• The Korean Journal of Applied Statistics
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• v.5 no.2
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• pp.123-137
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• 1992

We analyzed a time series composed of the annual precipitations of Seoul based on the measurements of a Korean raingage and a modern raingage. The precipitations measured with a Korean raingage for the period of 1771 to 1907 are followed by the precipitations with a modern raingage for the period of 1908 to 1990. The latter part of the time series of annual precipitations were obtained from a book for annual precipitations of Korea by Korea Meteorological Administration and the former from Wada's table 1 for monthly precipitations reproduced from the daily rainfall measurements by a Korean raingage for the period of the Yi Dynasty. In our analysis three different precipitation regimes clearly stand out of the entire period. In order to define objectively the period of each precipitation regime we made a time series of 9 year moving averages from the above time series. By taking into account the shapes of the moving average time series and by using a threshold value of annual precipitation 1050 mm, we defined three precipitation regimes of wet period 1(WP1), dry period (DP), and wet period 2 (WP2). The WP1 and WP2 show very similar characteristics in out statistical analyses. On the other hand, DP is very different from the two periods in many statistical aspects. The strong similarities of the WP1 and WP2 regimes in the magnitudes of statistical parameters and in the shapes of their power spectrum distribution are supporting very positively the soundness of precipitation amounts measured with a Korean raingage in spite of numerous conceivable errors which might have been introduced into measurements of precipitation due to changes of observation site and environment, the scale of units employed, and urbanization of Seoul, etc. However, the annual precipitation amounts are not enough to examine throughly the characteristic of precipitation variations during the two regimes. It is definitely necessarly to recover the daily amounts of precipitation, based on two or three times measurements of rainfall with a Korean raingage, scattered in various ancient documents such as the official diary of 'Seungjeong-weon'

• Korean Journal of Applied Biomechanics
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• v.26 no.4
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• pp.397-405
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• 2016

Objective: Pilates is a low/mid-intensity exercise that can be easily performed by elderly individuals as it is an individual body-oriented exercise. It is also a cardio workout that can be performed anywhere to develop strength and flexibility. Therefore, we investigated the effects of 8 week Pilates program on the balancing ability of elderly individuals. Method: The research participants were selected from elderly residents in B city. Ten individuals voluntarily signed an agreement to undergo free measurements as well as to participate in the workout program. (Height: $157.1{\pm}11.9cm$, Weight: $61.7{\pm}8.0kg$). The Pilates exercise was performed 60 minutes a day, three times a week for a total of eight weeks. The measurement variables used to test balance were the vestibular test, 5 m habitual and maximum walk test and 3 m tandem walk test. A series of paired t-test were conducted using IBM SPSS Statistics 23.0 to analyze all the research data collected in order to determine the balance ability of the participants before and after the Pilates program. Additionally, the statistically significant level for all analysis was set to ${\alpha}=.05$. Results: In the vestibular test, some meaningful changes were observed in the length envelope area (ENV) while standing on one foot, but there were no significant differences in the ENV, rectangle(REC), root mean square, and total length. Results also revealed that statistically significant differences existed in the 5 m habitual and maximum walk test, as well as the 3 m tandem walk test. Conclusion: To summarize the findings, the 8 week Pilates program employed in this study significantly improved the dynamic balance of the elderly participants. Thus, elderly individuals that frequent perform Pilates are expected to enjoy positive benefits such as increased balance and fewer falling accidents.

• Journal of Korean Society of Transportation
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• v.30 no.6
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• pp.27-36
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• 2012

In Korea, 28,641 cases of traffic accidents were caused by drunk driving in 2010. These statistics accounted for 12.62% of total number of traffic accidents. Moreover, the percentages of deaths and injuries from them were nearly 15% of those from whole traffic accidents. While police has emphasized enforcement efforts in order to reduce drunk driving, culture generous to drunk driving in addition to the absence of an appropriate intervention system for habitual drunk drivers have contributed to the increasing number of the drunk driving accidents in Korea. This study examined specific behavioral changes in drunk driving by comparing drivers' behavior pattern in non-alcoholic condition to those in alcoholic condition, using a psychomotor test and a driving simulator. In the psychomotor test measuring participants' reactions to the target stimulus, it was revealed that participants' correct responses were decreased, false responses were increased, and no responses also were increased after drinking. Furthermore, in the driving simulator performance after drinking, not only driving speed was faster but also the deviation of an accelerator pedal pressure and of the vehicle's lateral position were much increased. These results indicated that alcohol consumption would impair visio-cognitive ability and deteriorate driving safety. Finally, the implications and limitations of our findings and suggestions for the future research were discussed.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.1
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• pp.88-97
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• 2012

