• Journal of Internet Computing and Services
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• v.12 no.1
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• pp.1-10
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• 2011

The spectrum sensing is one of the fundamental functions to realize the cognitive radios. One of problems in the spectrum sensing is that the performance of spectrum sensing can be degraded due to fading and shadowing. In order to overcome the problem, cooperative spectrum sensing method is proposed, which uses a distributed detection model and can increase sensing performance. However, the performance of cooperative spectrum sensing can be still affected by the interference factors such as obstacle and malicious user. Especially, most of cooperative spectrum sensing methods only considered the stationary primary user. In the ubiquitous environment, however the mobile primary users should be considered. In order to overcome the aforementioned problem, in this paper we propose a robust spectrum detection method based on localization where we estimate the location of the mobile primary user, and then based on the location and transmission range of primary user we detect interference users if there are, and then the local sensing reporting from detected interference users are excluded in the decision fusion process. Through simulation, it is shown that the sensing performance of the proposed scheme is more accurate than that of conventional other schemes

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.1
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• pp.1-14
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• 2023

This study is a leading case of empirical analysis of whether, when corporate stakeholders (government, investors, customers, managers, employees) put pressure on companies for ESG management, it affects the introduction and implementation of ESG activities (environmental, social, governance) and affects business performance. As for the research method, a sustainability report was published, and a web survey of Korea Research Inc. was conducted from May 10 to May 20, 2022 targeting ESG management managers of 192 companies, and analyzed through the PLS structural equation model. As a result of the study, it was found that the introduction and execution of ESG is closely influenced by the pressure from the government, investors, managers, and employees, and in particular, the internal pressure of current managers and executives and employees has a great impact on the introduction and implementation of environmental, social, and governance activities. In particular, although external pressure also has some influence, it is practical to suggest that strong internal pressure is necessary for continuous activities and performance. And, methodologically, the main activity indicators of the GRI Reporting Guidelines, which are the most representative ESG management indicators, were developed as a questionnaire, and reliability, validity, and model fit were secured through comparison with indicators of multiple systems and expert reviews. The limitations of this study are that more in-depth analysis by industry or size is possible when ESG management is mature and sufficient samples are secured, and complex ESG pressure factor modeling is possible when more diverse stakeholders are added.

• Korean Journal of Radiology
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• v.20 no.6
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• pp.880-893
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• 2019

Objective: To assess the technical performance of two-dimensional shear wave elastography (2D-SWE) for measuring liver stiffness. Materials and Methods: The Ovid-MEDLINE and EMBASE databases were searched for studies reporting the technical performance of 2D-SWE, including concerns with technical failures, unreliable measurements, interobserver reliability, and/or intraobserver reliability, published until June 30, 2018. The pooled proportion of technical failure and unreliable measurements was calculated using meta-analytic pooling via the random-effects model and inverse variance method for calculating weights. Subgroup analyses were performed to explore potential causes of heterogeneity. The pooled intraclass correlation coefficients (ICCs) for interobserver and intraobserver reliability were calculated using the Hedges-Olkin method with Fisher's Z transformation of the correlation coefficient. Results: The search yielded 34 articles. From 20 2D-SWE studies including 6196 patients, the pooled proportion of technical failure was 2.3% (95% confidence interval [CI], 1.3-3.9%). The pooled proportion of unreliable measurements from 20 studies including 6961 patients was 7.5% (95% CI, 4.7-11.7%). In the subgroup analyses, studies conducting more than three measurements showed fewer unreliable measurements than did those with three measurements or less, but no intergroup difference was found in technical failure. The pooled ICCs for interobserver reliability (from 10 studies including 517 patients) and intraobserver reliability (from 7 studies including 679 patients) were 0.87 (95% CI, 0.82-0.90) and 0.93 (95% CI, 0.89-0.95), respectively, suggesting good to excellent reliability. Conclusion: 2D-SWE shows good technical performance for assessing liver stiffness, with high technical success and reliability. Future studies should establish the quality criteria and optimal number of measurements.

• The Journal of Fisheries Business Administration
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• v.18 no.1
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• pp.37-57
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• 1987

