• Title/Summary/Keyword: reliability factors

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Detection and Measurement of Nuclear Medicine Workers' Internal Radioactive Contamination (핵의학과 종사자의 방사성동위원소 체내오염 측정)

  • Jeong, Gyu-Hwan;Kim, Yong-Jae;Jang, Jeong-Chan;Lee, Jai-Ki
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.123-131
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    • 2009
  • Purpose: We tested a sample of nuclear medicine workers at Korean healthcare institutions for internal contamination with radioactive isotopes, measuring concentrations and evaluating doses of individual exposure. Materials and Methods: The detection and measurement was performed on urine samples collected from 25 nuclear medicine workers at three large hospitals located in Seoul. Urine samples were collected once a week, 100~200 mL samples were gathered up to 6~10 times weekly. A high-purity germanium detector was used to measure gamma radiations in urine samples for the presence of radioactive isotopes. Based on the detection results, we estimated the amounts of intake and committed effective doses using IMBA software. In cases where committed effective doses could not be adequately evaluated with IMBA software, we estimated individual committed effective doses for radionuclides with a very short half life such as $^{99m}Tc$ and $^{123}I$, using the methods recommended by International Atomic Energy Agency. Results: Radionuclides detected through the analysis of urine samples included $^{99m}Tc$, $^{123}I$, $^{131}I$ and $^{201}Tl$, as well as $^{18}F$, a nuclide used in Positron Emission Tomography examinations. The committed effective doses, calculated based on the radionuclide concentrations in urine samples, ranged from 0 to 5 mSv, but were, in the majority of cases, less than 1 mSv. The committed effective dose exceeded 1 mSv in three of the samples, and all three were workers directly handling radioactive sources. No nurses were found to have a committed effective dose in excess of 1 mSv. Conclusions: To improve the accuracy of results, it may be necessary to conduct a long-term study, performed over a time span wide enough to allow the clear determination of the influence of seasonal factors. A larger sample should also help increase the reliability of results. However, as most Korean nuclear medicine workers are currently not necessary to monitored routinely for internal contamination with radionuclides. Notwithstanding, a continuous effort is recommended to reduce any unnecessary exposure to radioactive substances, even if in inconsequential amounts, by regularly surveying workplace environments and frequently monitoring atmospheric concentrations of radionuclides.

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Development of the Perceived Stress Response Inventory (스트레스반응 지각척도의 개발)

  • Koh, Kyung-Bong;Park, Joong-Kyu;Kim, Chan-Hyung
    • Korean Journal of Psychosomatic Medicine
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    • v.7 no.1
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    • pp.26-41
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    • 1999
  • The perceived stress response inventory(PSRI) was developed to measure 4 types of current stress responses : emotional, somatic, cognitive, and behavioral responses. 242 patients with psychiatric disorders(71 patients with anxiety disorders, 73 patients with depressive disorders, 47 patients with somatoform disorders, 51 patients with psychosomatic disorders) and 215 healthy subjects completed the questionnaire including the PSRI. Global assessment of recent stress(GARS) scale, perceived stress questionnaire(PSQ) and symptom checklist-90-revised(SCL-90-R) were also administered at the same time. Factor analysis for each of 4 types of stress responses yielded 8 factors : negative emotional responses, general somatic symptoms, specific somatic symptoms, lowered cognitive function and general negative thinking, self-depreciative thinking, impulsive-aggressive thinking, passive-responsive and careless behavior, and impulsive-aggressive behavior. Both test-restest reliability(r= .83 -.93) and internal consistency(Cronbach's alpha : .79 -.96 for each of 8 subscales and .98 for total items of the scale) were all at statistically significant levels. Total scores of the PSRI significantly correlated with total scores of GARS scale, PSQ, and global indicies of SCL-90-R, respectively. The patient group had significantly higher scores than healthy subjects in each of all the subscales except impulsive-aggressive behavior subscale. These results suggest that the PSRI is a reliable and valid tool stable over time which may be effectively used for the research in stress-related field including psychosomatic medicine.

