• Title/Summary/Keyword: longitudinal studies

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Topographic characteristics of Yeonho lake, Uljin-gun, Gyeongsangbuk-do (경북 울진 연호(蓮湖)의 지형적 특성)

  • Woo, Seung-Hyun
    • Journal of the Korean association of regional geographers
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    • v.22 no.1
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    • pp.211-224
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    • 2016
  • Natural lakes are estimated in variety with that's function or value depending on age environment or geographical characteristics. There are many kind of natural lakes, but the kind of natural lake is limited in rivers in korea flowing into East Sea. However, Yeonho lake in Uljin has different geographical characteristics with oxbow lake or lagoon which is common in korea's river flowing into East Sea. Therefore the purpose of this study is to analyze geographical characteristics due to the process of Yeonho's formation. Further more research for protecting wetland is needed to adequately preserve, depending on the geomorpologic process. To analyze geographical characteristics, it was essential to compare and analyze topographical map of 1918 1956 2012 and I pictured estinated line of bedrock and longitudinal section of Nam-dae cheon(Riv) Yeonho cheon(Riv). In addition, I denoted flooded areas through design flood level of Nam-dae cheon(Riv) Yeonho cheon(Riv) and analyzed particle size distribution of deposited sediment due to consider deposit environment. The results of study are as follows. In conclusion, Yeonho lake is floodbasin which was not researched at river flowing into East Sea. Through this study, my opinion is that floodbasin can be formed in the river that is steep and short. I argue that preservation methods will be seeked by geomorphologic process of floodbasin and development of downtown.

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Reliability Evaluation for Prediction of Concrete Compressive Strength through Impact Resonance Method and Ultra Pulse Velocity Method (충격공진법과 초음파속도법을 통한 콘크리트 압축강도 예측의 신뢰성 평가)

  • Lee, Han-Kyul;Lee, Byung-Jae;Oh, Kwang-Chin;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.4
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    • pp.18-24
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    • 2015
  • Non-destructive testing (NDT) methods are widely used in the construction industry to diagnose the defects/strength of the concrete structure. However, it has been reported that the results obtained from NDT are having low reliability. In order to resolve this issue, four kinds of NDT test (ultrasonic velocity measurements by P-wave and S-wave and the impact resonance methods by longitudinal vibration and deformation vibration) were carried out on 180 concrete cylinders made with two kinds of mix proportions. The reliability of the NDT results was analyzed and compared through the measurement of the actual compressive strength of the concrete cylinders. The statistical analysis of the results was revealed that the ultrasonic velocity method by S-wave is having lowest coefficient of variation and also most capable of stable observation. Analytical equations were established to estimate the compressive strength of the concrete from the obtained NDT results by relating the actual compressive strength. Moreover the equation established by the ultrasonic velocity method by S-wave had the highest coefficient of determination. Further studies on the stability of non-destructive testing depending on various mixing conditions will be necessary in the future.

A Study on the Evaluation of Logistics Efficiency in 22 cities of Guangxi and Yunnan (광서성 및 운남성 22개 도시의 물류 효율성 평가에 관한 연구)

  • Zhou, Yi Xi;Jeon, Jun-Woo;Kim, Hyung-Ho
    • Journal of Digital Convergence
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    • v.18 no.9
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    • pp.81-91
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    • 2020
  • The logistics industry is a basic and strategic industry that supports the development of national economy and society. The purpose of this paper is to evaluate the logistics efficiency of 22 cities in Guangxi and Yunnan provinces in China, and to grasp the problems and constraints and present policy proposals to promote the transformation and upgrading of the industrial structure in Guangxi and Yunnan provinces. In this paper, five input indexes and four output indexes were selected and the data from 2016 to 2018 were analyzed through DEA method. According to the analysis, the logistics efficiency of Guangxi and Yunnan provinces is not bad overall, but the development of each region is not balanced and the level of logistics efficiency is quite different. And it is found that each city needs to further improve the level of scale because the input and production structure of logistics resources is unreasonable. The limitation of this study is that it is difficult to generalize the analysis results because only the data over the past three years have been analyzed. It is necessary to comprehensively implement longitudinal and transverse analyses by extending the future analysis period over a long period of time.

Development of a Maternal Identity Scale for Pregnant Women (임부의 모성 정체성 측정을 위한 척도개발)

