• Korean Journal of Human Ecology
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• v.16 no.3
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• pp.505-522
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• 2007

This study examined the effects of eco-system factors on adolescents' suicidal ideation and whether self-esteem and depression mediate in the process to provide theoretical basis for prevention and treatment for problems of adolescents who have suicidal ideation. 2,088 high school students were asked to complete self-administering questionnaires on eco-system factors and adolescents' suicidal ideation. Data were analyzed with frequencies, t-test, ANOVA with Scheffe ad-hoc test, correlation analysis using SPSS 12.0 program and AMOS 5.0 program. Study results were ; First, adolescents' suicidal ideation showed significant differences according to their gender, socio-economic financial status, family structure, and the type of school they attended. Second, self-esteem and depression were proved to have significant mediating effect. Child abuse victimization, subjective school achievement and influence of media coverage of celebrity suicide were most important variables which influenced adolescents' suicidal ideation. These results reinforce importance of understanding adolescents' suicidal ideation with eco-system perspective. Moreover, prevention programs for adolescents' suicide require differentiated strategies and tactics according to the target group characteristics.

• Journal of East-West Nursing Research
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• v.23 no.2
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• pp.180-189
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• 2017

Purpose: This study was conducted to identify the perception of and attitude toward dementia and depression among residents in a community. Methods: Data were collected using the questionnaire from 226 residents in Incheon city from February to May, 2017. The data were analyzed using t-test, ANOVA and Scheffe's test to identify differences in perception of and attitude toward dementia and depression. Pearson correlation coefficients were used to identify the correlation between the study variables, and multiple regression was used to identify factors affecting depression. Results: There were significant differences in perception of dementia according to age, education, marital status, and exercise. Also, significant differences in attitude toward dementia were found in occupation, family history of dementia and education about dementia. Depression was significantly different depending on the type of health insurance coverage and alcohol drinking. The scores of perception of dementia and depression were 11.09, 2.37, respectively on a 2-point scale and for attitude toward dementia was 85.94 on a 7-point Likert scale. The perception of dementia was positively correlated with the attitude toward dementia and there were negative correlations between perception of dementia and age and between depression and attitude toward dementia. Conclusion: The results of this study suggest that we should improve perception of and attitude toward dementia and reduce depression to prevent and manage dementia effectively.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2226-2230
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• 2005

The Advanced Spent Fuel Conditioning Process (ACP), which is a pre-disposal treatment process for spent fuel is being developed at the Korea Atomic Energy Research Institute (KAERI). The ACP equipment is operated in an intense radiation field as well as in a high temperature. Thus, the equipment is designed in consideration of the remote handling and maintenance. This paper describes a Bridge Transported Bilateral Force-Reflecting Servo-Manipulator (BTSM) system, which is being developed to overcome the limitation of access that is a drawback of the mechanical Master-Slave Manipulators (MSMs), which are mounted on the ACP hot cell wall for the operation and the maintenance of the ACP equipment. The BTSM system was manufactured and temporally installed at the mockup to test its performance. The manufactured BTSM system will be installed at the ACP hot cell on June 2005 after the accomplishment of the performance test. The BTSM system consists of four components: a transporter with a telescoping tubeset, a slave manipulator, a master manipulator, and a remote control system. This system will highly increase the volume of coverage for the operation and maintenance of the ACP equipment.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.2
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• pp.71-81
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• 2014

Time synchronization system using dual frequency bands is designed and the error sources are analyzed for alternative synchronized-pseudolite navigation system (S-PNS) which aims at military application. To resolve near/far problem, dual frequency band operation is proposed instead of pulsing transmission which degrades level of reception. In dual frequency operation H/W delay should be considered to eliminate errors caused by inter-frequency bias (IFB) difference between the receivers of the pseudolites and users. When time synchronization is performed across the sea, multipath error is occurred severely since the elevation angle between pseudolites is low so total reflection can be happened. To investigate the difference of multipath effects according to location, pseudolites are set up coastal area and land area and performances are compared. The error source related with tropospheric delay is becoming dominant source as the coverage of the PNS is broadening. The tropospheric delay is measured by master pseudolite receiver directly using own pseudorange and slave pseudorange. Flight test is performed near coastal area using S-PNS equipped with developed time synchronization system and test results are also presented.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.66-71
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• 2009

