• Title/Summary/Keyword: Data-driven

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A Study on the Characteristics of Urban Public Transportation Information Services Use (도시 대중교통정보 이용 행동 특성 연구)

  • Joh, Chang-Hyeon;Lee, Back-Jin;Bin, Mi-Young
    • Journal of the Economic Geographical Society of Korea
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    • v.12 no.1
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    • pp.56-66
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    • 2009
  • As the amount of information is rapidly growing, and the ubiquitous urban environments are emerging, the question which information type to provide and which communication media to support is a major challenge for commercial and public travel-information service providers. The current research reports the first findings of analyses of recent data, collected in metropolitan Seoul, about the acquisition of travel information and the communication media used. The study is based on the assumption that information acquisition and choice of communication medium is strongly context-driven. The study applies CHAID analysis to find homogeneous segments in information acquisition and use of communication media. Findings indicate that transport mode and activity are important determinant of information acquisition and choice of media. The type of travel information acquired co-varies strongly with transport mode and activity. In addition, we found evidence of time of day effects. Similarly, the choice of communication medium depends on the type of travel information searched for, transport mode and activity. The results suggest important implications of managerial and policy measures, in particular the dynamic, contextual market segmentation.

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Palaeodepositional Environment of the Cretaceous Hampyeong Basin, Southwestern Korea (한반도 남서부 중생대 백악기 함평퇴적분지의 고퇴적환경연구)

  • You, Hoan-Su;Kenrick, Paul;Koh, Yeong-Koo;Yun, Seok-Tai;Kim, Joo-Yong;Kim, Hai-Gyoung;Chung, Chul-Hwan;Ryu, Sang-Ock
    • Journal of the Korean earth science society
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    • v.21 no.6
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    • pp.683-694
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    • 2000
  • Abstrace: The palaeodepositional environment and age of the Cretaceous Hampyeong Basin (southwestern Korea) are reassessed based on new geochemical, lithological, sedimentological, and palaeobotanical data. Results indicate that the Hampyeong Basin was a tectonically active basin comprising predominantly fluvial and lacustrine sediments. Four distinctive facies types have been identified (acidic tuff, black shales/sandstones, red beds, intermediate tuff with tuffaceous conglomerate) and these reflect periods of significant environmental change within the basin and its neighbouring terrains. Volcanism driven by tectonic events provides a source for much of the sediment. The sedimentary sequences compare well with those in the neighbouring Haenam Basin. Sediments of volcanic origin are similar to those of the Neungju Formation of the Yuchon Group. The widespread occurrence of black shales is indicative of extended periods of deposition under anoxic conditions. Measurements of total organic carbon show that the values for the black shales (0.81% to 1.75%) are the average for petroleum source shales. Fossil plants occurred in the black shales and sandstones. The occurrence of platanoid leaves places these sediments in Oishi's angiosperm series, which is consistent with an Aptian/Albian or younger age.

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A Study on Value Orientation of Health of Rural Health Center Milieu (농촌지역 보건소 환경에 있어서의 건강가치관에 관한 일 조사연구)

  • 김순자
    • Journal of Korean Academy of Nursing
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    • v.5 no.1
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    • pp.17-30
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    • 1975
  • The concept and definition of nursing and her role have been changing in accordance with the socio-cultural factors of the initial society. At present, nursing is conceptualized as a health care profession assisting man to restore, maintain and promote health by providing knowledge, wilt strength and resources through various processes of interaction. Man′s behavior, of individual and group activities for health inclusive, is driven by the initial man′s value orientation. The purpose of this study is to investigate the value orientation regarding health of rural health center milieu in order to give data for; 1. the planning for the delivery of community nursing service, 2. the health education plan at all level of nursing care activities, and 3. the planning of curriculum for nursing education. A hundred opinion leaders among the labor population residing in rural areas (P-group), hundred and six professional nurses at rural health centers (N-group) were indirectly interviewed through questionaries. And ninety five of N-group were interviewed likewise of their perceptions of P-group (NP-group) from July 15, to October 15, 1974. The result is as follows: 1. Maintenance of health is revealed to be the most valued component for man′s happiness in all the three groups. (P-group: 7.30 S. D.=1.31), (N-group :7.84 S. D. =49), and (NP-group : 5.93 S. D. =2.28) 2. The average value score of the maintenance of health revealed significant difference by P〈.001 level between each of the three groups. (Between N-group and P-group : T= -4.07 P and NP ; T=-6.93, N and NP: T=-9.35) 3. Basic health maintenance activities necessary for maintenance and promotion of personal health were moderately valued by all the three groups, P-group ; 3.74 (S. D. =.43) , N-group: 3.52 (S. D. =.34), NP-group: 3.07 (S. D. :.55) Among the 8 categories of basic health maintenance activities, "food intake" was highly valued by P-group (mean value score; 4.00 S. D=.51) , "exercise and rest" and "personal cleanliness" was highly valued by both P-group (4.02, 4.08) and N-group (4.08, 4.22). 4. The mean value score of basic health maintenance activities revealed significant difference by P〈.001 level between each of the three groups (between P-group and N-group: T=-4, 07, N-and NP: T=-6.93, P and NP T=-9.35) 5. Among the 30 questionaries, dynamic activities for health maintenance were more valued in comparison to passive activities in an tile three groups. 6. In N-group, correlation between the value of basic health maintenance activities and the personal health status personal revealed moderate significance. Correlation between the value of basic health maintenance activities and the age revealed low significance. 7. In group, correlation between the value of basic health maintenance activities and; perception of personal health status revealed non significance, between the age and sex revealed low sign affiance, and between the educational status revealed moderate significance. Recommendations are as follows ; 1. The efforts towards alteration of value orientation concerning health in general in community nursing practice de focussed be that of family Planning. 2. In order to prepare professional nurses competent in understanding individual and group, social science and behavioral science be strength ended in planning nursing curriculum. 3. Milieu of nursing experience during nursing education be Planned to begin at simple nursing problem and move towards complex, f. e. home care towards health crisis situation in order to achieve dynamic role mastery.

