• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.11
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• pp.2992-3007
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• 2012

Recently there has been an increasing interest in exploring the radio irregularity research problem in Wireless Sensor Networks (WSNs). Measurements on real test-beds provide insights and fundamental information for a radio irregularity model. In our previous work "LMAT", we solved the path planning problem of the mobile anchor node without taking into account the radio irregularity model. This paper further studies how the localization performance is affected by radio irregularity. There is high probability that unknown nodes cannot receive sufficient location messages under the radio irregularity model. Therefore, we dynamically adjust the anchor node's radio range to guarantee that all the unknown nodes can receive sufficient localization information. In order to improve localization accuracy, we propose a new 2-hop localization scheme. Furthermore, we point out the relationship between degree of irregularity (DOI) and communication distance, and the impact of radio irregularity on message receiving probability. Finally, simulations show that, compared with 1-hop localization scheme, the 2-hop localization scheme with the radio irregularity model reduces the average localization error by about 20.51%.

• Tunnel and Underground Space
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• v.19 no.1
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• pp.19-30
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• 2009

For the purpose of determining the thickness of concrete lining and detect of the cavity where may be located behind tunnel lining, IE (Impact-Echo) method it effectively useful in the tunnel safety diagnosis and the quality control during the construction. As a part of case study, we applied IE method to various tunnel structure types such as road tunnel and subway tunnel constructed by NATM (New Austrian Tunnelling Method) and ASSM (American Steel Support Method). As tunnel specifications estimated from this method were compared with coring data, design drawing and other survey results, it was very good agreement with each other. In conclusion, we verified that IE method shows an accurate and reliable result. The conventional interpretation of IE method in frequency domain gives only vertical information at a certain point. However, the interpretation using time-frequency analysis and depth section imaging technique from two dimensional profiling surveys can show more reliable information about structure inside.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.272-288
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• 1990

The uncertainty quantification process in probabilistic Risk Assessment usually involves a specification of the uncertainty in the input data and the propagation of this uncertainty to the final risk results. The distributional sensitivity analysis is to study the impact of the various assumptions made during the quantification of input parameter uncertainties on the final output uncertainty. The uncertainty importance of input parameters, in this case, should reflect the degree of changes in the whole output distribution and not just in a point estimate value. A measure of the uncertainty importance is proposed in the present paper. The measure is called the distributional sensitivity measure(DSM) and explicitly derived from the definition of the Kullback's discrimination information. The DSM is applied to three typical discrimination information. The DSM is applied to three typical cases of input distributional changes: 1) Uncertainty is completely eliminated, 2) Uncertainty range is increased by a factor of 10, and 3) Type of distribution is changed. For all three cases of application, the DSM-based importance ranking agrees very well with the observed changes of output distribution while other statistical parameters are shown to be insensitive.

• Journal of the Korean Society of Costume
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• v.54 no.6
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• pp.1-12
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• 2004

Price is one of the most important components of marketing mix. For consumers, price is an always-existing cue and definite evaluation criteria. However, information on price is meaningful only when it is perceived. Sources of price perception can be the actual retail price at the selling point, the internal reference price expected by consumers for a certain clothing product, and the external reference price advertised by marketer such as the price before mark-down. The purpose of this study was to investigate the influence of internal reference price on consumers' purchasing process of clothing products. A questionnaire including clothing stimuli was developed in order to assess consumers' internal reference price level. Usable data from 680 adult female urban residents were used for data analysis. Results indicated that consumers with relatively lower internal reference price tend to react low-price focused external reference price and use discount stores and unit price promotions. Consumers with relatively higher internal reference price advertisement are likely to have higher level of education, tend to infer price information to higher quality or prestige of products, and purchase clothing with regular retail price or coupons.

• Journal of Korea Technology Innovation Society
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• v.6 no.3
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• pp.328-344
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• 2003

This paper is aimed at analyzing the effect of Information Technology (IT) investment on the output growth and Total Factor Productivity (TFP) of Korean stock industry. Data on 24 stock firms for the eleven years (1991-2001) are used for the analysis. It is identified that there are both direct and indirect impacts of IT investment of the Korean stock industry on output growth. The total effect on output growth is 1.34 percentage point per year, which divided into a direct effect of investment in IT on the output growth is 1.97 and an indirect effect on the TFP is -0.63 percentage points per year. Results show that IT investment cannot contribute to increased stock industry productivity. Therefore, the Korean stock industry has not benefited from increased investment on IT in increasing productivity, implying the so-called productivity paradox has existed during the period.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.4
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• pp.77-86
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• 2008

The reliability of leaded and lead-free solders of BGA type packages on a printed circuit board was investigated by employing the standard drop test and 4-point bending test. Tested solder joints were examined by optical microscopy to identify associated failure mode. Three-dimensional finite element analysis(FEM) with ANSYS Workbench v.11 was carried out to understand the mechanical behavior of solder joints under the influence of bending or drop impact. The results of numerical analysis are in good agreement with those obtained by experiments. Packages in the center of the PCB experienced higher stress than those in the perimeter of the PCB. The solder joints located in the outermost comer of the package suffered from higher stress than those located in center region. In both drop and bending impact tests, the lead-free solder showed better performances than the leaded solders. The numerical analysis results indicated that stress and strain behavior of solder joint were dependent on various effective parameters.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.3
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• pp.41-61
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• 2004