DSOM(Diagnosis System of Oriental Medicine), questionnaire for oriental medical(medicine) diagnosis is an online survey system containing 152 questions for female, 149 questions for male that asking the basic symtoms of 16 pathogenic factors(病機). The result of DSOM denotes reliability according to the level of major symptoms of each pathogenic factor. Standard level of reliability is equal to all 16 pathogenic factor basically except phlegm(痰). In case of phlegm(痰) we give different weight depending on whether the factor includes gray color under the orbit(痰飮氣) or not. To examine reliability of DSOM, statistical analysis has been done to the data of felmale 10101, male 1564 except for bad responses and stored between 1st April 2000 to 3rd June 2011. Based on the study, the conclusions were as follows. Reliability of DSOM. For female, all pathogenic factors showed over 85% confidence level except for phlegm 82.6%. For male, all pathogenic factors showed more than 90% confidence level except two factors, phlegm(痰) indicates 87.% and damp(濕) indicates 89.8%. HH rates among pathogenic factors were more than 50 points. For female, HH rates of other 14 pathogenic factors were all over 80% except for heat(熱) 78.2% and insufficiency of Yang(陽虛) 75.3%. For male HH rates of all pathogenic factors were more than 80% except HH rates of heat 78.2% and damp 77.8%. Research based on a degree of satisfaction of reliability derived from pathogenic factors with scores of HH results in for all 16 pathogenic factors showed over 85% of relatively high level of satisfaction for both sexes whose reliability standard come under 5~4 points. Comparing appearance frequency of pathogenic factors for both sexes. Male only displays higer than female in heat(熱). Whereas female were higher than male for other 15 pathogenic factors and the difference was biggest in heart(心) and least in insufficiency of Yin(陰虛). Comparing appearance frequency order of pathogenic factors for both sexes. Female outdistanced male in blood stasis(血瘀) coldness(寒) blood-deficiency(血虛) phlegm(痰), while male outdistance female in heat(熱) insufficiency of Yin(陰虛) deficiency of qi(氣虛). Male had lower average of each pathogenic factors than female except heat(熱) as well as deficiency of qi(氣虛).

• The Mathematical Education
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• v.59 no.1
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• pp.63-80
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• 2020

This study analyzed 3,114 articles published in KCI journals and 1,636 articles published in SSCI journals from 2000 to 2019 in order to compare domestic and international research trends of mathematics education using a topic modeling method. Results indicated that there were 16 similar research topics in domestic and international mathematics education journals: algebra/algebraic thinking, fraction, function/representation, statistics, geometry, problem-solving, model/modeling, proof, achievement effect/difference, affective factor, preservice teacher, teaching practice, textbook/curriculum, task analysis, assessment, and theory. Also, there were 7 distinct research topics in domestic and international mathematics education journals. Topics such as affective/cognitive domain and research trends, mathematics concept, class activity, number/operation, creativity/STEAM, proportional reasoning, and college/technology were identified from the domestic journals, whereas discourse/interaction, professional development, identity/equity, child thinking, semiotics/embodied cognition, intervention effect, and design/technology were the topics identified from the international journals. The topic related to preservice teacher was the most frequently addressed topic in both domestic and international research. The topic related to in-service teachers' professional development was the second most popular topic in international research, whereas it was not identified in domestic research. Domestic research in mathematics education tended to pay attention to the topics concerned with the mathematical competency, but it focused more on problem-solving and creativity/STEAM than other mathematical competencies. Rather, international research highlighted the topic related to equity and social justice.

• Asia pacific journal of information systems
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• v.23 no.2
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• pp.41-66
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• 2013

IS outsourcing has an important meaning to the Korean SME's (Small and Medium Enterprises) which want to use the IS Services. The objective of this research is to manage IT risks occurred during IS outsourcing project process. This study tries to identify these risks using real option methodology. In order to perform this objective, this study set up the research model which is composed of two main concepts. The first one is the risk factors occurred during IS outsourcing project process: User's Risks, Supplier's Risks and Transaction's Risks. All of these risks are based on Transaction Cost Theory. The second one is the intention to get (or buy) Real Options to manage the risks. In the research model, two types of real option are included: option to abandon (put option) and option to defer (call option). This study uses questionnaires and statistics methodology (PLS) to analyze the hypotheses proposed in the research model. Compared with prior studies, this study is different in two ways. First, this study restricts the range of IT risks. Prior researches of IT Risk management in MIS area cover various range of IT risks, but this study focuses on the Korean SME's IT outsourcing risks on the basis of Transaction Cost Theory. This study tests the relationship between the risks and real option types. Second, this study tries to test the moderating effect of user's risks and supplier's risks on the relationship between transaction's risks and real option types. In IT outsourcing research area, almost studies focus on the direct relationships between IT risks and outsourcing success. But in reality, the co-relationship among IT risks may occur. There are some findings according to the research analysis. First, risks related with user's risks have strong causal relationships with the intention to get option to abandon (put) and option to defer. But risks related with supplier's risks have causal relationships only with option to abandon (put). Second, user's risks and supplier's risks have no moderating effect on the relationship between transaction's risks and real option types. According to the research results, this research have some important and interesting implications on the IS outsourcing business area. First, this study identifies the effective types of real option to minimize the risks occurred during the IT outsourcing projects. So IS outsourcing service users can manage (or minimize) effectively the risks, which occurred during outsourcing projects, using real options. Second, real option gives benefits to suppliers and users at the same time (i.e., win-win strategies between IS outsourcing service providers and users). Vendors (:IS outsourcing service providers) can offer users the real options which can minimize the occurrence of risks in time. "IN TIME" means that before the IS outsourcing project starts, vendors can offer users the opportunity to buy real options in appropriate prices to manage the possibility of the risks of IS outsourcing project. And users also have chance to minimize the IT outsourcing risks occurred during the project process using real options.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.11
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• pp.836-840
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• 2009

