효과를 보였다. 5. $TxB_{2}$생성억제 작용을 나타내는 ginsenoside들의 효과를 뒷받침하기 위하여 인삼 saponin 성분을 전처치한 patelet rich plasma에서 혈소판 응집시험 결과, ADP로 유도된 혈소판 응집반응에는 모든 인삼 saponin 성분들이 효과가 없었으나 arachidonic acid로 유도된 혈소판 응집반응에는 $G-Rb_{2}$, G-Rc, G-Re의 순으로 농도 의존적인 억제현상을 보였다. 이상의 결과와 같이 인삼 saponin 성분들은

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.476-486
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• 2004

This paper is the second part of the study on the development of a smart active layer (SAL) sensor, which consists of two parts. As mentioned in the first paper, structural health monitoring (SHM) is a new technology that is being increasingly applied at the industrial field as a potential approach to improve cost and convenience of structural inspection. Recently, the development of smart sensor is very active for real application. This study has focused on preparation and application study of SAL sensor which is described with regard to the theory and concept of the SAL sensor in the first paper. In order to detect elastic wave, smart piezoelectric sensor, SAL, is fabricated by using a piezoelectric element, shielding layer and protection layer. This protection layer plays an important role in a patched network of distributed piezoelectric sensor and shielding treatment. Four types of SAL sensor are designed/prepared/tested, and these details will be discussed in the paper In this study, SAL sensor ran be feasibly applied to perform structural health monitoring and to detect damage sources which result in elastic waves.

• KSBB Journal
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• v.14 no.1
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• pp.114-118
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• 1999

In order to use a polysaccharide, curdlan, as a concrete admixture, we first developed a pilot-scale fermentation process for the mass production of curdlan. We also examined the rheological properties of curdlan, and tested how well the curdlan obtained in this work increased the segregational resistance of the cement slurry. Fermentation was performed in a 300-liter fermenter equipped with 3 disk-turbine impellers. Since curdlan production is stimulated under nitrogen-limiting conditions, the culture pH was shifted from the optimal pH for cell growth (pH 7.0) to the optimal pH for curdlan production (pH 5.5) at the onset of ammonium exhaustion. We obtained a curdlan production of 65 g/L in 120 hr batch cultivation of Agrobacterium species. The insoluble curdlan at the final stage of fermentation was readily harvested by centrifugation together with the cells. The freeze-dried sample contained 78% (w/w) of curdlan. The solubility and viscosity of the curdlan increased with the increase of the solution pH, which enhances the viscosity of concrete since the pH of concrete is extremely high (pH 13.0). Test results of the curdlan as a concrete admixture with cement slurry demonstrated that it prohibits the leakage of water. In conclusion, this work certifies and enlarges curdlan's industrial potential as a concrete admixture.

• Journal of The Korean Association For Science Education
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• v.20 no.3
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• pp.384-395
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• 2000

Recently performance assessments have been recommended as an alternative to traditional assessment methods such as multiple-choice written test. Performance assessment is suggested to facilitate students' creativity, participation and learning motivations in science classes. In this study, performance assessment materials were developed for a biology unit of middle school science 1, 'Plants Around Us', and then the assessment materials were applied to assess students' understandings and attitudes related to each topic of the unit. A total of 186 7th grade students at a southern large city participated in this study. From the study, the following were obtained: 1. Various type of the performance assessment materials, such as observation report, peer evaluation, interview have been developed for the unit 'Plants around us.' 2. Students' understandings on the topics appeared to be sound, and the students' interest and cooperative problem-solving abilities have been cultivated through the small group activities. The science classes became more student-centered. 3. Teacher's burden has increased due to the practices of performance assessment, but it could be handled by teacher's commitment and management skills. 4. The students' responses to performance assessments were positive, in general.

• Journal of the Korean earth science society
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• v.31 no.6
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• pp.563-572
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• 2010

Both multi-channel temperature monitoring and geophysical electric survey were performed together for an embankment to assess the leakage zone. Temperature variation according to space and time on the inner parts of engineering constructions (e.g.: dam and slope) can be basic information for diagnosing their safety problem. In general, as constructions become superannuated, structural deformation (e.g.: cracks and defects) could be generated by various factors. Seepage or leakage of water through the cracks or defects in old dams will directly cause temperature anomaly. This study shows that the position of seepage or leakage in dam body can be detected by multi-channel temperature monitoring using thermal line sensor. For that matter, diverse temperature monitoring experiments for a leakage physical model were performed in the laboratory. In field application of an old earth fill dam, temperature variations for water depth and for inner parts of boreholes located at downstream slope were measured. Temperature monitoring results for a long time at the bottom of downstream slope of the dam showed the possibility that temperature monitoring can provide the synthetic information about flowing path and quantity of seepage of leakage in dam body. Geophysical data by electrical method are also added to help interpret data.

• Journal of the Korean Institute of Gas
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• v.24 no.5
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• pp.10-19
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• 2020

Valve leak accidents in petrochemistry plants and gas utilities cause human and property damage. The main reason why happen gas inhalation, poisoning, fire and explosion accidents is gas valve leakage. To prevent gas leakage, inspectors check the facilities in the field. And they are at risk of gas leak accidents. So we applied IoT-based risk assessment, monitoring and automatic control system. It can detect both internal and external gas leakage, do real-time monitoring of industrial valve in the plant by using hybrid sensor. As the new safety management system for industrial valve is developed, it needs method to evaluate device performance and environmental components for the system. This study is about development of method to verify performance of the explosion-proofed hybrid sensing system include gas detector and optical fiber sensor supporting wire and wireless communication.