The purpose of this paper is to construct $\ulcorner$CIDEAR(Cross Impact-DEA-AR)$\lrcorner$ model which evaluates proposed R&D projects considering cross impact among them and selects proper projects to utilize resources efficiently as well as to maximize efficacy of investments. For this purpose, $\ulcorner$CIDEAR$\lrcorner$ model is designed as the following six steps. $\ulcorner$Decision Theory Evaluation Model$\lrcorner$ is for setting and selecting the evaluation items according to the structured procedure of evaluation system. The priority of items is decided at $\ulcorner$AR Decision Model$\lrcorner$$\ulcorner$Cross Impact Estimation Model$\lrcorner$ is for computing the final probability of success and the result is used to revise the evaluation results of $\ulcorner$Decision Theory Evaluation Model$\lrcorner$. $\ulcorner$Resource Performance Analysis Model$\lrcorner$ classifies the proposed R&D projects on the basis of required resources and expected performance. Consequently, the possibility of bias of project selection can be prevented. $\ulcorner$Priority Oder Decision Model$\lrcorner$ is for computing the efficacy of proposed projects. Finally, $\ulcorner$Efficacy-Efficiency Cause Analysis Model$\lrcorner$ analyzes the structure of efficacy and efficiency of the projects. The major findings and significances of this study are summarized as follows: (1) $\ulcorner$CIDEAR$\lrcorner$ model can deal with the affairs of R&D projects having the characteristics of mutual independence as well as mutual dependence in the point of efficacy and efficiency. Hence, it is possible to evaluate and select R&D projects more accurately. (2) It can be possible to raise the possibility of projects success. R&D manager can use the information for project management because the efficacy-efficiency structure of selected projects can be analyzed. (3) We proved the usefulness of the constructed $\ulcorner$CIDEAR$\lrcorner$ model using an case about twenty-one R&D projects of a leading company of electronic industry in Korea.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.184-189
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• 2007

Concerns about food safety continue to rise and under this situation, governments of some countries have reinforced their regulations more strictly for food safety. In order to prevent food safety incidents or, at least to minimize the impact, the preparedness is very important. As a consequence of this, traceability system has become an essential tool for food safety. Recently, it requires more prevention-based food safety control system. One of the most generally used systems for food safety control is Hazard Analysis and Critical Control Point (HACCP). Both traceability and HACCP systems can be integrated through Electronic Product Code (EPC) Sensor Network technologies which have four value propositions. In this paper, we will introduce the concept of product and process traceability system (P2TS) through the integration of three systems to improve food safety management. The final aim is to find out the added values of the P2TS.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.873-884
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• 2021

People are often motivated by money. The salary a worker is paid by his employer can have a great influence on his performance in the administration. The study aims to identify and measure the impact of collective bargaining on the income of employees in enterprises. Participants were given a questionnaire consisting of 21 observation variables with a 5-point Likert scale. Independent variables were measured from 1 "without effect" to 5 "strongly". Based on the literature review and results of interviews, a total of 285 questionnaires were sent to participants in 95 enterprises in three typical fields: industry, construction, textile, and garment; 255 of them met the standards and were subject to be analyzed. We use qualitative research methods combined with quantitative research methods. SPSS20 software is used to synthesize and analyze data. The results of Cronbach's alpha, Exploratory Factor Analysis (EFA) and Multiple Regression Analysis (MRA) identify, the objective for collective bargaining (MT), time to organize collective bargaining (TD), the competence of the parties of the collective bargaining (NL), collective bargaining organization process (QT) are positively correlated with the income of workers in enterprises; information provided for collective bargaining (TT) has a negative correlation with the income of employees in enterprises. Based on the findings, some suggestions have been given for collective bargaining to increase the income of employees in enterprises in Vietnam.

• Korean Journal of Remote Sensing
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• v.33 no.4
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• pp.445-454
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• 2017

The performance of spatial downscaling models depends on the quality of input coarse scale products. Thus, the impact of intrinsic errors contained in coarse scale satellite products on predictive performance should be properly assessed in parallel with the development of advanced downscaling models. Such an assessment is the main objective of this paper. Based on a synthetic satellite precipitation product at a coarse scale generated from rain gauge data, two synthetic precipitation products with different amounts of error were generated and used as inputs for spatial downscaling. Geographically weighted regression, which typically has very high explanatory power, was selected as the trend component estimation model, and area-to-point kriging was applied for residual correction in the spatial downscaling experiment. When errors in the coarse scale product were greater, the trend component estimates were much more susceptible to errors. But residual correction could reduce the impact of the erroneous trend component estimates, which improved the predictive performance. However, residual correction could not improve predictive performance significantly when substantial errors were contained in the input coarse scale data. Therefore, the development of advanced spatial downscaling models should be focused on correction of intrinsic errors in the coarse scale satellite product if a priori error information could be available, rather than on the application of advanced regression models with high explanatory power.