• Journal of the Korean Society of Safety
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• v.15 no.4
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• pp.35-40
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• 2000

The influence of cyclic loading history on the creep behavior of the 30 vol% hot-pressed $SiC_f/Si_3N_4copmposite was experimentally investigated at $1200^{\circ}C$. The duration of loading/unloading had great effects on the creep behaviors. The short term duration cyclic loading history test results showed significant reduction in the primary and steady-state creep rates. For example, 300sec loading/300sec unloading history resulted in 70% lower steady-state creep rate than that of the continuous loading. However the long term duration cyclic loading history test results showed little change in creep rates compared to those of the continuous one. The reason for the significant change in the short term duration cycles was estimated due to the change in the stress redistribution between the fiber and matrix during the creep recovery in the primary stage.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.97-108
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• 2019

In a situation where production of short-term income forestry products has been stagnant or decreased in recent years, the government or related agencies are trying to promote consumption of short-term income forest products. While consumer sentiment studies on short-term income forestry are being conducted as part of efforts to encourage consumption, most of the studies rely solely on a survey-based method. In the information age, consumer sentiment toward consumer goods is reflected mostly on social networking sites due to the spread of the Internet. It is necessary to avoid relying solely on a survey-based method in existing research and directly analyze social networking sites that reflect consumers' wishes. In response, this study identified consumer preferences for major short-term income forest products through social big data analyses and used the results to establish strategies for promoting the sale of short-term income forest products. This paper is different from previous research using only a survey-based method, and it uses SNS to understand consumer preferences. The results of this study are expected to directly help the government or related agencies promote consumption of short-term income forest products and, ultimately, help improve forest-related income and promote healthy forest condition.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.3
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• pp.2155-2163
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• 2020

Background: Various treatments have been proposed for chronic low back pain (CLBP), but recent guidelines and reviews recommend regular physical exercise. However, some other studies have reported opposite results that sling exercise (SE) and other exercises (OE) did not differ in improving CLBP. Objectives: To systematically review and meta-analyze the effects of SE on CLBP in studies published in Korea. Design: A Systemic Review and Meta-analysis. Methods: Randomized controlled trials comparing SE with OE and modality therapy (MT), published up to June 2020, were identified by electronic searches. Primary outcomes were pain and disability. The weighted mean difference (WMD), stand mean difference (SMD) and 95% confidence interval (CI) were calculated using a random-effects model. Results: Based on the results of the meta-analysis, SE was effective for pain in the comparison of SE and MT [short-term: WMD=-1.64, 95% CI (-3.06, -0.22); long-term: WMD=-0.34, 95% CI (-0.42, -0.26)]. It was effective for pain in the comparison of SE and OE [short-term: WMD=-1.18, 95% CI (-2.15, -0.20); long-term: WMD=-0.66, 95% CI (-0.89, -0.43)]. It was also effective for disability in the comparison of SE and MT [short-term: SMD=-15.82, 95% CI (-23.10, -8.54)]. We found no clinically relevant differences in disability between SE and OE. Heterogeneity was high in the comparison of SE and overall variables. Conclusion: If SE is applied to physical therapy to improve the main symptoms of CLBP patients, it may contribute to their recovery. More high-quality randomized studies on the topic are warranted.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.133-144
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• 1998

International capital movement has made progress at global liberalization of finance and foreign exchange, international monetary norm changing into floating exchange rate system, easiness of collection of information and trade at improvement of information communication technology from early of 1970's. Results of empirical test for relation between foreign exchange rate or various determination factors of foreign exchange rate and interest rate are followed by next sentences. First, according to relation between foreign exchange rate and interest rate, correlation for each of variables after OECD entrance is increased. But, long-term & short-term interest rate is affected by Hanbo & Kia's bankruptcy, continuous large scale corporates bankruptcy and crisis of foreign exchange. Therefore, financial instability is occured. If portfolio investment fund has been inflow as it is mollified by continuous shortage of foreign exchange and fall of country's credit rating, it is expected to have positive effect for long-term & short-term interest rate from appreciation of won against dollar. Second, results from relation between determination factor of foreign exchange rate and interest rate are followed by next sentences. If surplus of current account and goods account is continued, yield of corporate bond is to be stable. But, margin of surplus is expected to diminish after second quarter 98, and difference between external and domestic interest (after adjusting foreign exchange rate) is to be diminished. And if net inflows of foreign investor's fund (stock and bond) is diminished, it is to have negative effect for yield of corporate bond. According to foreign investor's investment movement of previous years, hedge fund were stayed at least during two years in Mexico. It means that sudden capital outflow is not to be happened at Korea. But if external factors from depreciation of yen and China's renminbi are instable, interest rate is expected to increase from capital's outflows. Third, if it is to decrease instability of foreign exchange rate from increase in surplus of future current account, credit rating's upwardness, stability of yen and renminbi, foreign exchange rate is expected to be stable. It is expected to have continuous stability from short-term interest rate to long-term interest rate in this empirical test.