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The Trend Analysis of Propulsion System for Railway Vehicle Using Patent Analysis (특허분석을 통한 철도차량용 추진제어장치 기술 분석)

  • Han, Young-Jae;Lee, Su-Gil;Park, Chan-Kyoung;Kim, Young-Guk;Bae, Chang-Han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.131-138
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    • 2018
  • In this study, we investigated the trend of technological development in major countries related to the propulsion equipment of railway vehicles. The propulsion system is the main equipment of electric vehicles. A lot of time and investment are required in order to ensure the development of technology. Therefore, developed countries have maximized their effort to develop technologies with safety, reliability, and convenience of maintenance. They have also done their utmost to prevent technology transfer to other countries after the development of new technologies. For example, Toshiba of Japan developed a new 3,300V/1,500 A class IGBT power device, but was reluctant to export it to foreign countries in order to protect this technology. In this study, we analyzed the patents applied for related to propulsion control systems and presented the direction of development during the technical development of these systems. The patent analysis of the core technologies was conducted using the Thomson Innovation DB. We examined the number of patents applied for by country, year and major applicant. As a result of the analysis, it was found that the proportion of patent applications per country was in the order of China, 48%, Europe 16.6%, and the United States 14.9%. The patent situation of the top 10 principal applicants revealed that (the top three were?) ABB 14%, GE 13%, and CRRC 12%. At the same time, we also conducted a qualitative analysis of the level of technical development by evaluating such factors as the influence index, quotation, market securing power and citation. Based on the result of the patent analysis, we presented the direction of technical development of the propulsion control equipment of railway vehicles. Based on the analysis results, it was found that domestic applicants considerably reduced their efforts to protect their patents from foreign companies. Nowadays, most of the electric motors used in Korea are induction motors. In advanced countries, permanent magnet electric motors are employed in new railway lines. Therefore, intensive investment is needed in new developments.

An Efficient Estimation of Place Brand Image Power Based on Text Mining Technology (텍스트마이닝 기반의 효율적인 장소 브랜드 이미지 강도 측정 방법)

  • Choi, Sukjae;Jeon, Jongshik;Subrata, Biswas;Kwon, Ohbyung
    • Journal of Intelligence and Information Systems
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    • v.21 no.2
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    • pp.113-129
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    • 2015
  • Location branding is a very important income making activity, by giving special meanings to a specific location while producing identity and communal value which are based around the understanding of a place's location branding concept methodology. Many other areas, such as marketing, architecture, and city construction, exert an influence creating an impressive brand image. A place brand which shows great recognition to both native people of S. Korea and foreigners creates significant economic effects. There has been research on creating a strategically and detailed place brand image, and the representative research has been carried out by Anholt who surveyed two million people from 50 different countries. However, the investigation, including survey research, required a great deal of effort from the workforce and required significant expense. As a result, there is a need to make more affordable, objective and effective research methods. The purpose of this paper is to find a way to measure the intensity of the image of the brand objective and at a low cost through text mining purposes. The proposed method extracts the keyword and the factors constructing the location brand image from the related web documents. In this way, we can measure the brand image intensity of the specific location. The performance of the proposed methodology was verified through comparison with Anholt's 50 city image consistency index ranking around the world. Four methods are applied to the test. First, RNADOM method artificially ranks the cities included in the experiment. HUMAN method firstly makes a questionnaire and selects 9 volunteers who are well acquainted with brand management and at the same time cities to evaluate. Then they are requested to rank the cities and compared with the Anholt's evaluation results. TM method applies the proposed method to evaluate the cities with all evaluation criteria. TM-LEARN, which is the extended method of TM, selects significant evaluation items from the items in every criterion. Then the method evaluates the cities with all selected evaluation criteria. RMSE is used to as a metric to compare the evaluation results. Experimental results suggested by this paper's methodology are as follows: Firstly, compared to the evaluation method that targets ordinary people, this method appeared to be more accurate. Secondly, compared to the traditional survey method, the time and the cost are much less because in this research we used automated means. Thirdly, this proposed methodology is very timely because it can be evaluated from time to time. Fourthly, compared to Anholt's method which evaluated only for an already specified city, this proposed methodology is applicable to any location. Finally, this proposed methodology has a relatively high objectivity because our research was conducted based on open source data. As a result, our city image evaluation text mining approach has found validity in terms of accuracy, cost-effectiveness, timeliness, scalability, and reliability. The proposed method provides managers with clear guidelines regarding brand management in public and private sectors. As public sectors such as local officers, the proposed method could be used to formulate strategies and enhance the image of their places in an efficient manner. Rather than conducting heavy questionnaires, the local officers could monitor the current place image very shortly a priori, than may make decisions to go over the formal place image test only if the evaluation results from the proposed method are not ordinary no matter what the results indicate opportunity or threat to the place. Moreover, with co-using the morphological analysis, extracting meaningful facets of place brand from text, sentiment analysis and more with the proposed method, marketing strategy planners or civil engineering professionals may obtain deeper and more abundant insights for better place rand images. In the future, a prototype system will be implemented to show the feasibility of the idea proposed in this paper.

