• Computational Structural Engineering
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• v.5 no.1
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• pp.91-96
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• 1992

Earthquake resistant design is evolutionary, and, although great progress has been made since seismic design was made mandatory by building codes, it is still not completely understood. In this paper, a 10 story steel building is analyzed and its results are compared by applying two different actual ground motions to the structure. 12 sets of Loma Prieta, California, earthquake data which occurred in 1989, and recorded 7.1 on the Richter scale and 9 sets of Valparaiso, Chile, earthquake data which occurred in 1985, and recorded 7.8 on the Richter scale were scaled to zone 2B level of UBC-88. By applying earthquake ground motions which had similar Richter scale magnitude, it was found that the Chile earthquake which had long duration of ground motion affected about twice bigger than that of California earthquake which had relatively short duration of ground motion. In addition to the peak ground motion, the duration of the ground motion is a very important factor in structural design.

• Journal of muscle and joint health
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• v.5 no.2
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• pp.222-237
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• 1998

In an attempt to investigate the effect of long-term aquatic exercise program on lower limbs' muscle strength, knee Joint flexion, pain reduction and weight changes with aquatic exercise program. Forty three women with arthritis were pre and post tested for changes of muscle strength, range of motion, weight and pain. This data was collected from April 1, 1997 to February 24, 1998. The mean age was 52.5. Statistically significant in lower limbs' muscle strength with an aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in knee joint flexion with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in pain reduction with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in weight changes with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 6 weeks after experiment. As a conclusion, aquatic exercise programs for the patients with arthritis require at least 12 weeks and a variety of aquatic exercise programs for the effective control should be developed.

• Journal of Environmental Science International
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• v.20 no.11
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• pp.1457-1464
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• 2011

In this study, the method of estimating hydrologic information (water depth, submerged period etc.) on the proper selection of construction point and scale as well as vegetation type suggested for the design of natural riparian rehabilitation structure. Long-term comprehensive watershed model SWAT-K(Korea) was applied to this purpose. Flow duration analysis was conducted to analyze the hydrologic characteristics of Pyungchang watershed at which the 'bangtul' construction method was tested. For this purpose 20 years (1989-2008) rainfall runoff analysis was carried out. Based on the simulated daily streamflow data, flow duration curve was made to analyze the flow characteristics, and the water depth hydrograph was made to analyze the water depth distribution at the cross section. Finally, the information for the selection of proper vegetation according to the submerged period is suggested.

• Women's Health Nursing
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• v.11 no.2
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• pp.142-147
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• 2005

Purpose: The objectives of this study were to investigate the current breast feeding rates in Jeju Province and to identify factors which influence breast feeding duration after birth. Method: The subjects were 189 women with a child between 12 months and 24 months old. Data was collected using a structured questionnaire from October 2003 to January 2004. Measures used in this study included general characteristics, delivery related characteristics, breast feeding related characteristics and the feeding type over a 12-month period after birth. Result: The study showed that the breast feeding rate in the first month was 63.1%, later dropping to 30.9% in the sixth month. In addition, only 14.2% of subjects were still breast feeding the baby at twelve months of age. The mean of breast feeding duration was 4.77 months. The factors which influenced breast feeding duration were wanted pregnancy, breast feeding education, planning of breast feeding and breast feeding experience. Conclusion: Considering the low rate of long-term breast feeding, the importance of breast feeding should be emphasized to promote and support the continuation of breast feeding in addition to at its initial stage. Based on the results, programs on breast feeding promotion and continuation need to be developed.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.148-157
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• 2022

Every year, particularly during the monsoon rainy season, landslides at the Chuncheon province of South Korea cause tremendous damage to lives, properties, and infrastructures. More so, the high rainfall intensity and long rainfall days that occurred in 2020 have increased the water content in the soil, thereby increasing the chances of landslide occurrences. Besides this, the rainfall thresholds and characteristics responsible for the initiation of landslides in this region have not been properly identified. Therefore, this paper addresses the rainfall thresholds responsible for the initiation of landslides at Chuncheon from a regional perspective. Using data obtained from rainfall measurements taken from 2002 to 2011, we identify a threshold relationship between rainfall intensity and rainfall duration for the initiation of landslides. In addition, we identify the relationship between the rainfall intensity using a 3-day, 7-day, and 10-day antecedent rainfall observation. Specifically, we estimate the rainfall data at 8 sites where debris flow occurred in 2011 by kriging. Following this, the estimated data are used to construct the relationship between the intensity (I), duration (D), and frequency (F) of rainfall. The results of the intensity-duration-frequency (IDF) analysis show that landslides will occur under a rainfall frequency below a 2-year return period at two areas in Chuncheon. These results will be effectively used to design structures that can prevent the occurrence of landslides in the future.