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.305-319
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• 2002

International capital movement has made progress at global liberalization of finance and foreign exchange, international monetary norm changing into floating exchange rate system, easiness of collection of information and trade at improvement of information communication technology from early of 1970's. Results of empirical test for relation between foreign exchange rate or various determination factors of foreign exchange rate and interest rate are followed by next sentences. First, according to relation between foreign exchange rate and interest rate, correlation for each of variables after OECD entrance is increased. But, long-term ＆short-term interest rate is affected by Hanbo ＆ Kia's bankruptcy, continuous large scale coporates bankruptcy and crisis of foreign exchange. Therefore, financial instability is occured. If portfolio investment fund has been inflow as it is mollified by continuous shortage of foreign exchange and fall of country's credit rating, it is expected to have positive effect for long-term & short-term interest rate from appreciation of won against dollar. Second, results from relation between determination factor of foreign exchange rate and interest rate are followed by next sentences. If surplus of current account and goods account is continued, yield of corporate bond is to be stable. But, margin of surplus is expected to diminish after second quarter 98, and difference between external and domestic interest (after adjusting foreign exchange rate) is to be diminished. And if net inflows of foreign investor's fund (stock and bond) is diminished, it is to have negative effect for yield of corporate bond. According to foreign investor's investment movement of previous years, hedge md were stayed at least during two years in Mexico. It means that sudden capital outflow is not to be happened at Korea. But if external factors from depreciation of yen and China's renminbi are instable, interest rate is expected to increase from capital's outflows. Third, if it is to decrease instability of foreign exchange rate from increase in surplus of future current account, credit rating's upwardness, stability of yen and renminbi, foreign exchange rate is expected to be stable. It is expected to have continuous stability from short-term interest rate to long-term interest rate in this empirical test.

• ETRI Journal
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• v.29 no.2
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• pp.201-211
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• 2007

This paper focuses on the scheduling problem with the objective of maximizing system throughput, while guaranteeing long-term quality of service (QoS) constraints for non-realtime data users and short-term QoS constraints for realtime multimedia users in multiclass service high-speed uplink packet access (HSUPA) systems. After studying the feasible rate region for multiclass service HSUPA systems, we formulate this scheduling problem and propose a multi-constraints HSUPA opportunistic scheduling (MHOS) algorithm to solve this problem. The MHOS algorithm selects the optimal subset of users for transmission at each time slot to maximize system throughput, while guaranteeing the different constraints. The selection is made according to channel condition, feasible rate region, and user weights, which are adjusted by stochastic approximation algorithms to guarantee the different QoS constraints at different time scales. Simulation results show that the proposed MHOS algorithm guarantees QoS constraints, and achieves high system throughput.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.2
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• pp.112-121
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• 1997

This study is focused on the development and selection of optimal cool tube system to maximize its thermal performance. Cool tube is devised to reduce the heating and cooling load of building by preheating or refreshing of intake air. Finite volume method was adopted to solve the conduction problem between the cool tube and earth. We examine the cool tube system for two operating periods, a short term(12 hours) and a long term(3 months). The results of short term operations reveal that condensation significantly influences and raises the exit air temperature. For long term operations, optimum conditions of cool tube system are obtained with variations of flow-rate, depth, length and diameter of cool tube.

• Journal of Korean Society for Quality Management
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• v.30 no.3
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• pp.1-19
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• 2002

Greenberg(1990) suggested that organizational justice research may potentially explain many organizational behavior outcome variables. One example of nontraditional job behavior is service quality, for it is part of the spontaneous and innovative behaviors noted by Katz(1964). The first purpose of this research is to test the effects of organizational justice on service quality, and the second purpose is to test the moderating effects of sex and tenure on the relationships between organizational justice and service quality According to statistical analysis, only interactional justice had an impact on service quality. Also the results of moderating regression analysis showed that short term employees were more sensitive to distributive justice than long term employees. This result means short term employees are more interested In incentive system than long term employees.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.21-23
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• 2005

NARX(Nonlinear AutoRegressive with eXogenous input) neural network was used for prediction of nuclear reactor behavior which was influenced by control rods in short-term period and also by xenon and boron in long-term period in load following operations. The developed model was designed to predict reactor power, xenon worth and axial offset with different burnup rates when control rod and boron were adjusted in load following operations. Data of UCN 3 were collected by ONED94 code. The test results presented exhibit the capability of the NARX neural network model to capture the long term and short term dynamics of the reactor core and seems to be utilized as a handy tool for the use of a plant simulation.

• Knowledge Management Research
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• v.18 no.1
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• pp.49-65
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• 2017

Financial products entail either gains or losses, and customers' psychological reaction to these gains and losses affect the selection of the financial products. This study explains the financial customers' behavior by introducing consumers' psychological variables such as loss aversion and construal levels. According to the construal level theory, people use more abstract and higher levels of construal to represent objects that are more distant on psychological distance. Based on extant research about loss aversion and construal levels, this study proposes two hypotheses and test the hypotheses. The experimental study examines how loss aversion affects the choice between deposit products and fund products in short-term and long-term investment situations. In the long-term condition the respondents prefer fund products to deposit products, whereas in the short-term condition the respondents have showed the opposite result. Also, the effects of loss aversion on preferences for financial products have interacted with the time horizon of investments. Implications and limitations are discussed to establish more effective marketing strategies based on the results of this study.