The influences of sustainability management at institutional foodservice on store image and behavioral intention (소비자가 인식하는 산업체 급식업체의 지속가능경영활동이 점포이미지와 행동의도에 미치는 영향)

  • Ahn, Jiyoon;Seo, Sunhee
    • Journal of Nutrition and Health
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    • v.48 no.2
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    • pp.199-210
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    • 2015
  • Purpose: The purpose of this study was to determine the influence of sustainability management in institutional foodservice on store image and behavioral intention (revisit intention, word of mouth, willingness to pay a premium). Methods: Based on a total of 371 samples obtained from the empirical research, this study reviewed the reliability and fitness of the model. Results: According to results of exploratory factor analysis, sustainability management derived three factors, economic value, socially responsible, and environmentally sound. The structural equation modeling showed that social responsibility in sustainability management had a significant positive effect on store image and behavioral intention. In addition, customer's perceived store image in foodservice had a significant positive effect on behavioral intention. The relationship between sustainability management and behavioral intention was found to be a partially significant effect. Conclusion: The results of this study revealed the importance of sustainability management of foodservice to improve store image and behavioral intention.

A Study on Requirement and Degree of the Satisfaction about Cosmeceuticals of Women (우리나라 여성들의 기능성화장품에 대한 요구 및 만족도 연구)

  • Kim Kang-Mi;Kim Ju-Duck
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.4 s.48
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    • pp.571-582
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    • 2004
  • Recently the well-being, which is regarded as the new cultural code, has brought a new change in the cosmetic industry. The application of the functional products is getting mere and lots of functional cosmetics are now diversifying from the skin-care into the make-up as well as the herbal products. So the future in the market of functional cosmetic products is prospected to be positive. Therefore, cosmetic companies need an approach bases on the concept of the well-being. So to speak, they need to understand the needs of customers accurately from the customers point of view. Also it is a crucial issue that how the unique characteristics of functional cosmetic products as well as the development of products base on the concept of well-being make in balance. In this study, we attempt to inspect the advanced domestic market of the functional products due to the well-being trend and try to propose an option of making an advance it through the customers survey (for example, their need and their satisfaction on the functional products, etc) on the functional cosmetic products. For this purpose, it has been surveyed on adult female customers aged 19 to 60 located in Seoul and Gyeonggi province. 379 questionnaires among 510 were used in the final analysis. Collected data was analyzed using the statistical package for the social science (SPSS) program that can give the information about the general characteristics of the subjects like the frequency and percentage. And we used Cronbach's u reliability test, $x^2\;(chi-square)$ frequency analysis, t-test, and one-wat ANOVA to investigate the customers need, their degree of the satisfaction on the functional products of their own, factors of their perception on the quality on them. We think that the results of our study can act not only as the fundamental data on the customers need, their usage pattern, and their degree of the satisfaction, but also as the important tips of planning the marketing strategies.