• Asia-Pacific Journal of Business
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• v.12 no.1
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• pp.25-39
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• 2021

Purpose - This study aims to examine whether family firm governance is related to long-term corporate survival. To find out whether and why family firms have higher chances of long-term survival compared to non family firms, this study analyzes the relationship between some governance characteristics that are prevalent in family firms and corporate long-term viability. Design/methodology/approach - This study utilizes a sample of 285 family firms listed on the Korea Stock Exchange (KSE) to probe the influence of governance characteristics on corporate survival. This study conducts Cox proportional hazard regression analysis to estimate the influences on the survival duration. Findings - The results indicate that firms with particular governance characteristics show higher long-term survivability. Specifically, the probability of firm's long-term survival is increased when the CEO is the largest shareholder, which may be related to CEO's stewardship attitudes. Research implications or Originality - This study has significance in that it examines the direct causal variables that enhance long-term corporate viability through a large scale empirical examination. Also, the study findings provide some clues as to why certain family firms outlive non-family firms.

• Structural Engineering and Mechanics
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• v.75 no.3
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• pp.377-387
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• 2020

Modern long-span floor system typically possesses low damping and low natural frequency, presenting a potential vibration sensitivity problem induced by human activities. Field test and numerical analysis methods are available to study this kind of problems, but would be inconvenient for design engineers. This paper proposes a simplified method to determine the acceleration amplitudes of long-span floor system subjected to walking or running load, which can be carried out manually. To theoretically analyze the acceleration response, the floor system is simplified as an anisotropic rectangular plate and the mode decomposition method is used. To facilitate the calculation of acceleration amplitude a_P, a coefficient α_wmn or α_Rmn is introduced, with the former depending on the geometry and support condition of floor system and the latter on the contact duration t_R and natural frequency. The proposed simplified method is easy for practical use and gives safe structural designs.

• The Korean Journal of Pain
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• v.3 no.1
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• pp.59-62
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• 1990

Epidural block is used for surgical analgesia, postoperative pain management, obstetric relief and management of chronic pain. Long-term pain control for chronic pain is achieved by development of epidural catheter placement technic. But long term placement of epidural catheteter has several problems, epidural hematoma, epidural absess and neural damage. We had successfully managed long-term placement of epidural catheter in patient with diabetic neuropathy who was susceptable to infection. The duration of epidural catheter placement was 416 days and specific complication was not occurred.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.12
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• pp.570-575
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• 2006

This paper develops methodology in order to consider CHP(Combined Heat and Power) capacity in the Basic Plan of Long Term Electricity Supply & Demand. We develop generating cost of CHP considering electric and heat. Also we develop mixed load duration curve which includes the electric load and heat load and then apply CHP capacity to SCM(Screening Curve Method) considering CHP feature. Accordingly, it decide the optimal CHP capacity in the Basic Plan of Long Term Electricity Supply & Demand. Also, We perform the sensitivity analysis according to cost variation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.4
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• pp.191-199
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• 2000

Since a few decade ago, there has been a demand on the safety monitoring of civil infrastructures, such as bridges, in order to prevent possibly occurrable disaster due to human negligence. The main cause for a failure or collapse of structures is absolutely a structural crack. For the reason, it is necessary to monitor the propagation of a structural crack. But a crack in bridges is gradually propagating with the traffic loads through the long term. There are lots of sensors to monitor structural cracks on bridges, but much information about them was not given so far. Therefore, in this study, the experimental comparison for long-term monitoring sensors, especially, strain measurement sensors, in terms of duration, temperature dependency, accuracy was made extensively.