• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.227-234
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• 2007

The present study attempts to provide basic directions to respond to sea-level rise effectively based on the status of sea-level rise and its impact. The impact of the sea-level rise will be one of the most adverse component among climate change due to global warming. The basic approach to deal with sea level rise requires both mitigation and adaptation. Though the emission reduction can reduce a portion of sea level rise, the rising trend cannot be avoided due to the difficulty of the emission reduction and a strong inertia of the ocean. Therefore an effective corresponding direction has to focus on the development of appropriate adaptation strategies. Because sea level rise problem has scientific uncertainty, the corresponding system has to be designed to deal with the processes of information and awareness, planning and design, implementation, and monitoring and evaluation in continuous and long-term process. The future task to correspond effectively to the issue in Korea includes the improvement of scientific information, the development of adaptative measures, the enhancement of people awareness, the consensus of corresponding necessity, and formation of integrated corresponding system.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2016.05a
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• pp.404-430
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• 2016

This study started from the awareness of the issue if the citation index newly introduced to evaluate the quality of papers satisfies the proper timing matter, which is a component of performance indicators for the evaluation of government-funded R&D institutes. Accordingly, the study will propose improvement ways to shift the previous evaluation system to quality evaluation for mission-oriented R&D institutes by analysing and using the periodical characteristics such as citation half-life and immediacy index of papers. As a result, it turned out that the speed of academic change is getting faster in proportion to the dependency on the technological development but that the citation speed in the field of public technology is relatively slower and the speed of knowledge transfer in the fields related to industry is faster. In addition, the citation index among the R&D fields showed no differences, and the minimum period for citation index measurement with validity should be over 6 years. The problems of evaluation for mission-oriented R&D institutes were deducted based on the technical and statistical analysis results of the temporal characteristic of citation necessary for quality evaluation of performance among R&D fields. To solve the problems, policy alternatives for object and valid quality evaluation were proposed from the points of evaluation period, evaluation criteria, and evaluation management.

• Journal of Adhesion and Interface
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• v.4 no.1
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• pp.1-8
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• 2003

In this work, the effect of PMR-15 content on the variation of surface free energy of the DGEBA/PMR-15 blend system was investigated in terms of contact angles and mechanical interfacial tests. Based on FT-IR result of the blend system. C=O (1,772, $1,778cm^{-1}$) and C-N ($1,372cm^{-1}$) peaks appeared with imidization of PMR-15 and -OH ($3,500cm^{-1}$) peak showed broadly at 10 phr of PMR-15 by ring-opening of epoxy. Contact angle measurements were performed by using deionized water and diiodomethane as testing liquids. As a result, the surface free energy of the blends gave a maximum value at 10 phr of PMR-15, due to the significant increasing of specific component. The mechanical interfacial properties measured from the critical stress intensity factor ($K_{IC}$) and the critical strain energy release rate ($G_{IC}$) showed a similar behavior with the results of surface energetics. This behavior was probably attributed to The improving of the interfacial adhesion between intermolecules, resulting from increasing the hydrogen bondings of the blends.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.101-108
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• 2018

Objectives: The Korea National Health and Nutrition Examination Survey (KNHANES) is a national surveillance system that has been assessing the health and nutritional status of Koreans since 1998. Based on the National Health Promotion Act, the surveys have been conducted by the Korea Centers for Disease Control and Prevention (KCDC). Methods: An oral examination as part of The National Health and Nutrition Examination was proposed to calculate the sample design and survey participation. The surveying system was presented by classifying the measurement environment, screening, and survey items by year, and the merits and limitations of using the data were suggested by examining the status of survey quality management and the process of disclosing raw data. Results: This nationally representative cross-sectional survey samples approximately 10,000 individuals each year and collects information on oral examinations and oral health interviews. Data for the oral health component of KNHANES was obtained to assess the oral health status of Koreans and determine the prevalence of dental caries and periodontitis. The oral health data quality control of KNHANES was composed of three parts: "Education Program" and "Field Training Program" for quality control of oral health examiners (dentists) by the professional academy, and "Data management" by the KCDC. After completion of the three-step data check, the indicators of dental caries, periodontal disease, and oral health behavior were published in the National Health Statistics. Conclusions: To achieve the goals of oral health indicators, we will continue to monitor so that we can use it as basic data for oral policies and carry out various linkage analyses related to oral diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.339-346
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• 2019