A Study on Load-carrying Capacity Design Criteria of Jack-up Rigs under Environmental Loading Conditions (환경하중을 고려한 Jack-up rig의 내하력 설계 기준에 대한 연구)

  • Park, Joo Shin;Ha, Yeon Chul;Seo, Jung Kwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.1
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    • pp.103-113
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    • 2020
  • Jack-up drilling rigs are widely used in the offshore oil and gas exploration industry. Although originally designed for use in shallow waters, trends in the energy industry have led to a growing demand for their use in deep sea and harsh environmental conditions. To extend the operating range of jack-up units, their design must be based on reliable analysis while eliminating excessive conservatism. In current industrial practice, jack-up drilling rigs are designed using the working(or allowable) stress design (WSD) method. Recently, classifications have been developed for specific regulations based on the load and resistance factor design (LRFD) method, which emphasises the reliability of the methods. This statistical method utilises the concept of limit state design and uses factored loads and resistance factors to account for uncertainly in the loads and computed strength of the leg components in a jack-up drilling rig. The key differences between the LRFD method and the WSD method must be identified to enable appropriate use of the LRFD method for designing jack-up rigs. Therefore, the aim of this study is to compare and quantitatively investigate the differences between actual jack-up lattice leg structures, which are designed by the WSD and LRFD methods, and subject to different environmental load-to-dead-load ratios, thereby delineating the load-to-capacity ratios of rigs designed using theses methods under these different enviromental conditions. The comparative results are significantly advantageous in the leg design of jack-up rigs, and determine that the jack-up rigs designed using the WSD and LRFD methods with UC values differ by approximately 31 % with respect to the API-RP code basis. It can be observed that the LRFD design method is more advantageous to structure optimization compared to the WSD method.

A Study on the Analysis of Difference between IT and Non-IT Companies on the Smart Work Environment Continuous Use Intention - Focusing on Korean Small and Medium Enterprises (스마트워크 환경에서 지속사용의도에 대하여 IT기업과 비IT기업 간의 차이분석에 관한 연구 -한국 중소기업을 중심으로)

  • Jung, Soo-Yong;Shin, Yong-tae
    • Journal of Digital Convergence
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    • v.16 no.3
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    • pp.249-259
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    • 2018
  • This research had intended to find out regarding the present influences of the Smart Work on the intention to use continuously with the staff members working in the small- and medium-sized enterprises as the subject. And, finally, it had intended to find out about the Smart Work environments of the IT corporations and the non-IT corporations. For this research, the questionnaire survey data were collected from the staff members working at the small- and medium-sized enterprises. Through the questionnaire survey data that were collected, an empirical analysis was carried out. And, through the reliability analysis, the feasibility analysis, the discriminatory feasibility analysis, and the inspection of the degree of suitableness of the structural equation model, finally, the research model was verified and, finally, a difference analysis of the IT corporations and the non-IT corporations was carried out. Regarding the results of the analysis of the research, it appeared that the factors of the job efficiency and the job autonomy of the special characteristics of the job had the positive influences on the usefulness and the job satisfaction, which were the parameters and which were perceived. And it appeared that the time flexibility of the job form could not have any influences on the usefulness and the job satisfaction, which were the parameters and which were perceived. And it appeared that the spatial flexibility had the influences on the job satisfaction only. The perceived usefulness, which was a parameter, had the positive influences on the job satisfaction and the intention to use continuously. And, finally, the job satisfaction had the positive influences on the intention to use continuously. And it appeared that there were the differences, too, between the IT corporations and the non-IT corporations. It is thought that, through the results of this research and through the Smart Work environment, the positive influences on the workers and the organizations could be induced and that a better working environment than previously can be provided to the workers to fit the special characteristics of the corporations.

Economic Analysis of the Livestock Manure Treatment System Using Life-Cycle Cost Technique (LCC 기법을 통한 가축분뇨처리시설의 경제성 분석)

