• Journal of Labour Economics
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• v.37 no.1
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• pp.29-57
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• 2014

Using unemployment insurance and income-contingent loan (ICL) that conditions repayment by debtors upon their incomes this paper characterizes an efficient income support system for the unemployed, which maximizes their lifetime utilities by effectively enhancing inter-state and inter-temporal consumption-smoothing subject to incentive constraints on the part of the beneficiaries. This paper also emphasizes the generality of the argument for a mix of ICL and subsidy that may be applied potentially to many types of government welfare program.

• Physical Therapy Korea
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• v.2 no.2
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• pp.46-55
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• 1995

The purpose of this study was to assess the concurrent validity and reliability of goniometric measurement of joint motion. Subjects were 40 healthy university students. Measurements were performed by 4 inexperienced physical therapy students. Four different instruments were used and three readings were taken with each instrument in random order making a total of 12 readings for flexion of the right elbow of each subject. Goniometers used were 1. universal 2. fluid-based goniometer/inclinometer 3. digital LCD goniometer 4. electronic goniometer/torsiometer. The results were as follows: Concurrent validity was highest (r= .94) with the universal and digital LCD tools. Interrater reliability (Pearson Product Moment Correlation) was good for each tool. Interrater reliability calculated by ICC(2,1) was highest (.96) with the tensiometer and lowest (.78) with the digital LCD goniometer. Intrarater reliability calculated by ICC was excellent (${\geq}.90$) for all instruments. These results show that concurrent validity, intrarater and interrater reliability are very good in the used of all four types of goniometers/inclinometer/tensiometer, even with inexperienced raters. These results confirm the almost universal reliance on hand held goniometers for joint measurement by physical therapists as being a reliable practice. Further research should be done clinically with actual patients.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.4
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• pp.240-246
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• 2013

In heterogeneous networks, the almost blank subframes (ABS) for inter-cell interference coordination (ICIC), which can be protected from the CCI due to unutilized subframes (i.e., ABS) is proposed. However, the analytical model for ABS-based systems has not been fully studied yet. In this paper, we derive a new analytical model to evaluate the performance of ABS-based systems. In an analytic model, we assume that each carrier in multicarrier systems, such as in OFDMA, is subject to large-scale fading, which is independent of other carriers. As a performance measure, we present the cumulative distribution function (CDF) for the effective SINR. We show the accuracy of the analytical model via simulation results.

• Journal of Korean Elementary Science Education
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• v.39 no.3
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• pp.412-432
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• 2020

The purpose of this study is to explore the characteristics and the level of fourth grade elementary students' system thinking when they learn the unit of "Journey of Water" in terms of four key elements of system thinking such as understanding of the structure of a system, non-linearity and cyclic features, inter-relations and feedback between system properties, and temporal and invisible aspects of a system. Data included students' worksheets and their responses to a set of Likert-scaled and written assessment items on water cycle. The results showed that the level of students' system thinking did not have any hierarchy in relation to the key elements of water cycle system. In addition, the aspects of individual student's system thinking on its sub-elements were different from each other. Also, there were core ideas of system thinking which were intensively considered according to a given context to understand a complex systemic subject. When students learn water cycle, understanding of non-linearity and inter-relations were weaker compared with other key elements of system thinking. Therefore, if these two factors are taught in advance, it can promote understanding of whole system of water cycle.

• Journal of the Korean Home Economics Association
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• v.39 no.11
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• pp.175-192
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• 2001

This study investigated the relationships between inter-cultural experience and socio-psychological adjustment to the current life among children who have refilmed from living abroad. The subject of research consisted of 102 boys and 110 girls from fourth grade through sixth grade who returned to their home country after living in a foreign correlation Data were collected from 5 elementary schools in Seoul. Descriptive statistics, t-tests, correlation analysis and regression were used for data analysis. The results of children's social-psychological adjustment were represented by 3 categories: school/friend relationship, stress/strain and language/learning. The following are the summarized results; First, girl students were more likely to adapt to school/friend relationships in Korea and had lower stress/strain than boys. Second, the children having shorter period of residence in foreign county, lower adaptation ability to different culture and extrovert personality showed higher socio-psychological adjustments after returning to Korea. Third, the adjustment to school/friends was influenced by period of residency in the foreign county, the experience of different culture, and extrovert personality. The experience of different culture and extrovert personality effected stress/strain, and the adjustments to language/learning were influenced only by the ewperiecne of different culture. Lastly, the experience of different culture was the most important variable influencing all 3 categories of socio-psychological adjustments.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1616-1625
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• 2019

Measuring occurrence times of random events, aimed to determine the statistical properties of the governing stochastic process, is a basic topic in science and engineering, and has been the subject of numerous mathematical modeling approaches. Often, true statistical properties deviate from measured properties due to the so called dead time phenomenon, where for a certain time period following detection, the detection system is not operational. Understanding the dead time effect is especially important in radiation measurements, often characterized by high count rates and a non-reducible detector dead time (originating in the physics of particle detection). The effect of dead time can be interpreted as a suitable rarefied sequence of the original time sequence. This paper provides a limit theorem for a high rate (diffusion-scale) counter with extendable (Type II) dead time, where the underlying counting process is a renewal process with finite second moment for the inter-event distribution. The results are very general, in the sense that they refer to a general inter arrival time and a random dead time with general distribution. Following the theoretical results, we will demonstrate the applicability of the results in three applications: serially connected components, multiplicity counting and measurements of aerosol spatial distribution.