Various studies have been conducted to evaluate the probabilistic fatigue life of steel railway bridges, but many of them are based on a relatively simple model of crack propagation. The model assumes zero minimum stress and constant loading amplitude, which is not appropriate for the fatigue life evaluation of railway bridges. Thus, this study proposes a new probabilistic method employing an advanced crack propagation model that considers the live-dead load ratio for the fatigue life evaluation of steel railway bridges. In addition, by using the rainflow cycle counting algorithm, it can handle variable-amplitude loading, which is the most common loading pattern for railway bridges. To demonstrate the proposed method, it was applied to a numerical example of a steel railway bridge, and the fatigue lives of the major components and structural system were estimated. Furthermore, the effects of various ratios of live-dead loads on bridge fatigue life were examined through a parametric study. As a result, with the increasing live-dead stress ratio from 0 to 5/6, the fatigue lives can be reduced by approximately 30 years at both the component and system levels.

• Korean Journal of Medicinal Crop Science
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• v.27 no.2
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• pp.96-107
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• 2019

Background: The aim of this study was to compare the fatty acid composition, antioxidant activity, and the content of two major phenolic acids, caffeic and rosmarinic acids, of 45 Perilla accessions collected from Russia. Methods and Results: A total of 45 accessions of the genus Perilla were used in this study. The antioxidant activities of these accessions were analyzed using a spectrophotometer, and their caffeic and rosmarinic acid contents were determined using a reversed-phase ultraperformance liquid chromatography (UPLC) system. The Perilla seed oil was recovered using hexane in a soxhlet extraction method. The fatty acid compositions were analyzed using a Shimadzu QP2010 gas chromatography-mass spectoroscopy system. The results showed that accessions IT226732 and IT274300 had the highest content of caffeic and rosmarinic acid, respectively. A cluster analysis based on antioxidant assay results and concentration of phenolic acids led to the categorization of Perilla accessions into three major groups. The accessions in Group I were characterized by higher caffeic and rosmarinic acid content and antioxidant activity, compared to the accessions in the other two groups (p < 0.05). The total oil content ranged between 28.39 and 46.89%. The compositions of oleic, linoleic, and linolenic acid ranged from 11.83 to 19.55%, 11.92 to 16.71%, and 59.19 to 67.28%, respectively. Conclusions: The results of this study indicated that accessions IT274300, IT226732, IT274293, IT235818, and IT235820 could be used as a source of functional materials.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.2
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• pp.123-131
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• 2021

The buffer is a key component of an engineered barrier system that safeguards the disposal of high-level radioactive waste. Buffers are located between disposal canisters and host rock, and they can restrain the release of radionuclides and protect canisters from the inflow of ground water. Since considerable heat is released from a disposal canister to the surrounding buffer, the thermal conductivity of the buffer is a very important parameter in the entire disposal safety. For this reason, a lot of research has been conducted on thermal conductivity prediction models that consider various factors. In this study, the thermal conductivity of a buffer is estimated using the machine learning methods of: linear regression, decision tree, support vector machine (SVM), ensemble, Gaussian process regression (GPR), neural network, deep belief network, and genetic programming. In the results, the machine learning methods such as ensemble, genetic programming, SVM with cubic parameter, and GPR showed better performance compared with the regression model, with the ensemble with XGBoost and Gaussian process regression models showing best performance.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.441-451
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• 2023

