• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.112-118
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• 2022

In this study, the diffusion characteristics were evaluated using the concrete mix design of nuclear safety-related structures. Among the concrete structures related to nuclear power safety, we selected the composition of intake and drainage structures that are immersed in seawater or located on the tidal platform and evaluated the chloride ion permeation resistance by compressive strength and electrical conductivity and the diffusion characteristics by immersion in salt water. analyzed. Compressive strength was measured on the 1st, 7th, 14th, 28th, 56th, and 91st days until the 91st day, which is the design standard strength of the nuclear power plant concrete structure, and chloride ion permeation resistance was evaluated on the 28th and 91st. After immersing the 28-day concrete specimens in salt water for 28 days, the diffusion coefficient was derived by collecting samples at different depths and analyzing the amount of chloride. As a result, it was found that after 28 days, the long-term strength enhancement effect of the nuclear power plant concrete mix with 20% fly ash replacement was higher than that of concrete using 100% ordinary Portland cement. It was also found that the nuclear power plant concrete mix has higher chloride ion permeation resistance, lower diffusion coefficient, and higher resistance to salt damage than the concrete mix using 100% ordinary Portland cement.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.17-27
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• 2022

A certain level of stability margin airworthiness criteria should be met to secure robustness against uncertainties between the real plant and the model in a flight control system design. The U.S. Department of Defense (DoD) specification of MIL-F-9490D and airworthiness certification standard of MIL-HDBK-516B uses gain and phase margin criteria of flight control system. However, the same stability margin criteria is applied at all development phases without considering the design maturity of each development phase of the aircraft. Ultimately, a problem arises when the aircraft operation envelope is excessively restricted. This paper proposes the relation of handling qualities and stability margin, and presents re-established stability margin criteria as a development phases and verification methods. The results of the research study are considered to contribute to the verification of the stability margin criteria more flexibly and effectively by applying the method to not only the currently manned developing aircrafts but also the unmanned vehicle to be developed in the future.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.29-39
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• 2023

In the recent period, there have been numerous earthquakes both domestically and internationally, and buildings in South Korea are particularly vulnerable to seismic design and earthquake damage. Therefore, the objective of this study is to discover an effective method for assessing the seismic vulnerability of buildings and conducting a density analysis of high-risk structures. The aim is to model this approach and validate it using data from pilot area(Seoul). To achieve this, two modeling techniques were employed, of which the predictive accuracy of the statistical analysis technique was 87%. Among the machine learning techniques, Random Forest Model exhibited the highest predictive accuracy, and the accuracy of the model on the Test Set was determined to be 97.1%. As a result of the analysis, the district rating revealed that Gwangjin-gu and Songpa-gu were relatively at higher risk, and the density analysis of at-risk buildings predicted that Seocho-gu, Gwanak-gu, and Gangseo-gu were relatively at higher risk. Finally, the result of the statistical analysis technique was predicted as more dangerous than those of the machine learning technique. However, considering that about 18.9% of the buildings in Seoul are designed to withstand the Seismic intensity of 6.5 (MMI), which is the standard for seismic-resistant design in South Korea, the result of the machine learning technique was predicted to be more accurate. The current research is limited in that it only considers buildings without taking into account factors such as population density, police stations, and fire stations. Considering these limitations in future studies would lead to more comprehensive and valuable research.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.1
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• pp.50-56
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• 2007

Impact of thermal discharge of nuclear power plant on marine environment is naturally reflected in biogeochemical changes of seawater. Until now, many investigation activities and reports of impact analysis of marine environment were occasionally inadequate to provide sufficient justification in resolving controversial conflict of interests related with thermal discharge of nuclear power plant. From the scrutinized examination of recent 17 reports published in Korea between 2002 and 2004, the most apparent issue was inadequacy of sampling design and absence of significance of many measured parameters. In many cases, lack of statistical interpretation of raw data incurred subjective or ambiguous assessment results, which failed in deducing mutual concurrence between the parties of interest. In overall all, the main reasons for impairing integrity of previous reports seem to be inconsistency of environmental investigation procedures between research institutions, inadequate sampling design at the discretion of institutions and lack of objectivity of impact assessment based on statistical interpretation. Therefore, the primary goal of this study is to (1) discuss the blown issues on previous routine practice of seawater quality assessment procedures, and to (2) provide improved investigation procedures and rational standard criteria strictly based on statistical analysis for the better seawater quality assessment, which could be supported by scientific community, public agency, investigation institution and the other parties of interest.