In view of mutual complementary feature of wide coverage and high data rate, the interworking between 3G cellular network and WLAN is a global trend of wireless communications. This paper introduces the analytic result of an authentication mechanism for 3GPP-WLAN seamless mobility under the USIM-based authentication test-bed. In a handover process between heterogeneous networks, authentication is the main factor of handover delay. So authentication processing time should be firstly reduced. This paper describes an USTM-based EAP-AKA test-bed implemented for handover in UMTS and WLAN interworking systems. Experimental result has shown that the fast re-authentication mechanism during handover has reduced the handover delay by about 48.6%.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.122-128
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• 2017

Purpose: To investigate the corrosion inhibition effect of the natural spearmint oil extracted from Mentha Spicata plants on 304 stainless steel in different concentrations of hydrochloric acid. Method: The anti-corrosive effect has been investigated in 0.5m, 1m and 2m HCl using weight loss test and electrochemical polarization method as a function of inhibitor concentration and immersion time in strong chloride environment. The surface morphology was analysed by scanning electron microscopy (SEM). Results: The corrosion rate of steel decreased and inhibition efficiency increased with the increase in inhibitor concentration. Microscopic evaluation revealed significant corrosion in the specimens immersed in uninhibited conditions. Potentiodynamic polarization test results showed an increase in corrosion potential (Ecorr) and decrease in corrosion current (icorr) value with increasing concentration of inhibitor. Conclusions: Immersion of steel in higher concentration of inhibitor resulted in greater surface coverage value and hence lesser number of surface corrosion sites/pores were formed; thus lowering the corrosion rate.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.5
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• pp.47-55
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• 2005

This study was conducted to suggest revegetation character for environment factor of slope. Field test carried out for the man-made slope with three types(0.5cm no net, 3.0cm no net, 3.0cm net) revegetation methods in Hwaseong. Test revegetation plants were Festuca arundinacea, Lolium perenne, Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria M. The result of this study can be summarized as follows; 1. The soil hardness, the soil acidity, and the soil humidity of three types(0.5cm no net, 3.0cm no net, 3.0cm net) revegetation methods were at a suitable value for plants growth. 2. All plant growth index(seedling number, ground coverage, plant height, plant weight, etc) of south slope were better than north slope. But plant growth index of net plots were similar to no net plots. 3. For washout investigation, washout quantity of north slope was plentifully measured from south slope, and 1 amount of rainfall will be big was visible appears plentifully.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.1854-1860
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• 2014

In this paper, the energy saving on mobile communication repeater is studied. DB(Dual Band) small repeater, which is currently used in the field for indoor coverage, is adopted as a test unit. For reducing the power consumption, PFC (Power Factor Correction) is included on SMPS (Switching Mode Power Supply) of the DB small repeater. The test results show that approximately 38.9% of the power consumption is reduced comparing with the repeater without PFC. It means that approximately 230.43kWh per unit can be saved annually.

• Journal of IKEEE
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• v.19 no.2
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• pp.186-192
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• 2015

This paper proposes an automatic generation technology of test case based on API in source code for software's quality improvement. The proposed technology is comprised of four processes which are analyzing source code by using the Doxygen open source tool, defining API specification by using analyzed results, creating test design, generating a test case by adapting Pairwise test technology. Analyzing source code by using the Doxygen open source tool is the phase in which API information in source code such as the API name, input parameter and return parameter are extracted. Defined API specification by using analyzed results is the phase where API informations, which is needed to generate test case, are defined as a form of database by SQLite database on the basis of extracted API information. Creating test design is the phase in which the scenario is designed in order to be composed as database by defining threshold of input and return parameters and setting limitations based on the defined API. Generating a test case by adapting Pairwise test technique is the phase where real test cases are created and changed into database by adapting Pairwise technique on the base of test design information. To evaluate the efficiency of proposed technology, the research was conducted by begin compared to specification based test case creation. The result shows wider test coverage which means the more cases were created in the similar duration of time. The reduction of manpower and time for developing products is expected by changing the process of quality improving in software developing from man-powered handwork system into automatic test case generation based on API of source code.

• Aerospace Engineering and Technology
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• v.4 no.2
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• pp.1-6
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• 2005

In this study, the method to improve positioning accuracy under the multi-DGPS coverage is suggested. the linearly interpolated PRC regenerating algorithm was applied to improve the DGPS positioning accuracy at user's position by using the various PRC information obtained from multi-DGPS reference stations. To test the performance of the suggested method, the RTK-GPS result was used as the reference and the quantitative analysis results of the performance of the developed navigation algorithm are presented.