• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.1
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• pp.11-19
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• 2013

Backgrounds: Occupations are grouped on the basis of similarity in tasks and duties performed. Standard occupational classification (SOC) is a tool for organizing all professions into a clearly defined set of groups according to the tasks and duties undertaken in the respective jobs. Objectives: The major objective of this study is to comprehensively review how a SOC system is used in occupational and safety fields such as surveillance, exposure monitoring, occupational epidemiological study, management of carcinogens and analysis of occupational accidents. Methods: We summarized the cases, policies and regulations used in SOC systems in advanced countries and as they appear in articles Results: We found that SOC systems have been widely used in various areas of occupational safety and health in the US, the UK, Finland, and the EU. In general, it is highly common to use SOC in the analysis of occupational accidents and diseases and to identify factors causing those accidents. The SOC system is also used not only for surveillance of exposure to hazardous agents and occupational health, but to manage carcinogens. In order to adjust the effects of a particular job, SOC is used in the general population health area. The Ministry of Employment and Labor (MOEL) has never used or introduced an SOC system. There have been no cases of the application of a SOC system to either the occupational safety and health field or to health surveillance for the general population in Korea. Conclusions: We suggested a need to introduce an SOC system in several occupational safety and health activities, such as work environment measurement, analysis of occupational accidents, specific physical examination and surveillance systems, etc.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.3 s.246
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• pp.278-286
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• 2006

Experiments were conducted to estimate the performance of drag force type vertical axis wind turbine with an opening-shutting rotor. It was operated by the difference in drag force generated on both sides of the blades. The rotational speed was measured by a tachometer in a wind tunnel and the tunnel wind speed was measured by using a pilot-static tube and a micro manometer. The performance test for a prototype was accomplished by calculating power, power coefficient, torque coefficient from the measurement of torque and rpm by a dynamometer controller. Various design parameters, such as the number of blades(B), blade aspect ratio(W/R), angle of blades$(\alpha)$ and drag coefficient acting on a blade, were considered for optimal conditions. At the experiment of miniature model, maximum efficiency was found at N=15, $\alpha=60^{\circ}$ and W/R=0.32. The measured test variables were power, torque, rotational speed, and wind speeds. The data presented are in the form of power and torque coefficients as a function of tip-speed ratio V/U. Maximum power was found in case of $\Omega=0.33$, when the power and torque coefficient were 0.14 and 0.37 respectively. Comparing model test with prototype test, similarity law by advance ratio for vertical axis wind turbine was confirmed.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.11
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• pp.147-155
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• 2015

For the image processing system to be classified the selected object in the nature, the rotation, scale and transition invariant features is to be necessary. There are many investigations to get the information for the object processing system and the log-polar transform which is to be get the invariant feature for the scale and rotation is used. In this paper, we suggested the 2 points polar coordinate transform methods to measure the selected object position out of the center in input image including the centroid method. In this proposed system, the position results of objects are very good, and we obtained the similarity ratio 99~104% for the object coordinate values.

• Women's Health Nursing
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• v.4 no.1
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• pp.67-83
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• 1998

A quasi-experiment, repeated measures design with non-equivalent control group was used to test the influence of cold therapy on the perineal discomfort and the healing state of the postpartum women undergoing vaginal delivery with episiotomy. Experiment was carried out from July 28, through October 2, 1996 with 40 postpartum women conveniently sampled from one university hospital located in Seoul. The 40 postpartum women undergoing vaginal delivery with episiotomy were as signed to experimental and control groups evenly(20 each). The instrument of measurement of perineal discomfort was 0-10 rating scale that was made by researcher and that of perineal healing state was Davidson's REEDA tool. The perineal discomfort and the healing state level were measured before and after each treatment. The treatment using ice glove that was given for the only experimental group was carried out at three points ; as soon as returning to the recovery room, 3 hours after returning to the recovery room and 6 hours after returning to the recovery room. The data was analysed by using t-test, chi-square test to determine the similarity between experimental and control groups. The hypotheses were tested using repeated measures ANOVA. The results of this study are summarized as follows; 1. The first hypothesis that the perineal discomfort level of the experimental group will be significantly lower than that of the control group(df(1,38), F=24.12, p=.0001) was supported. 2. The second hypothesis that the perineal healing state of the experimental group wil be better than that of the control group(df(1,38), F=0.48, p=.49) was not supported. Based on the results of this study, could therapy was turned out to have significant effect on the perineal discomfort of the postpartum women undergoing vaginal delivery with episiotomy.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.258-268
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• 2019