• Food Science and Preservation
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• v.22 no.5
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• pp.652-659
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• 2015

The physical properties of wheat kernels were determined as a function of moisture content to optimize the design of equipment for post-harvest management. Several properties, including bulk density, dynamic repose angle, one thousand-kernel weight, specific gravity, length, width, thickness, and area of two wheat cultivars (Baekjjung: B and Jogyeong: J ), were studied in the moisture range from approximately 9% to 30% wet basis. As moisture increased, length increased linearly from 6.42 to 7.20 mm (B) and 8.71 to 9.15 mm (J), width increased from 2.90 to 3.49 mm (B) and 4.12 to 4.43 mm (J), thickness from 2.94 to 3.20 mm (B) and 3.29 to 3.63 mm (J), and area from 14.13 to $19.44mm^2$ (B) and 27.75 to $31.25mm^2$ (J). Additionally, the dynamic repose angle and one thousand-kernel weight increased linearly from $46.3^{\circ}$ to $54.0^{\circ}$ (B) and $46.3^{\circ}$ to $54.5^{\circ}$ (J) and from 32.26 to 41.51 g (B) and 45.30 to 63.07 g (J), respectively, as the moisture content increased. Based on the experimental measurements, only the bulk density and specific gravity decreased from 754.0 to $664.1kgm^{-3}$ (B) and 776.1 to $660.0kgm^{-3}$ (J) and from 1.2950 to 1.2265 (B) and 1.3379 to 1.2671 (J), respectively, as moisture content increased.

• Korean Journal of Construction Engineering and Management
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• v.6 no.2 s.24
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• pp.120-128
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• 2005

ISO 9001, the quality management system issued by the International Organization for Standardization, is being used by architectural design and engineering firms in order to strengthen the capability of business activities through the implementation of the international and advanced quality management systems. However, there have been significant problems in stable implementation and settlement of ISO 9001 in construction industry, which seem to be caused by key employees' lack of proper recognition and comprehension. The purpose of this research, accordingly, is to find and analyze nonconformity results which were found when the third party registrars audited the conformity of companies' quality management systems for ISO 9001 certification especially in architectural design and engineering firms. For this purpose this research was conducted by a cluster analysis of 647 audit reports out of representative 15 architectural design and engineering firms that have been audited periodically from 1997 to 2003 by the third party registrars. The analysis showed that the most frequent problems were generated in the areas of $\ulcorner$Design and Development$\lrcorner$ , $\ulcorner$production and Service Provision$\lrcorner$ , and $\ulcorner$General requirements$\lrcorner$ of the quality management system. The following, the areas of $\ulcorner$Monitoring and Measurement$\lrcorner$ and $\ulcorner$purchasing$\lrcorner$ were also analyzed as main factors which caused frequent nonconformity results. This research also shows that the corrective actions for nonconformity results are closely connected with the whole management activities in architectural design and engineering firms. Consequently, corrective actions for disposition of nonconformities should be implemented more specifically in order to settle and activate the quality management systems in architectural design and engineering firms.

• Women's Health Nursing
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• v.1 no.2
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• pp.200-221
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• 1995

The confusion of the sense of value on sex is increasing because of the rapid change in social-cultural environment. Also due to a rise in the standard of living, the age of adolescence is getting lower, and so the second sexual marks appear to primary schoolers. At this time in the aspect of the education for the whole man, it's very important for primary schoolers to acquire right knowledge and desirable attitude on sex so that can overcome psychological instability caused by physical growth, be responsible for their behaviors and lead happy lives. This study was made to find out the effects of sex education for the primary schoolers' knowledge and attitude about sex. The study was designed as simulated control group pretest-posttest design, which only pretest was practiced to control group and after sex education only posttest was practiced to experimental group. The data was collected for 18 days from March 13, 1995 to March 31, 1995. The subjects of this study were 130 six-graders in a private primary school in seoul. The control group and experimental group were composed of 65 pupils, each. Sex education consisted of lecture and discussion and the materials were this researcher's own made, 'How do I grow? and related OHP film and video. This education was practiced 40 minutes at a time, at intervals of 2-4 days' six times during 3weeks. For sex knowledge tools, 20 item questionaries on the base of related reference books and contents of this study were used. For sex attitude tools, this researcher's own made 13 item questionaries were used which were revised and complemented and laying stress on the reference books. The data was analyzed through pc-SAS program. The homogeneity test in terms of the general characteristics of experimental and control group was analyzed through $x^2$-test and t-test. And the difference in the primary schoolers' score on knowledge and attitude about sex before and after the sex education was analyzed through t-test and ANCOVA. The results of this study are as follows : 1. The result of the homogeneity test in terms of the general characteristics of the experimental and control group showed that there were significant differences in economic standard($x^2$=2.92, P=0.052) and brotherly ties($x^2$=3.78, P=0.052). 2. Hypothesis 'After sex education, the score of primary schoolers' sex knowledge will be higher than before. 'showed statistically significant difference.(t=11.99, P=.0001) Sex education was practiced under control over subjective view of economic standard and brotherly ties which showed significant difference at the homogeneity test in terms of the general characteristics between the two groups. After this education, the results of comparing the score of primary schoolers' sex knowledge also showed significant difference between the two groups. So hypothesis I was supported since primary schoolers to have education showed noticeable results in the sex knowledge score. (F=16.52, P=.0001) 3. Hypothesis 'After sex education, primary schooler's sex attitude score will be higher than before' showed statistically significant(t=5.08, P=.0001) Sex education was practiced, too, under control over subjective view of economic standard and brotherly ties which showed significant difference at the homogeneity test in terms of the general characteristics between the two groups. Bat this time the results of comparing the primary schoolers' sex attitude showed no significant difference between the two groups. So hypothesis II was rejected since for primary schoolers to have sex education showed no noticeable results in sex attitude score. (F=3.52, P=.0628) These results of the study show that sex education gives affirmative change to the primary schooler's sex knowledge, bat short periods' sex education doesn't give any change to the sex attitude. For the establishment of the pupils' desirable sex attitude, systematic and concrete sex education fit for the pupils' developing stage should be practiced over a long period of time.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.226-234
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• 2015