• Earthquakes and Structures
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• v.26 no.6
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• pp.463-475
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• 2024

The study aims to investigate the pounding that occurs between the isolator's ring and slider of isolated structures resulting from excessive seismic excitation, while considering soil-structure interaction. The dynamic responses and poundings of structures subjected a series seismic records were comparatively analyzed for three different soil types and fixed-base structures. A series of parametric studies were conducted to thoroughly discuss the effects of the impact displacement ratio, the FPB friction coefficient ratio, and the radius ratio on the structural dynamic response when considering impact and SSI. It was found that the pounding is extremely brief, with an exceptionally large pounding force generated by impact, resulting in significant acceleration pulse. The acceleration and inter-story shear force of the structure experiencing pounding were greater than those without considering pounding. Sudden changes in the inter-story shear force between the first and second floors of the structure were also observed. The dynamic response of structures in soft ground was significantly lower than that of structures in other ground conditions under the same conditions, regardless of the earthquake wave exciting the structure. When the structure is influenced by pulse-type earthquake records, its dynamic response exhibits a trend of first intensifying and then weakening as the equivalent radius ratio and friction coefficient ratio increase. However, it increases with an increase in the pounding displacement ratio, equivalent radius ratio, friction coefficient ratio, and displacement ratio when the structures are subjected to non-pulse-type seismic record.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.2
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• pp.40-43
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• 2015

In this paper, the effects of the leading and the following sounds with single frequency on sound localization are investigated. The sounds with different levels and ISIs(Inter Stimuli Intervals) were used. The width of test sound is 2ms, and those of the leading and the following sounds are 10ms. 1 kHz of the test sound is utilized. The arrival time difference in the subject's ears is set to be 0.5ms. The four kinds of level differences used for one ISI are 0, -10, -15, and -20dB interval. The leading sound is found to have more effect on sound localization than the following sound is. The effect of the leading sound is also found to be dependent on the value of ISI. When the value of the ISI is small, different effects affecting the sound localization are observed.

• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.311-314
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• 2015

Purpose: This study attempted to determine intra-rater reliability and inter-rater reliability for measurement of foot form using the FPI-6 (Foot Posture Index) in patients with hemiplegia caused by stroke. Methods: Twenty two stroke patients were recruited into the research and their foot posture was evaluated using the FPI. Two raters assessed 6 items sequentially in accordance with the FPI-6 manual. This procedure involved asking the subject to take several steps in-place, prior to settling into a comfortable stance position with double limb support. Subjects were instructed to stand still with their arms by their sides and look straight ahead. FPI-6 values ranged from -2 to +2 for each of the six criteria and from -12 to +12 for the total score, indicating a position for each foot either along the supinated (negative score) to pronated (more than +6) continuum of foot posture. Results: The results showed that intra-rater reliability and inter-rater reliability for a total FPI-6 score was high: 0.807-0.888. An almost perfect agreement between the two raters was identified in the foot's morphological classification (Somer's D=0.712; p<0.05). Intra-percentage agreement was high (88.6%). Conclusion: The FPI-6 is a quick, simple, and reliable clinical tool with demonstrated good to excellent intra-rater reliability and good inter-rater reliability when used in assessment of the stroke patient's foot.

• Journal of Trauma and Injury
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• v.28 no.3
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• pp.108-114
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• 2015

Purpose: To improve outcome of severe trauma patient, the shortening of transport time is needed. Although helicopter emergency medical services (HEMS) is still a subject of debate, it must also be considered for trauma system. The aim of this study is to assess whether transport method (HEMS versus ground EMS) is associated with outcome among inter-hospital transport. Methods: All trauma patients transported to regional emergency center by either HEMS or ground EMS from September 2011 to September 2014. We have classified patients according to two groups by transport method. Age younger than 15 years and self-discharged patients were excluded. Results: A total of 427 patients were available for analysis during this period. 60 patients were transported by HEMS and 367 patients were transported by ground EMS. HEMS group had higher mortality than ground EMS group (23.3% vs 3.5%; p<0.001), and included more patients with excess mortality ratio adjusted injury severity score (EMR-ISS) above 25 (91.7% vs 48.8%; p<0.001). In the multivariable regression analysis, HEMS was not associated with improved outcome compared with ground EMS, but only EMR-ISS was associated with a mortality of patients (odds ratio, 1.06; 95% confidence interval, 1.04-1.09). Conclusion: In this study, helicopter emergency medical services transport was not associated with a decreased of mortality among the trauma patients who inter-hospital transported to the regional emergency center.