• Journal of KIISE:Computer Systems and Theory
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• v.27 no.8
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• pp.730-740
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• 2000

The software rejuvenation method for highly available multiplex systems uses a pro-active fault-tolerant approach to handle system failures. The software rejuvenation prevents failures from occurring, while the previous methods recover from failures after happening. Especially, since the software aging proceeds fast in the software used for the multimedia mobile computing due to the loss of communications or data, the preventive method from failures using software rejuvenation can be used for the multimedia mobile computing. In this paper, according to the operational parameters such as rejuvenation period, rejuvenation time, failure rate and repair rate of the servers, number of running servers, duration of running time, and type of running modes, we calculate steady-state probabilities, downtime, availability, and cost of the multiplex systems using software rejuvenation method. We validate the closed-form solutions of the mathematical model by experiments based on various operational parameters and find that the software rejuvenation method can be adopted as preventive fault-tolerant technique. The failure rate and unstable rate of the servers are essential factors for the decision making of the rejuvenation policies.

• Journal of East-Asian Urban History
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• v.2 no.2
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• pp.235-271
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• 2020

Tainan was the capital of Taiwan and was the largest commercial city in Taiwan with a significant number of ports. However, after the end of the Qing era, the functions of the capital and major ports were shifted to Taipei and Kaohsiung, thus leading Tainan to lose its position. This article focuses on festivals in the city. The Qing dynasty administrative agency set up a local government that grouped multiple villages based on the religious beliefs which were closely related to the concept of the urban space as the primary temple. Mazu is an object of worship that attracted the attention of city residents from the Taisho era to the colonial era. At the Mazu temple in Tainan, which has acquired a new mystery, a Mazu festival was conducted with Mazu patrols. This festival was conducted from 1915 to 1937, when it was canceled due to the temple reorganization movement. At the festival, multiple participating groups used to compete to earn the luxury of running the pavilions. The procession ran through the north side of the city on the first day and the south side of the city on the second day. During this festival, in addition to going around the villages of the old city, a touring route was planned for the procession to pass through major landmarks related to the colonial administration and the Ginza-dori Shopping Street, which was newly created during the Taisho era. Therefore, this procession was unique because it ensured that people could explore the old and new streets that were transformed through urban remodeling during the colonial period. Moreover, passing through the licensed quarters called Shin-machi, which was relocated through urban remodeling by the administrative agency, allowed people to visualize the urban structure of colonial Taiwan. Tainan city was renewed through remodeling during the colonial period, thus leading to the formation of a new commercial area. The spirit of the people in Tainan city can be gauged based on the fact that the festival was financially and religiously supported by the merchants who promoted it. The restoration of Mazu during the colonial period indicates the restoration of urban commerce in Tainan, which had fallen from its position as the primary port city in Taiwan since the end of the Qing period. Therefore, it can be considered to represent the restoration of the city.

• Journal of the Korea Computer Industry Society
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• v.3 no.1
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• pp.77-84
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• 2002

An cluster system used consist of large number of running servers, one has the problem that does the low availability occured by the high chance of the server failures and it is difficult to provide occuring software aging. In this paper, running cluster web servers consists of n primary servers and k backup servers, based on the operational parameters such as number of running primary servers, number of backup severs, rejuvenation period, rejuvenation time, failure rate of sewers, repair rate of servers, unstable rate of servers. We calculate to evaluate the rejuvenation policy such steady-state probabilities, downtime, availability, and downtime cost. We validate the solutions of mathematical model by experiments based on various operation parameters and find that the software rejuvenation method can be adopted as prventive fault tolerant technique for stability of system. The failure rate and unstable rate of the servers are essential factors for decision making of the rejuvenation policies.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.127-137
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• 2011

We have developed a wearable device that can convert sensor data into real-time step counts and activity levels. Sensor data on gait were acquired using a triaxial accelerometer. A test was performed according to a test protocol for different walking speeds, e.g., slow walking, walking, fast walking, slow running, running, and fast running. Each test was carried out for 36 min on a treadmill with the participant wearing a portable gas analyzer (K4B2), an Actical device, and the device developed in this study. The signal vector magnitude (SVM) was used to process the X, Y, and Z values output by the triaxial accelerometer into one representative value. In addition, for accurate step-count detection, we used three algorithms: an heuristic algorithm (HA), the adaptive threshold algorithm (ATA), and the adaptive locking period algorithm (ALPA). A regression equation estimating the energy expenditure (EE) was derived by using data from the accelerometer and information on the participants. The recognition rate of our algorithm was 97.34%, and the performance of the activity conversion algorithm was better than that of the Actical device by 1.61%.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.123-128
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• 2014