  • Kim, J.H.;Cho, S.H.;Kwag, J.H.;Choi, D.Y.;Jeong, K.H.;Chung, U.S.;Chung, M.S.;Park, S.K.
    • Journal of Animal Environmental Science
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    • v.17 no.sup
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    • pp.61-68
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    • 2011
  • To assess the total cost with all stages of facilities, the feasibility of Life Cycle Cost (LCC) analysis was examined in this study to estimate the livestock manure treatment system and optimal decision making process. For the economic evaluation, the plant/equipment investment and annual operation cost of four Public Livestock Recycling Facilities, whose treatment capacity is 100 ton piggery manure per day, was compared. The initial cost was in the range of 2,699 million won to 3,202 million won, where T and E methods were highest and lowest, respectively. The annual operation cost was in the level of 378 million to 498 million won, which decreased in the following order : T method > J method > E method > B method. For the LCC analysis, 4.7% of interest rate, 3.13% of inflation rate, and 1.52% of net discount rate was considered by the data received from Bank of Korea and Statics Korea in the period of 2000 to 2009. Also, for the calculation of present value factor, the durable years of civil engineering & construction, machinery and electric instrument was 30 years, 10 years and 15 years, respectively. Based on these consideration, operation cost was in the range of 17,570 won/ton to 20,661 won/ton, and E method (17,570 won/ton) was economical and B method (20,661 won/ton) was non-economical. Though initial cost of T method was higher than that of B method, LCC analysis of T method was lower than that of T method due to the lower operation cost. Therefore, LCC analysis, which considers both initial cost and operation cost, is more reasonable evaluation method than either initial cost or annual operation cost. For the change of LCC analysis according to the uncertainty, the sensitivity analysis was carried out using fluctuation magnitude of discount rate in the period of 2000 to 2009. As a result, LCC analysis evaluated by discount rate was stable for the uncertain factors since the cost leadership did not change even though the sensitivity analysis varied. In summary, the economic evaluation using LCC analysis could be an efficient reference to choose the suitable livestock manure treatment plants. Furthermore, standardization of statement calculation for the actual cost analysis should be conducted and more detailed study is necessary to validate this summary. Therefore, the application of comprehensive technology evaluation, which considers LCC analysis, should contribute in obtaining objectivity and enhancing reliability for the 'Evaluation of Livestock Manure Treatment System and its Technology'.

Study on Labeling Efficiency of $^{99m}Tc$-HMPAO ($^{99m}Tc$-HMPAO 표지효율에 대한 고찰)

  • Hyeon, Jun Ho;Lim, Hyeon Jin;Kim, Ha Kyun;Cho, Seong Uk;Kim, Jin Eui
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.2
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    • pp.131-134
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    • 2012
  • Purpose : The labeling efficiency of radiopharmaceuticals in nuclear medicine is important in terms of accuracy and reliability of the examination. Usually $^{99m}Tc$-HMPAO used for brain SPECT scan is chemically unstable since lots of impurities are existing. Therefore, occurrence of loss of labeling efficiency is easy to appear. In this paper, labeling and use of $^{99m}Tc$-HMPAO should be helpful through experiments on factors affecting the labeling efficiency of $^{99m}Tc$-HMPAO. Materials and Methods : Domestic HMPAO vials (Dong-A) used for brain SPECT scan were tested. Domestic Samyeong Generator 55.5 GBq (1,500 mCi), TLC measurement sets (ITLC-SG, butanone, saline, TLC chamber) and radio-TLC scanner (Advantest, Bioscan) were used. In the first experiment, after eluting generator at 1, 8, 16, 24, 28 hours apart, each eluted $^{99m}Tc$-pertechnetate were labeled with HMPAO and the labeling efficiency was measured. In the second experiment, after eluting $^{99m}Tc$-pertechnetate from a generator, $^{99m}Tc$-pertechnetate was drawn at 0, 1, 3, 6 hours. And each drawn $^{99m}Tc$-pertechnetate were labeled with HMPAO for measuring labeling efficiency. In the third experiment, labeling efficiency was measured at 0, 0.5, 3, 5, 7 hours after labeling $^{99m}Tc$-HMPAO. Results : In the first experiment, measured values were appeared 95.05, 94.64, 94.94, 95.64, 96.76% in passing order of time. In the second experiment, measured values were appeared 94.38, 94.23, 93.26, 91.03% in passing order of time. In the third experiment, measured values were appeared 95.76, 94.17, 88.19, 83.6, 76.86% in passing order of time. Conclusion : In the first experiment of this paper, labeling efficiency of $^{99m}Tc$-HMPAO labeled with $^{99m}Tc$-pertechnetate eluted after 24 hours from first elution. Additional experiments will be needed to discuss for usability. In the second experiment, the labeling efficiency was slightly decreased in chronological order, but it was measured higher than 90%. Also, additional experiments will be needed to discuss for usability. In the third experiment, the labeling efficiency was decreased considerably. Especially, within 3 hours after the labeling is recommended to use $^{99m}Tc$-HMPAO

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