This article discussed the characteristics of several Pareto-optimal incentive contracts between owner and labor, more specifically, four situations: reporting output jointly observable by labor ana owner; reporting both output and effort; incorporating other endogenous elements (like capital) that affect the production process and Pareto-optimal fee schedules; and ascertaining the effects of private pre-decision information private- decision information, and per-contact informational asymmetries. Also presented were several extensions of the basic contractual model, and the different components of agency costs associated with labor-owner contractual relations. In a single-period model, the agency problem exists because the uncertainty prevents the owner from using the cash flow to determine unambiguously the labor's action. Holmstrom(1979) suggests that "when the same situation repeats itself over time, the effects of uncertainty tend to be reduced and dystunctional behavior is more accurately revealed, thus alleviating the problem of moral hazard. " Under these conditions, if the labor selects the first-best level of effect in each period, the cash flow will be independent and identically distributed over time. As the number of periods increases, the variance of the labows average output, if he selects the first-best level of effort in each period, gets smaller. Note that for this diversification effect to occur, it is necessary that the owner evaluate the labor's effort over the entire history of his employment, rather than evaluate each period's performance separately. Radner(1980) and Rubinstein and Yaari(1980) consider the extreme case in which there are an infinite number of observations. They show that the owner can eventually detect and systematic shirking on the part of the labor by comparing the labor's average output with what would be expected if the labor had been selecting the first-best level of effort in each period. In a dynamic model with incentive problems we have demonstrated that the labor's second-period compensation will depend on his first-period performance. This allows the owner to diversify away some of the uncertainty surrounding the labor's actions. In addition, this allows the owner to smooth the labor's income over time by spreading the risk of the first-period outcome over both periods. At least some unexplored avenves in this area invite future accounting research: situations where owner has different incompatible objectives and negotiates a contract with labor; circumstances in which owner deals with multiple objectives and negotiates contracts with several labors simultaneously; the value of costly accounting information systems and communication in establishing, Pareto-optimal incentive contracts, and the value and effects of inside information, Thorough theoretical or empirical research on each of these topics not only would increase our knowledge about the role and significance of accounting information but could also provide explanations of the inherent differences among various organizations and in their economic behavior. behavior.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1100-1109
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• 2021

Objective: To compare the diagnostic performance between Prostate Imaging-Reporting and Data System version 2.0 (PI-RADSv2.0) and version 2.1 (PI-RADSv2.1) for clinically significant prostate cancer (csPCa) in the peripheral zone (PZ). Materials and Methods: This retrospective study included 317 patients who underwent multiparametric magnetic resonance imaging and targeted biopsy for PZ lesions. Definition of csPCa was International Society of Urologic Pathology grade ≥ 2 cancer. Area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for csPCa were analyzed by two readers. The cancer detection rate (CDR) for csPCa was investigated according to the PI-RADS categories. Results: AUC of PI-RADSv2.1 (0.856 and 0.858 for reader 1 and 2 respectively) was higher than that of PI-RADSv2.0 (0.795 and 0.747 for reader 1 and 2 respectively) (both p < 0.001). Sensitivity, specificity, PPV, NPV, and accuracy for PI-RADSv2.0 vs. PI-RADSv2.1 were 93.2% vs. 88.3% (p = 0.023), 52.8% vs. 76.6% (p < 0.001), 48.7% vs. 64.5% (p < 0.001), 94.2% vs. 93.2% (p = 0.504), and 65.9% vs. 80.4% (p < 0.001) for reader 1, and 96.1% vs. 92.2% (p = 0.046), 34.1% vs. 72.4% (p < 0.001), 41.3% vs. 61.7% (p < 0.001), 94.8% vs. 95.1% (p = 0.869), and 54.3% vs. 78.9% (p < 0.001) for reader 2, respectively. CDRs of PI-RADS categories 1-2, 3, 4, and 5 for PI-RADSv2.0 vs. PI-RADSv2.1 were 5.9% vs. 5.9%, 5.8% vs. 12.5%, 39.8% vs. 56.2%, and 88.9% vs. 88.9% for reader 1; and 4.5% vs. 4.1%, 6.1% vs. 11.1%, 32.5% vs. 53.4%, and 85.0% vs. 86.8% for reader 2, respectively. Conclusion: Our data demonstrated improved AUC, specificity, PPV, accuracy, and CDRs of category 3 or 4 of PI-RADSv2.1, but decreased sensitivity, compared with PI-RADSv2.0, for csPCa in PZ.

• Journal of Environmental Policy
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• v.9 no.3
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• pp.69-114
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• 2010

This study investigates the voluntary corporate disclosure of environmental information via stand-alone environmental reports or company web-sites. Quality of disclosure was assessed using the content analysis index proposed by Clarkson et al. (2008) based on GRI guidelines. Descriptive statistics on disclosure scores by category suggest that the level of disclosure is low relative to the expectation implied by the GRI reporting guidelines, and points to the need for improvement in the future. Specific areas where improvement is required include the disclosure of environmental performance indicators. Corporate environmental performance was measured in terms of the percentage of toxic wastes that was treated or processed by each firm and economic performance, by industry-adjusted annual return, which was subject to a series of association tests designed to explore the interrelations among environmental disclosure, environmental performance, and economic performance. The individual equation approach based on OLS procedures suggests a positive association between environmental performance and the level of discretionary environmental disclosures, which is not the case between environmental and economic performance. An integrated analysis using simultaneous equations approach does not indicate any significant relationships among three constructs, suggesting the lack of endogeneity, inconsistent with Al-Tuwaijri et al. (2004). Additional analysis assesses the level of environmental disclosure made in footnotes to the audited annual reports, which suggests that the quality of disclosure is very low and that footnote disclosure does not serve as a meaningful channel for the provision of corporate environmental information.