This study investigated the exercise intensity and energy expenditure involved in two gardening activities (planting transplants and sowing seeds in a garden plot) and four common physical activities (running, skipping rope, walking, and throwing a ball) in children. Eighteen children aged 11 to 13 years (mean age, $12.3{\pm}0.7$ years) participated in this study. The children made two visits to a high tunnel in Cheongju, Chungbuk, South Korea and performed randomly selected activities. Each activity was performed for 10 min, with a 5-min rest period between activities. The children wore a Cosmed $K4b^2$ (Cosmed $K4b^2$; Cosmed, Rome, Italy), which is a portable calorimetric monitoring system, to measure indicators of metabolic cost such as oxygen uptake and energy expenditure. The children's heart rates during the activities were measured by radiotelemetry (Polar T 31; FitMed, Kempele, Finland). We found that the two gardening and four physical activities performed by the 11-13 years old children in this study were moderate-to high-intensity physical activities [i.e.,$5.4{\pm}0.7$ to $9.1{\pm}1.4$ metabolic equivalents (METs)]. Running ($9.1{\pm}1.4$ METs) and skipping rope ($8.8{\pm}1.1$ METs) were high-intensity physical activities, whereas walking ($6.1{\pm}0.9$ METs), planting transplants ($5.8{\pm}1.1$ METs), throwing a ball ($5.6{\pm}1.1$ METs), and sowing seeds ($5.4{\pm}0.7$ METs) were moderate intensity physical activities. Running and skipping rope were significantly more intense than the other activities (P < 0.0001). The gardening tasks such as planting transplants and sowing seeds in a garden plot showed similar exercise intensities and energy costs as walking and throwing a ball. This study indicates that gardening can be used as a physical activity intervention to provide health benefits similar to more common physical activities such as walking and running.

• The Korean Journal of Physiology
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• v.2 no.2
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• pp.11-20
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• 1968

Maximal oxygen uptake was measured in thirty-three secondary school girls by means of the treadmill test. Eighteen middle school girls aged 14.0 (range: $13.0{\sim}15.9$) years and fifteen high school girls aged 16.9 (range: $16.0{\sim}18.0$) years served as subjects. Maximal treadmill run lasted for 2 minutes and 20 seconds and the expired air was collected in a Douglas bag through a J-valve during the last one minute period. In general, absolute values of various measurements in the high school girls were greater than those of the middle school girls. When values were expressed on the body weight or lean body weight basis, however, work capacity of middle school girls was superior to that of the high school girls. The detailed results are as follows: 1. In middle school girls maximal oxygen uptake was 1.78 l/min., 47.4 ml/kg body weight, 12.3 ml/cm body height, and 61.7ml/kg lean body mass. In high school girls maximal oxygen uptake was 1.93 l/min., 39.7ml/kg body weight, 12.3 ml/cm body height, and 51.2 ml/kg LBM. Although the absolute value of maximal oxygen uptake was greater in high school girls than in middle school girls, values expressed on the body weight basis showed the reverse trend, namely, values of the middle school girls was greater than those of the high school girls. 2. The ratio of maximal to resting oxygen uptake was 8.8 in the middle school girls and was 10.2 in the high school girls. 3. Maximal pulmonary ventilation in the middle school girls was 55.3 l/min. and 66.1 l/min. in the high school girls. The ratio of maximal to resting pulmonary ventilation was 10.2 in the middle school girls and 10.1 in the high school girls. 4. The correlation between body weight and maximal oxygen uptake was relatively high, namely, r=0.79 both in middle and high school girls. The correlation coefficient between body weight and maximal pulmonary ventilation was a little less that of between maximal oxygen uptake and showed a value of r=0.60 both in middle and high school girls. The lean body mass was a poor reference of maximal oxygen uptake or maximal pulmonary ventilation as compared to body weight. The correlation between maximal oxygen uptake and maximal pulmonary ventilation was high and the coefficient of correlation in middle school girls was 0.927 and in high school girls it was 0.856. 5. Maximal ventilation equivalent was 30.9 liters in middle school girls and 33.9 liters in high school girls. This indicated that no hyperventilation was induced during the maximal of oxygen uptake exercise period as related to the maximal oxygen uptake. 6. Heart rate reached to the peak value within 1.5 minutes after beginning of maximal oxygen uptake run and remained at the same peak plateau level throughout the entire running period. Heart rate decreased steeply on cessation of running and subsided slowly thereafter. The maximal heart rate was 184 beat/min. in middle school girls and 189 beat/min. in high school girls. 7. Maximal oxygen pulse was 9.4 in middle school girls and 9.9 ml/beat in high school girls.