The extracts of AS contain in alloxanthin, halocynthiaxanthin, astaxanthin and 13 kinds of carotenoids. The aim of the study was to assess the anti-oxidant activity and cell viability of AS. The anti-oxidant activity was determined by using DPPH radical inhibition activity and superoxide dismutase (SOD)-like activity. The results of cell viability assay showed that the extracts from AS were cytotoxic at concentrations above $5.0mg/m{\ell}$. This study was designed to examine inflammation induced by LPS, protection effect by UVB and the toxicity of Ascidian shell extract(ASE) as a functional cosmetic ingredient. Evaluation of embryo toxicity resulted in embryo coagulation and mortality when treated at 5.0, 10.0, $20.0mg/m{\ell}$. At the lowest concentration of $1.0mg/m{\ell}$, hatchability resulted in 100.0 % rate. The results of arrhythmia measurement in larvae showed similarity to the evaluation of embryo toxicity. This result demonstrated that toxicity is present at concentrations greater than $5.0mg/m{\ell}$. The protective effect of ASE on LPS and UVB-induced in the zebrafish was investigated. Intracellular reactive oxygen species(ROS) generated by the exposure of zebrafish to LPS, UVB-radiation were significantly decreased after treatment with ASE at $0.1mg/m{\ell}$. As a result, ASE similarly reduced UVB-induced ROS generation and cell death in live zebrafsih. Therefore, it is suggested that ASE has anti-Inflammatory effects and can possibly be used as a functional substance for skin protection in the future.

• Journal of Korea Trade
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• v.23 no.2
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• pp.1-13
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• 2019

Purpose - This paper empirically investigates the competition effect of exports between Korea and China in their common-export markets considering market sophistication. Modern market sophistication includes an importing country's aggregate demand for products of high quality, design, novelty, eco-friendliness, and even IPR protection. Using an empirical analysis to identify the demand for product quality across countries, this paper estimates the effects of market sophistication on the competition between Korean exports and Chinese products. Design/Methodology - Our empirical model considers the relationship between an importing country's consumer sophistication and the export competition between Korea and China. This study employs the existing theoretical framework to identify the aggregate demand for product quality across countries. Using a quite direct measurement (the consumer sophistication index, our analysis investigates the differential effects of Korea's export market sophistication, particularly in markets where Korean exports are in competition with similar Chinese products. Findings - Our main findings can be summarized as follows: the negative effects of the export competition between Korea and China on Korea's exports are stronger in third markets where consumers are less sophisticated while the effects are not as pronounced in markets where consumers are more sophisticated. This result, however, best applies to differentiated goods which significantly vary in product quality. Originality/value - Existing studies focus on the supply side of production and make the assumption that the market preference for export quality is identical across countries. This paper attempts to evaluate the export competition between Korea and China from the demand-side perspective. This area of trade studies is underexplored both empirically and in theory, although the issue has long been important to Korean and world trade.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.1-12
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• 2022

As the music streaming service and the Hi-Fi market grow, various audio devices are being released. As a result, consumers have a wider range of product choices, but it has become more difficult to find products that match their musical tastes. In this study, we proposed a system that extracts the vocal component from the user's preferred sound source and recommends the most suitable audio device to the user based on this information. To achieve this, first, the original sound source was separated using Python's Spleeter Library, the vocal sound source was extracted, and the result of collecting frequency band data of manufacturers' audio devices was shown in a grid graph. The Matching Gap Index (MGI) was proposed as an indicator for comparing the frequency band of the extracted vocal sound source and the measurement data of the frequency band of the audio devices. Based on the calculated MGI value, the audio device with the highest similarity with the user's preference is recommended. The recommendation results were verified using equalizer data for each genre provided by sound professional companies.