  • 김혜원;홍경자
    • Journal of Korean Academy of Nursing
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    • v.26 no.3
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    • pp.531-543
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    • 1996
  • This study was done to develop a Maternal Identity Scale for Pregnant Women and to test the validity and reliability of the scale. A convenience sample of 161 pregnant women were asked to complete the MISP questionnaire which consisted of 45 item, this was done from December 20, 1995 to January 15, 1996. The research procedure were as follows. The first step was to identify a conceptual definition of maternal identity using Robin(1984)'s maternal identity and maternal experience during pregnancy. The second step was to operationalize the maternal identity, that is, perception of image possible of selves as mother, maternal role play by imagination, and the experiences of various emotional responses which are embedded in the mother-fetus dyad. The third step was item development which resulted in 45 items as appropriate measurement of maternal identity are except for the perception of image possible of selves as mother. The result findings were as follows : 1) Four factors for MISP (finally 40 items) were extracted through the principal component analysis and varimax rotation, and these contributed 49.3% of the variance in the total score. All 40 items in the scale loaded above .43 on one of 4 factors. 2) Each factor was named : factor 1 was named maternal role imagery and has 10 items, factor 2 was named happiness and has 11 items, factor 3 was named maternal fetal interaction and has 10 items, and the last factor 4 was named negative emotion and has 9 items. 3) Cronbach's -alpha coefficient for internal consistsncy was .92 for the total 40 items and .89, .90, .86, .78 for the four subscales in that order. Recommendations are suggested below : 1) The developed MISP be used to assess maternal readiness in pregnancy. 2) Replication study be done to test validity and relaibility. 3) For the overall measure of Maternal Identity in Pregnancy, scale for the perception of image possible of selves as mother, and cognitive domain be reorganized for the maternal identity in pregnancy. 4) It is necessary to identify variables that influences maternal pregnancy. 5) It Is necessary to identify that maternal identity in pregnancy is a reliable index of motherhood, to do correlation studies on maternal identity and major maternal variables in maternal transition period, to reoperationalize the maternal identity in postpartum, and finally to designate a longitudinal study of the maternal identity changes or stabilities.

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Evaluation on Stress-Strain-Strength Behavior of the Textile Encased Soils via Triaxial Compression Tests (삼축압축시험을 통한 섬유로 구속된 흙의 응력-변형률-강도 거동 평가)

  • Yoo, Wan-Kyu;Kim, Byoung-Il;Cho, Wanjei
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.643-653
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    • 2013
  • Recently, there are an increasing number of studies on the method of wrapping the outer wall of granular piles with geosynthetic fibers such as geotextile or geogrid that has a certain level of tensile strength as an alternative method for the ground improvement techniques. In this study, triaxial compression tests are performed on the sand and clay specimen encased with various textiles to evaluate the reinforcing effect with regard to the tensile strength of the textile. Furthermore, triaxial compression tests are performed on the clay specimen inserted by sand only and sand encased with geosynthetics to compare behavioral differences between the conventional sand compaction pile and geosynthetic encased sand pile with regard to the replacement ratio, ${\alpha}_s$ and the tensile strength of the geosynthetics. Based on the experimental results, the strength enhancement due to the textile is affected by the longitudinal tensile strength rather than the transverse one of the applied textile. The effect of the confinement by the textile encasement results in the large increase of the cohesions. The overall behaviors, such as shear strength, pore pressure parameter at failure and stress ratio, of the geosynthetic encased sand pile is quite different from those of the conventional sand compaction pile.

Associations Between Body Fat Percentage and Fitness among Police Officers: A Statewide Study

  • Violanti, John M.;Ma, Claudia C.;Fekedulegn, Desta;Andrew, Michael E.;Gu, Ja K.;Hartley, Tara A.;Charles, Luenda E.;Burchfiel, Cecil M.
    • Safety and Health at Work
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    • v.8 no.1
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    • pp.36-41
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    • 2017
  • Background: Police work is generally sedentary although there may be situations that require physical endurance and strength, such as foot chases and arresting suspects. Factors such as excessive body fat can impede an officer's physical ability to deal with such occurrences. Our objective was to examine associations between officers' body fat percentage (BF%) and performance on a standardized fitness protocol. Methods: Data were obtained from fitness screening among 1,826 male and 115 female officers in a large US police agency. The screening consisted of a 2.4-km run, push-ups, sit-ups, and sit-and-reach test. Sex-specific body fat percentages were estimated from skinfold thickness measured using calipers. Linear regression models were used to examine unadjusted and adjusted mean scores of fitness tests across BF% tertiles. Results: The prevalence of overall fitness was 4.3 times greater in male officers and 3.6 times greater in female officers having the lowest BF% tertile compared with the highest tertile (30.3% vs 7.1% and 46.0% vs 12.8%, respectively). BF% was linearly and positively associated with the time of 2.4-km run (p < 0.001), and linearly and inversely associated with the number of push-ups (p < 0.001), sit-ups (p < 0.001), and the distance of sit-and-reach (p < 0.001) in men. Similar associations were observed in women with the exception of sit-and-reach (p = 0.122). Associations were independent of age, race/ethnicity, rank, and duty station. Conclusion: Overall, BF% was inversely associated with fitness levels in male and female officers. Future longitudinal studies should be initiated to explore the potentially causal relationship between BF% and fitness in law enforcement officers.