• Women's Health Nursing
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• v.5 no.3
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• pp.327-336
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• 1999

The purpose of this study was to identify the health promotion behavior and its related factors of persons who wanted a comprehensive health check-up in order to provide a basis for health education to promote health enhancing behavior. Study variables were induced from Pender's Health Promotion Model. The subjects were 160 persons who had a check-up at the health promotion center in a university hospital in Tae-Gu, between September 8 and 22, 1998. The following instruments were used in the study : Lee Tae Wha's Health Promoting Life-style Profile, Park Chai soon's Self-efficacy Instrument and Moon Jeong Soon's Perceived Benefit and Barrier Instrument. Data was collected by self-reporting questionnaire. Analysis of the data was done by SAS program, t-test, ANOVA and Pearson-Correlation Coefficient. The results of this study were as follows. 1. The average score for the health-promotion behavior was 104.64. In the subcategories, self-actualization showed the highest degree of performance and physical exercise showed the lowest degree of performance. 2. In the relation of general characteristics of subjects to the level of health-promoting behavior, the male, the married, the group with several symptoms showed a high level of health-promoting behavior. 3. The relationship between the degree of performance in health-promotion behavior and its correlates were as follows: Self-efficacy was positively correlated to health promotion behavior, while the perceived barrier was correlated negatively. But the perceived benefit did not show a significant correlation with health promotion behavior. Results suggest that the development of programs with strategies to strengthen doing physical exercise and concerning health, increase self-efficacy and exclude the barriers to health promotion is recommended to individuals seeking a comprehensive health check-up.

• Korean Journal of Health Education and Promotion
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• v.21 no.2
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• pp.1-16
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• 2004

The ultimate goal of health promotion programs is to improve the quality of life through promoting community health. Since the performance of health promotion programs are greatly affected by the quality of the planning and implementation process of the programs, the proper quality assessment of the program process is very important. According to existing literature, the tool for assessing the quality of the process and implementation as well as the outcome. However, no assessment tool for the quality of the process of health promotion programs has been developed in Korea. The purpose of the study is to develop a quality assessment tool for the process of health promotion programs being conducted at public health centers in Korea. The quality assessment tool developed in the study consists of the following four domains： strategic planning (14 items), program management (11 items), monitoring and evaluation (13 items), and resources and information (15 items). The strategic planning deals with the function of the planning staff and committees, community data analysis, the feasibility of the program, and the approach methods for attaining the goal of the program. The program management includes items on the qualification and power of the program staff. Monitoring and evaluation deals with the planning and education for monitoring, reporting and communication among program units, and feedback after monitoring. Finally, the resource and information covers the planning and activities for obtaining resources and information, community networking, beneficiaries' response, and consulting activity of the staff.

• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.387-392
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• 2011

Enzymes are being used in various fields due to their unique property of substrate specificity. Enzyme-linked immunosorbent assay(ELISA) has enabled the detection of various antigens by reporting the binding event of antigen and antibody via enzyme-catalyzed reaction. However, the sensitivity improvement of conventional ELISA has been limited because only one enzyme molecule is conjugated to one molecule of antibody. To overcome this limitation and further improve the sensitivity of ELISA, there have been efforts to increase the number ratio of enzymes to antibody. Recently, the nanobiocatalytic approaches, with their successful enzyme stabilization, improved the performance stability as well as sensitivity in a modified protocol of ELISA. The present paper introduces the basic principle of ELISA, and the recent efforts to improve sensitivity and performance stability of ELISA by using the nanobiocatalytic approaches.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.253-263
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• 2015

Lately, spectrum sensing performance has been improved by using cooperate spectrum sensing which each results of sensing of several secondary users are reported to the fusion center. Using Cognitive Radio, secondary user is able to share a bandwidth allocated to primary user. In this paper, we propose a new decentralized cooperative spectrum sensing scheme which compensates the performance degradation of existing decentralized cooperative spectrum sensing considering the error probability of the channel which sensed result of the secondary user is delivered to the fusion center in decentralized cooperative spectrum sensing. In addition, a sensing threshold optimization of minimizing the error probability of decentralized cooperative spectrum sensing is introduced by deriving the equation and the optimal sensing threshold has been confirmed to maximize the decentralized cooperative spectrum sensing performance.