To provide the data necessary to determine exposure coefficients used for calculating the snow load acting on a greenhouse, we compared the exposure coefficients in the greenhouse structure design standards for various countries. We determined the exposure coefficient for each region and tried to improve on the method used to decide it. Our results are as follows: After comparing the exposure coefficients in the standards of various countries, we could determine that the main factors affecting the exposure coefficient were terrain roughness, wind speed, and whether a windbreak was present. On comparing national standards, the exposure coefficients could be divided into three groups: exposure coefficients of 0.8(0.9) for areas with strong winds, 1.0(1.1) for partially exposed areas, and 1.2 for areas with dense windbreaks. After analyzing the exposure coefficients for 94 areas in South Korea according to the ISO4355 standard, all of the areas had two coefficients (1.0 and 0.8), except Daegwallyeong (0.5) and Yeosu (0.6), which had one coefficient each. In South Korea, the probability of snow is greater inland than in coastal areas and there are fewer days with a maximum wind velocity > $5m{\cdot}s^{-1}$ inland. When determining the exposure coefficients in South Korea, we can subdivide the country into three regions: coastal areas with strong winds have an exposure coefficient of 0.8; inland areas have a coefficient of 1.0; and areas with dense windbreaks have an exposure coefficient of 1.2. Further research that considers the number of days with a wind velocity > $5m{\cdot}s^{-1}$ as the threshold wind speed is needed before we can make specific recommendations for the exposure coefficient for different regions.

• Journal of Acupuncture Research
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• v.26 no.6
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• pp.101-110
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• 2009

Objectives : We developed and proposed a guideline for safety and performance assessment of electric cupping apparatus(Class 2 medical device). Methods : We drafted the guideline for safety and performance assessment of electric cupping apparatus by referring the existing standards and guideline, based on online questionnaire for Korean medical doctors and measurement data from commercially available products. Physical dimension of cups and inner vacuum pressure were acquired for the measurement in order to achieve the purposes. Results : This guideline only can be applied to electric cupping apparatus for enhancing blood circulation by employing negative pressure generated by electricity. Seven items of appearance and label, operation test of pump, variation test of input electricity, vacuum level test, vacuum sustain test, cup-size dependent test, noise level test are suggested for evaluation subjects and methods required for electric cupping devices. Requirements for the design and development of electric cupping devices are suggested: vacuum level indicator, vacuum generation rate, pressure control, valve detachment stability, cup comparability, safety measure, surge protection, user friendliness, instruction for use (IFU). Conclusions : We proposed a guideline for safety and performance assessment of electric cupping apparatus to improve the quality of relating products and aid the commercialization of them, by aiming higher industrial competitiveness of the medical device sectors in Korea. Discussion with related institutes such as industry, academy and government is further required. Public hearings also need to be held prior to the establishment of a final guideline and standard.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.6
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• pp.106-117
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• 2003

The advanced medical information systems usually consist of loosely-coupled interaction of independent systems, such as HIS/RIS and PACS. To support easier information exchange between these systems and between hospitals, and to support new types of medical service such as teleradiology, it becomes essential to integrate separated medical information and allow them to be exchanged and retrieved through internet. This thesis proposes an integrated medical information system using XML. We analyzed HL7 and DICOM standard formats, and designed an integrated XML DTD. We extracted information from HL7 messages and DICOM files and generated XML document instances and XSL stylesheets based on the proposed XML DTD. We implemented the web interface for the integrated medical information system, which supports data sharing, information exchange and retrieval between two different standard formats. The proposed XML-based integrated medical information system will contribute to solve the problems of current medical information systems, by enabling integration of separated medical informations and by allowing data exchange and sharing through internet. The proposed system with XML is more robust than web-based medical information systems developed by using HTML, because XML itself provides more flexibility and extensibility than HTML.