• Korean Journal of Construction Engineering and Management
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• v.6 no.2 s.24
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• pp.111-119
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• 2005

Although the life-spans of most apartment buildings are over fifty years, they are often demolished and retrofitted only after twenty years, in spite of its remaining life expectancy, resulting in economical waste. The purpose of this paper is to estimate optimum remodeling period of apartment buildings using total cost. In this study it is seen that total sum of running cost of life-span on the buildings is about 4.69 times of initial cost till the fifty years of the life expectancy. The optimum remodeling period of the apartment building is thirty years applying the discount rate of $4.17\%$ and the discount rate should be $6.122\%$ to obtain the forty years of the optimum remodeling period. From the sensitivity analysis based on the change of the discount rates, it is seen that if discount rate decreases the optimum remodeling period can be extended, or vice versa. As a result, a time of the demolished and remodeling can be expected and the basic data can also be established for lengthening life-span of the apartment buildings.

• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.493-517
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• 2012

This paper analyzes a price discovery process for gasoline among branded and independent stations in Korea using a vector error correction model (VECM) and directed acyclic graphs (DAG). Two data sets for daily prices of medium level gasoline running from April 15, 2008 to May 31, 2009 and from January 1, 2011 to December 31, 2011 are used for empirical analysis. Empirical results show that S-OIL has an exogeneity and played a important role in the flow of price information in the market in the first period. In the second period, SK energy played a key role in price discovery process in the market. The price of NH-OIL stations do not cause the price of any other stations, which implies that the entrance of new branded stations with lower gasoline price to market has no influence on gasoline prices of retail markets.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.883-890
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• 2010

This study is a research results about flow characteristics of debris flow mobilized from landslides such as initiation, transportation and deposition. As results of slope stability analyses at sites studied, the safety factors in rainy period are decreased drastically in comparisons with those in dry period so that the effect of rainfall on initiation of debris flow is known to be significant. From results of analyzing rainfall data, debris flow occurred as previous rainfall accumulated during 2 weeks was more than 526mm, the maximum rainfall intensity being more than 34mm/hr and the day rainfall being more than 171mm/day. As results of analyzing topology of channel debris flow running, the angle of slope where debris flow initiated was in the range of $36{\sim}39^{\circ}$. For area of channel debris flow being transporting the angle of channel was in the range of $11{\sim}36^{\circ}$. The angle of channel where debris flow started to be deposited was found to be in the range of $5{\sim}10^{\circ}$.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.3
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• pp.73-85
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• 2020

The study aims to provide better understanding of sustainable earnings by a comprehensive analysis of earnings persistence of business firms in Vietnam as an example of developing economies in South-East Asia. Dataset of 1,278 publicly listed firms (excluding banking and financial services firms) on Vietnam Stock Exchange for the period from 2008 to 2017 was collected. By applying fixed effect regression model, the empirical results provided the basis to measure the persistence index (Pers index) and find low level of their earnings persistence. The literature of earnings quality analysis in developed countries suggests earnings persistence as a noteworthy determinant of future earnings forecast and stock valuation. However, research of sustainable earnings in developing countries is still highly underdeveloped. For Vietnamese listed firms, the average Pers index was estimated for the period from 2008 to 2010, indicating low level of earnings persistence. We also incorporated earnings persistence level into future earnings forecast by running the quintile regression model divided the data into four equal levels and conducted each section independently to see the difference in each percentile, thence assessed the factors' influence on the specific model. The findings provide important information on the expected returns of firms, especially helping investors make sound decisions.