Many researchers have studied flash memory in order to replace hard disk storages. Many FTL algorithms have been proposed to overcome physical constraints of flash memory such as erase-before-write, wear leveling, and poor write performance. Therefore, these constraints should be considered for testing FTL algorithms and the performance evaluation of flash memory. As doing the experiments, we suffer from several problems with costs and settings in experimental configuration. When we, for example, replay the traces of Oracle to evaluate the I/O performance with flash memory, it is hard to extract exact traces of I/O operations in Oracle. Since there are only write operations in the log, it is impossible to gather read operations. In MySQL and SQLite, we can gather the read operations by changing I/O functions in the source codes. But it is not easy to search for the exact points about I/O and even if we can find out the points, we might get wrong results depending on how we modify source codes to get I/O traces. The FlaSim proposed in this paper removes the difficulties when we evaluate the performance of FTL algorithms and flash memory. Our Linux drivers emulate the flash memory as a hard disk. And we can easily obtain the usage statistics of flash memory such as the number of write, read, and erase operations. The FlaSim can be gracefully extended to support the additional modules implemented by novel algorithms and ideas. In this paper, we describe the structure of FTL emulator, development tools and operating methods. We expect this emulator to be helpful for many experiments and research with flash memory.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.709-718
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• 2016

The study considers viewpoints for qualitative improvement of landscape planning based on research literature, books and reports. By classifying items used in this study, evaluation criteria was derived for viewpoint selection using SPSS Statistics. In addition, we establish weights and prioritize viewpoints by measuring the relative importance within the hierarchical index. The analysis results are as follows: First, 16 viewpoints were determined using surveys from experts to establish specific and systematic plans for landscape simulation. Second, with respect to the medium classification level of viewpoint evaluation, the most important factor found was 'view' followed by 'publicness' and 'place.' Third, priority by viewpoint was found to exhibit the following order of relative importance: visual openness of viewpoint, favorability as view target, cultural property space, historicity, public place, gateway place, area where the target can be observed, thickly-populated or most-used place, place where various shapes of targets and surrounding landscape can be identified, ecological protection area, river and waterside area, viewing angle (relief-etching), viewing direction, major roads, distance between the viewpoint and the target, and plains and farmland. These results can contribute to developing systematic and reliable analysis frame for qualitative improvement of landscape planning and evaluating landscape simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.582-590
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• 2016

The purpose of this study is to investigate the relationship between suicidal attitude and suicidal ideation of college students and also to provide the fundamental data in order to strengthen both the standard and the recommendation of media coverage in Korea. A total of 249 college students over the age of 18 years in B city and G do were enrolled for this study. The data were collected between June 9 and July 7 of 2014 and analyzed by using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients, and multiple regression with SPSS 21.0. The mean score of a message of suicidal motivation reports 2 was $51.06{\pm}10.55$, which was the highest. The score of suicidal ideation was $10.41{\pm}12.88$. There were sign&ificant differences in suicidal thought with respect to school system, family income, pocket money, time of physical activity, smoking, and smart-phone usage in university students. It was shown that suicidal thoughts were significantly correlated with message of simple suicidal reports 1(r=.303, p<.001), message of suicidal motivation reports 2(r=.251, p<.001), and message of suicidal mourning man reports 3(r=.225, p<.001). As the suicidal attitude have a close association with reports of suicide, it is necessary that studies on a variety of factors influencing suicidal thoughts of students be repeated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.447-457
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• 2016

The purpose of this study is to examine the relationship between stress symptoms and health-promoting behaviors (HPB) among two residence groups of university students. Data were collected by questionnaires from 313 students living in a dormitory and 281 students not living in a dormitory. Data were collected from October 21 to November 20, 2015. Data were analyzed using descriptive statistics, Pearson's correlation coefficient, and stepwise multiple regression. Dormitory residents presented higher HPB scores among both genders. For dormitory residents, smoking and drinking affected the HPB, and for non-dormitory residents, scholastic achievement and health status affected the HPB significantly. HPB had significantly negative correlations with depression, anxiety, and anger for dormitory residents and with cognitive disorganization, depression, and anger for non-dormitory residents. The results of multiple regression analysis show that the significant factors for dormitory students in order of importance were depression, anger, and anxiety, and the variance was 67%. For non-dormitory students, the significant factors were depression and anger with a variance of 63%. The results suggest that it is necessary to develop a suitable HPB program for university students.