• Mineral and Industry
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• v.18 no.1
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• pp.1-17
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• 2005

국내의 납석 광상은 대부분 백악기의 화산암류들이 열수변질되어 형성된 광상으로서, 주로 전남 및 경남 지역에 밀집되어 분포한다. 납석은 지질 여건상 주로 경상분지 내에 국제적인 규모의 풍부한 부존자원이 있지만, 그 동안의 개발에 의해서 고품위 황석들은 상당히 채진된 상황이다. 현재 개발되고 있는 광체들은 몇 곳의 광산을 제외하고는 대부분 저품위 광상을 이루고 있기 때문에, 새로운 광체의 탐광이 이루어지지 않는다면 앞으로 고품위 광석에 관한 한 국내의 수요를 충당하기 어려운 상황에 이를 것으로 예견된다. 현재 국내에서 납석으로 개발되고 있는 광석의 상당수(대략 $40\%$ 정도)가 엄밀한 의미에서는 사실상 납석이 아닌 고령토나 견운모 광석인 것으로 밝혀졌다. 엽납석을 함유하는 정상적인 형태의 납석들은 그수반 점토광물상에 의거하여 (l) 엽납석질, (2) 딕카이트질. (3) 일라이트질 및 (4) 딕카이트-일라이트질 유형으로 구분될 수 있다. 고령토 광물로는 대부분 딕카이트가 수반되고 외국에서는 흔히 수반되는 것으로 알려져 있는 고령석은 거의 함유되지 않는 것이 특징이다. 석영은 납석에서 점토광물 못지않게 그 용도를 가름하는 주요 성분으로서 대부분의 광석 유형에서 수반되지만 특히 일라이트질 납석에서 흔히 그리고 보다 많이 수반되는 양상을 보인다. X-선회절 정랑분석법은 납석의 품위를 산정하는데 유력한 수단이 될 수 있다. 특히 납석 이외의 점토광물들의 조성, 특히 일라이트의 함유 정도는 납석의 용도별 품위와 품질을 가름하는 주요 사항이다. 화학분석에 의한 납석의 평가 방식은 특히 납석의 백색 도기류와 같은 각종 세라믹스 제조 용도에서의 품질 평가에 결정적인 단서를 제공하는 유력한 평가수단이다. 특히 착색유발 성분인 철분의 존재와 그 함량을 정하고 요업용도에서 중요한 $Al_3O_3$와 알칼리 성분 함량을 검증하는데 필수적인 평가 방법이다. 이외에 주사전자현미경 관찰을 통해서 납석의 주요 품질 기준이 되는 극미립상 엽납석의 결정형, 조직 및 미시적 산출상태를 보다 정밀하게 평가할 수 있는 방안을 제공한다. 현행 광업법상의 납석을 비롯한 관련 광종들의 광물분류 체계가 모호하게 설정되어 있고 관련 인허가 부서에서의 전문성 및 지도력 부족으로 관련 산업계에 심각한 비효율성과 오류가 야기되고 있는 실정이다. 이를 개선하기 위해서는 납석의 광석평가 방식이 그 품위와 품질 개념 하에서 응용광물학적으로 적용되어야 할 것이다.

• Journal of KIISE:Software and Applications
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• v.32 no.7
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• pp.674-682
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• 2005

This paper proposes classification of multi-spectral satellite image based on fusion of fuzzy G-K (Gustafson-Kessel) algorithm and PCM algorithm. The suggested algorithm establishes the initial cluster centers by selecting training data from each category, and then executes the fuzzy G-K algorithm. PCM algorithm perform using classification result of the fuzzy G-K algorithm. The classification categories are allocated to the corresponding category when the results of classification by fuzzy G-K algorithm and PCM algorithm belong to the same category. If the classification result of two algorithms belongs to the different category, the pixels are allocated by Bayesian maximum likelihood algorithm. Bayesian maximum likelihood algorithm uses the data from the interior of the average intracluster distance. The information of the pixels within the average intracluster distance has a positive normal distribution. It improves classification result by giving a positive effect in Bayesian maximum likelihood algorithm. The proposed method is applied to IKONOS and Landsat TM remote sensing satellite image for the test. As a result, the overall accuracy showed a better outcome than individual Fuzzy G-K algorithm and PCM algorithm or the conventional maximum likelihood classification algorithm.