Customer Relationship Management Techniques Based on Dynamic Customer Analysis Utilizing Data Mining (데이터마이닝을 활용한 동적인 고객분석에 따른 고객관계관리 기법)

  • 하성호;이재신
    • Journal of Intelligence and Information Systems
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    • v.9 no.3
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    • pp.23-47
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    • 2003
  • Traditional studies for customer relationship management (CRM) generally focus on static CRM in a specific time frame. The static CRM and customer behavior knowledge derived could help marketers to redirect marketing resources fur profit gain at that given point in time. However, as time goes, the static knowledge becomes obsolete. Therefore, application of CRM to an online retailer should be done dynamically in time. Customer-based analysis should observe the past purchase behavior of customers to understand their current and likely future purchase patterns in consumer markets, and to divide a market into distinct subsets of customers, any of which may conceivably be selected as a market target to be reached with a distinct marketing mix. Though the concept of buying-behavior-based CRM was advanced several decades ago, virtually little application of the dynamic CRM has been reported to date. In this paper, we propose a dynamic CRM model utilizing data mining and a Monitoring Agent System (MAS) to extract longitudinal knowledge from the customer data and to analyze customer behavior patterns over time for the Internet retailer. The proposed model includes an extensive analysis about a customer career path that observes behaviors of segment shifts of each customer: prediction of customer careers, identification of dominant career paths that most customers show and their managerial implications, and about the evolution of customer segments over time. furthermore, we show that dynamic CRM could be useful for solving several managerial problems which any retailers may face.

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Formation processes of low river terraces in Korea (우리나라 저위하안단구(低位河岸段丘)의 형성요인)

  • Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.7 no.2
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    • pp.71-81
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    • 2001
  • According to the change of stream power/resisting power relationship due to the crustal movement or the climatic change, most channel landforms which reflect the equilibrium state of fluvial system are eroded and a part of them is remained as a river terrace. In many rivers in Korea are extensively distributed the relatively younger low river terraces. But their accurate formation mechanism is not known. In this paper, the formation processes and the dating of low river terraces distributed in Nakdong River basin will be investigated. Stream power of the downward erosion was revived because the sea level fell down. So stream power was superior to the resisting power under the cool-wet climatic condition during the last glacial period. Thus the river bed was excavated deeply, so that low river terraces were built up. And many incised meander loops were cut during this period. But, when fluvial system did not have equilibrium over all reaches, the last glacial period ended and the sea level initiated to rise rapidly. The headward erosion from the fall of sea level during the last glacial period had kept up to Hagye Fall because of the cutting of incised meander loops. Deeply excavated valleys and abandoned channel of cut-meander in lower reaches of a stream were filled with sediments. Thus the longitudinal profile of the uppermost reaches reflect the last interglacial, the upper reaches the last glacial, and the middle/1ower reaches recent fluvial system. Therefore low river terraces have been formed since the last glacial period.

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Effects of Professional Development for Equity: Focusing on High School Students' Attitudes toward Mathematics (교육 형평성을 위한 고등학교 수학 교사 교육 시행 효과: 학생들의 수학 정의적 영역을 중심으로)

  • Kim, Yeon
    • School Mathematics
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    • v.19 no.4
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    • pp.751-774
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    • 2017
  • Having mathematics for everyone in terms of students' mathematics achievement and attitudes toward mathematics is challenging in high school in South Korea. To gain such purpose, teachers are supposed to have a considerable amount of knowledge and develop mathematical and pedagogical reasoning and insight because equity can be fulfilled in mathematics classroom when any student share their ideas and have mathematical discussions. As a part of a large project aimed to develop and enact professional development for equity and examine its effects and, finally, to propose the direction of professional development to help students cognitively and affectively balanced grow in mathematics, the current study briefly introduces how such professional development was designed and implemented. This study reports its effect based on the statistical analysis of students' responses for the three different surveys, which are parts of the National Assessment of Educational Achievement study, TIMSS Advanced, and the survey about classroom interaction. The data collected in all students in school whose three mathematics teachers had participated in the professional development for two years. The findings consistently indicate the strong and impressive growths in students' attitudes toward mathematics, which are statistically significant. Furthermore, their attitudes toward mathematics are also related to interactions in a mathematics classroom. Based on such results, this study claims expansion of professional development for equity.

Analysis and Application of Nursing Management Practicum Case Simulation for Developing Performance-Centered Education (성과중심 교육과정 개발을 위한 간호관리실습 사례시뮬레이션 적용 및 내용 분석)

  • Lim, Ji Young;Ko, Gug Jin
    • The Journal of the Korea Contents Association
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    • v.17 no.9
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    • pp.235-254
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    • 2017
  • The purpose of this study was to develop a nursing management case simulation (NMCS) framework based on the five components of nursing management process and to apply it to clinical nursing practice of nursing college students. The subjects of this study were NMCS reports submitted by the 4th grade 105 nursing students of an university. The research tool is a simulation framework for nursing management practice. It reflects the brainstorming and debriefing process used in the previous simulation exercise based on the five elements of planning, organization, human resource management, directing and control of the nursing management process respectively. As a result of the study, 32 nursing management cases were found to have 79.6% correct rate, 11.6% concept error rate, and 5.6% classification error rate in the first brainstorming and debriefing process for the five components of nursing management process. On the other hand, in the second brainstorming and debriefing process, 94.6% correct rate, 0.0% concept error rate, and 4.4% classification error rate. Based on these results, the NMCS framework developed in this study can be applied to the nursing management theory and practice course of nursing college students as well as simulation based job training and maintenance educations for clinical nurses. Therefore, we propose follow-up studies in various clinical nursing settings and a longitudinal cohort study to investigate the effect of nursing management job skills of nursing college students after graduation.