Ultrasound transducers are an essential component of combined photoacoustic and ultrasound imaging systems and play an important role in image evaluation. However, ultrasound transducers are opaque; therefore, light must bypass the ultrasound transducer to reach the target point to produce a photoacoustic image. Providing different paths for the optical and acoustic signals results in a complicated system design, increasing the system volume. To overcome these problems, an optically Transparent Ultrasound Transducer (TUT) was developed. Unlike conventional opaque ultrasound transducers, optically TUT can be fabricated by a variety of manufacturing methods and they are suitable for use with specific piezoelectric elements and serve various purposes. In this study, a comparative analysis of the results of using Lithium Niobate (LNO), Lead Magnesium Niobate-Lead Titanate (PMN-PT), and Polyvinylidene Difluoride (PVDF), which are materials used in piezoelectric element-based TUT. LNO is a piezoelectric element widely used in TUT, and PMN-PT has been actively studied recently with a higher transmission and reception rate than LNO. Existing TUT have lower ultrasound resolution than photoacoustic resolution, but they have recently been manufacturing focused TUT with high ultrasound resolution using PVDF. A comparative analysis of the production results of these TUT was performed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.199-208
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• 2023

Taguchi method is one of the most popular approaches for design optimization such that performance characteristics become robust to uncontrollable noise variables. However, most previous Taguchi method applications have addressed a single-characteristic problem. Problems with multiple characteristics are more common in practice. The multi-criteria decision making(MCDM) problem is to select the optimal one among multiple alternatives by integrating a number of criteria that may conflict with each other. Representative MCDM methods include TOPSIS(Technique for Order of Preference by Similarity to Ideal Solution), GRA(Grey Relational Analysis), PCA(Principal Component Analysis), fuzzy logic system, and so on. Therefore, numerous approaches have been conducted to deal with the multi-characteristic design problem by combining original Taguchi method and MCDM methods. In the MCDM problem, multiple criteria generally have different measurement units, which means that there may be a large difference in the physical value of the criteria and ultimately makes it difficult to integrate the measurements for the criteria. Therefore, the normalization technique is usually utilized to convert different units of criteria into one identical unit. There are four normalization techniques commonly used in MCDM problems, including vector normalization, linear scale transformation(max-min, max, or sum). However, the normalization techniques have several shortcomings and do not adequately incorporate the practical matters. For example, if certain alternative has maximum value of data for certain criterion, this alternative is considered as the solution in original process. However, if the maximum value of data does not satisfy the required degree of fulfillment of designer or customer, the alternative may not be considered as the solution. To solve this problem, this paper employs the desirability function that has been proposed in our previous research. The desirability function uses upper limit and lower limit in normalization process. The threshold points for establishing upper or lower limits let us know what degree of fulfillment of designer or customer is. This paper proposes a new design optimization technique for multi-characteristic design problem by integrating the Taguchi method and our desirability functions. Finally, the proposed technique is able to obtain the optimal solution that is robust to multi-characteristic performances.

• Journal of Korean Medicine Rehabilitation
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• v.33 no.4
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• pp.31-44
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• 2023

Objectives The purpose of this study is to check the research trends of pharmacopuncture treatment in nerve entrapment syndrome, identify specific techniques, identify which pharmacopuncture are used, and provide directions for future research. Methods This study was conducted based on the five steps suggested by Arksey and O'Malley. We searched five domestic databases (Research Information Sharing Service, Oriental Medicine Advanced Searching Integrated System, Korean studies Information Service System, Science ON, and KMBASE) and identified studies with key search terms like "nerve entrapment" And "pharmacopuncture" until June 23, 2023. Results Twenty-nine studies were finally selected. among them, 25 papers were non-comparative studies (86.2%). The most common disease was carpal tube syndrome (n=10). All the investigated studies were treated by injecting pharmacopuncture into the pathway of the entraped nerve. The depth of pharmacopuncture injection was mentioned only in 13 studies. As for the pharmacopuncture used, sweet bee venom was 8 studies and bee venom was 6 studies, and about half of the pharmacopuncture manufactured with Bee venom as the main component accounted for. Conclusions This study is a scoping review of the pharmacopuncture treatment for nerve entrapment, which was first conducted in Korea. The treatment is mainly performed on the path way of the entraped nerve. After that, it is necessary to study the standardization of the specific technique method of pharmacopuncture and the uniformity of evaluation criteria.