• Journal of the Korean Geotechnical Society
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• v.36 no.6
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• pp.35-46
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• 2020

The input parameters for numerical simulation of the liquefaction phenomenon need to be properly evaluated from laboratory and field tests, which are difficult to be performed in practical situations. In this study, the numerical simulation of the cyclic direct simple shear test was performed to analyze the applicability of Finn and PM4Sand models among the constitutive models for liquefaction simulation. The analysis results showed that the Finn model properly predicted the time when the excess pore water pressure reached the maximum, but failed to simulate the pore pressure response and the stress-strain behavior of post-liquefaction. On the other hand, the PM4Sand model properly simulated those behaviors of the post liquefaction. Finally, the evaluation procedure and the equations of the input parameters in the PM4Sand model were developed to mach the liquefaction cyclic resistance ratio corresponding to design conditions.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.217-228
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• 2021

After the integrated fare system has been applied, public transportation and transfer traffic increased. As a result, transfer passengers must be considered in the operation of the bus. Although previous studies have limitations due to utilizing deterministic mathematical models, which fails to reflect the stochastic movements of passengers and buses, in this study, a more realistic bus stop micro-simulation model is proposed. Based on the proposed simulation model, we represent the relationship between bus arrival interval and passenger wait time as a regression model and empirically show the differences between the cases with and without transfer passengers. Also, we propose a method converting passenger waiting time to cost and find optimal bus arrival interval based on the converted cost. It is expected the proposed method enables bottom-up decision making reflecting practical situation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.268-275
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• 2020

A lightweight hardware design of self-timed ring based true random number generator (TRNG) suitable for information security applications is described. To reduce hardware complexity of TRNG, an entropy extractor with feedback structure was proposed, which minimizes the number of ring stages. The number of ring stages of the FSTR-TRNG was determined to be a multiple of eleven, taking into account operating clock frequency and entropy extraction circuit, and the ratio of tokens to bubbles was determined to operate in evenly-spaced mode. The hardware operation of FSTR-TRNG was verified by FPGA implementation. A set of statistical randomness tests defined by NIST 800-22 were performed by extracting 20 million bits of binary sequences generated by FSTR-TRNG, and all of the fifteen test items were found to meet the criteria. The FSTR-TRNG occupied 46 slices of Spartan-6 FPGA device, and it was implemented with about 2,500 gate equivalents (GEs) when synthesized in 180 nm CMOS standard cell library.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.1
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• pp.62-68
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• 2022

Due to medical and economic development, various treatment methods are being studied to restore or maintain beautiful and healthy teeth. In particular, interest in aesthetic treatment procedures such as prosthetic treatment and whitening to restore tooth loss is increasing. One of the important things in the field of prosthetics and esthetic treatment is to determine the correct color of teeth because harmony with natural teeth is an important factor in determining the perfection of esthetic prostheses. This study is about the development of a colorimetry application for tooth colorimetry using a smartphone camera. The colorimetry application UI was designed, the colorimetry algorithm was derived and the application was implemented, and the validity of the application was verified through testing the implemented application.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.1
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• pp.35-40
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• 2022

In this paper, we propose a method of constructing clinical knowledge with clinical concept relations and predicting diseases based on a deep learning model to support clinical decision-making. Clinical terms in UMLS(Unified Medical Language System) and cancer-related medical knowledge are classified into five categories. Medical related documents in Wikipedia are extracted using the classified clinical terms. Clinical concept relations are established by matching the extracted medical related documents with the extracted clinical terms. After deep learning using clinical knowledge, a disease is predicted based on medical terms expressed in a query. Thereafter, medical terms related to the predicted disease are selected as an extended query for clinical document retrieval. To validate our method, we have experimented on TREC Clinical Decision Support (CDS) and TREC Precision Medicine (PM) test collections.

• Korean Journal of Construction Engineering and Management
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• v.23 no.5
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• pp.56-64
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• 2022

Although pilot projects have been actively carried out from 2017 to present to institutionalize CM at Risk, one of the major tasks for innovation in the construction industry, standards and processes related to Design VE, a key tool for determining GMP in the pre-construction phase, have not yet been established. Therefore, through research and operation status related to CM at Risk and Design VE, and survey on project participants' perception, the problem of the existing design VE process was derived, and the design VE process suitable for the CM at Risk project was proposed. The application plan was proposed in three aspects: Schedule, Cycle, and Process, and the appropriateness and applicability were verified through FGI. The results of this study are expected to be used as basic data on the establishment and legislation of order standards to be made in the future.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.568-573
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• 2023

Range resolution is the ability to distinguish different targets placed in same angular direction but at different distances from the radar. Normally, Range resolution requirement is defined as the width of transmitting pulse. The width of transmitting pulse does not mean the ability to distinguish two different targets. Range resolution performance to detect and track targets separately depends on the signal processing and tracking algorithm not only the width of transmitting pulse. This paper analyzes the processing steps in algorithms to affect the range resolution performance and verifies the results by roof-lab ground test using beacon signal. As a result, to track targets with the same angular position separately, it is desirable to have larger range difference than plot-track association test gate.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.36 no.2
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• pp.61-69
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• 2024

Wave conditions are crucial for offshore wind farm design, particularly in determining structural loads and layout. However, there is limited wave hindcasting research for the Wangdeungdo Island area, a potential offshore wind site. This study used the MIKE21 model for a year-long wave hindcast around Wangdeungdo in 2021. Validation showed high reproducibility for significant wave heights with RMSE values of 0.177 and 0.225 and Pearson correlations of 0.971 and 0.970 at Sangwangdeungdo and Buan buoys. Subsequent analysis of the wave characteristics near Wangdeungdo indicated significant seasonal variations and differences in maximum significant wave heights across locations, which are expected to significantly impact the design loads for offshore wind structures.