• Journal of Biomedical Engineering Research
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• v.44 no.2
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• pp.139-146
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• 2023

Osteoporosis is a disease in which the risk of bone fractures increases due to a decrease in bone density caused by aging. Osteoporosis is diagnosed by measuring bone density in the total hip, femoral neck, and lumbar spine. To accurately measure bone density in the lumbar spine, the vertebral region must be segmented from the lumbar X-ray image. Deep learning-based automatic spinal segmentation methods can provide fast and precise information about the vertebral region. In this study, we used 695 lumbar spine images as training and test datasets for a deep learning segmentation model. We proposed a lumbar automatic segmentation model, CM-Net, which combines the center point of the spine and the modified U-Net network. As a result, the average Dice Similarity Coefficient(DSC) was 0.974, precision was 0.916, recall was 0.906, accuracy was 0.998, and Area under the Precision-Recall Curve (AUPRC) was 0.912. This study demonstrates a high-performance automatic segmentation model for lumbar X-ray images, which overcomes noise such as spinal fractures and implants. Furthermore, we can perform accurate measurement of bone density on lumbar X-ray images using an automatic segmentation methodology for the spine, which can prevent the risk of compression fractures at an early stage and improve the accuracy and efficiency of osteoporosis diagnosis.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.315-327
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• 2023

Purpose: Recently, research has continued to predict the time of failure of the facility through measurement data obtained by attaching a sensor to the facility. However, depending on the facility, it may be difficult to attach a sensor. The purpose of this study is to propose a power generation maintenance plan system based on failure record data obtained from Continuous Ship Unloader, one of the facilities that is difficult to attach sensors. Methods: This study uses data collected from 2012 to 2022 from the 'CSU-1B' model among Continuous Ship Unloader operated by Korea Midland Power Co., LTD. By fitting fault record data to the Weibull distribution, appropriate maintenance cycles and ranges for each target facility subsystem are derived. In addition, maintenance group between subsystems is selected through Euclidean distance, a metric often used for time series data similarity. Through this, a system for establishing an maintenance plan for power generation facilities is proposed. Results: The results of this study are as follows. For the 17 subsystems of the Continuous Ship Unloader, proper maintenance cycles and ranges were determined, and a total of four maintenance groups were chosen. This resulted in the creation of an power generation maintenance plan system and the establishment of an maintenance plan. Conclusion: This study is a case study of power generation facilities. We proposed a maintenance plan system for Continuous Ship Unloader among power generation facilities.

• The Journal of the Acoustical Society of Korea
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• v.25 no.4
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• pp.151-158
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• 2006

In this paper, we proposed a new audio fingerprint extraction method, based on Philips' music retrieval algorithm, which uses the energy difference of neighboring filter-bank and probabilistic characteristics of music. Since Philips method uses too many filter-banks in limited frequency band, it may cause audio fingerprints to be highly sensitive to additive noises and to have too high correlation between neighboring bands. The proposed method improves robustness to noises by reducing the number of filter-banks while it maintains the discriminative power by representing the energy difference of bands with 2 bits where the quantization levels are determined by probabilistic characteristics. The correlation which exists among 4 different levels in 2 bits is not only utilized in similarity measurement. but also in efficient reduction of searching area. Experiments show that the proposed method is not only more robust to various environmental noises (street, department, car, office, and restaurant), but also takes less time for database search than Philips in the case where music is highly degraded.