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Submarket Identification in Property Markets: Focusing on a Hedonic Price Model Improvement (부동산 하부시장 구획: 헤도닉 모형의 개선을 중심으로)

  • Lee, Chang Ro;Eum, Young Seob;Park, Key Ho
    • Journal of the Korean Geographical Society
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    • v.49 no.3
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    • pp.405-422
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    • 2014
  • Two important issues in hedonic model are to specify accurate model and delineate submarkets. While the former has experienced much improvement over recent decades, the latter has received relatively little attention. However, the accuracy of estimates from hedonic model will be necessarily reduced when the analysis does not adequately address market segmentation which can capture the spatial scale of price formation process in real estate. Placing emphasis on improvement of performance in hedonic model, this paper tried to segment real estate markets in Gangnam-gu and Jungrang-gu, which correspond to most heterogeneous and homogeneous ones respectively in 25 autonomous districts of Seoul. First, we calculated variable coefficients from mixed geographically weighted regression model (mixed GWR model) as input for clustering, since the coefficient from hedonic model can be interpreted as shadow price of attributes constituting real estate. After that, we developed a spatially constrained data-driven methodology to preserve spatial contiguity by utilizing the SKATER algorithm based on a minimum spanning tree. Finally, the performance of this method was verified by applying a multi-level model. We concluded that submarket does not exist in Jungrang-gu and five submarkets centered on arterial roads would be reasonable in Gangnam-gu. Urban infrastructure such as arterial roads has not been considered an important factor for delineating submarkets until now, but it was found empirically that they play a key role in market segmentation.

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Design and Implementation of Web GIS Server Using Node.js (Node.js를 활용한 웹GIS 서버의 설계와 구현)

  • Jun, Sang Hwan;Doh, Kyoung Tae
    • Spatial Information Research
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    • v.21 no.3
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    • pp.45-53
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    • 2013
  • Web GIS, based on the latest web-technology, has evolved to provide efficient and accurate spatial information to users. Furthermore, Web GIS Server has improved the performance constantly to respond user web requests and to offer spatial information service. This research aims to create a designed and implemented Web GIS Server that is named as Nodemap which uses the emergent technology, Node.js, which has been issued for an event-oriented, non-blocking I/O model framework for coding JavaScript on the server development. Basically, NodeMap is Web GIS Server that supports OGC implementation specification. It is designed to process GIS data by using DBMS, which supports spatial index and standard spatial query function. And NodeMap uses Node-Canvas module supported HTML5 canvas to render spatial information on tile map. Lastly, NodeMap uses Express module based connect module framework. NodaMap performance demonstration confirmed a possibility of applying Node.js as a (next/future) Web GIS Server development technology through the benchmarking. Having completed its quality test of NodeMap, this study has shown the compatibility and potential for Node.js as a Web GIS server development technology, and has shown the bright future of internet GIS service.

Design of X-band 40 W Pulse-Driven GaN HEMT Power Amplifier Using Load-Pull Measurement with Pre-matched Fixture (사전-정합 로드-풀 측정을 통한 X-대역 40 W급 펄스 구동 GaN HEMT 전력증폭기 설계)

  • Jeong, Hae-Chang;Oh, Hyun-Seok;Yeom, Kyung-Whan;Jin, Hyeong-Seok;Park, Jong-Sul;Jang, Ho-Ki;Kim, Bo-Kyun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.11
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    • pp.1034-1046
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    • 2011
  • In this paper, a design and fabrication of 40 W power amplifier for the X-band using load-pull measurement of GaN HEMT chip are presented. The adopted active device for power amplifier is GaN HEMT chip of TriQuint company, which is recently released. Pre-matched fixtures are designed in test jig, because the impedance range of load-pull tuner is limited at measuring frequency. Essentially required 2-port S-parameters of the fixtures for extraction optimal input and output impedances is obtained by the presented newly method. The method is verified in comparison of the extracted optimal impedances with data sheet. The impedance matching circuit for power amplifier is designed based on EM co-simulation using the optimal impedances. The fabricated power amplifier with 15${\times}$17.8 $mm^2$ shows the efficiency above 35 %, the power gain of 8.7~8.3 dB and the output power of 46.7~46.3 dBm at 9~9.5 GHz with pulsed-driving width of 10 usec and duty of 10 %.

Evaluation of carbon flux in vegetative bay based on ecosystem production and CO2 exchange driven by coastal autotrophs

  • Kim, Ju-Hyoung;Kang, Eun Ju;Kim, Keunyong;Jeong, Hae Jin;Lee, Kitack;Edwards, Matthew S.;Park, Myung Gil;Lee, Byeong-Gweon;Kim, Kwang Young
    • ALGAE
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    • v.30 no.2
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    • pp.121-137
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    • 2015
  • Studies on carbon flux in the oceans have been highlighted in recent years due to increasing awareness about climate change, but the coastal ecosystem remains one of the unexplored fields in this regard. In this study, the dynamics of carbon flux in a vegetative coastal ecosystem were examined by an evaluation of net and gross ecosystem production (NEP and GEP) and $CO_2$ exchange rates (net ecosystem exchange, NEE). To estimate NEP and GEP, community production and respiration were measured along different habitat types (eelgrass and macroalgal beds, shallow and deep sedimentary, and deep rocky shore) at Gwangyang Bay, Korea from 20 June to 20 July 2007. Vegetative areas showed significantly higher ecosystem production than the other habitat types. Specifically, eelgrass beds had the highest daily GEP ($6.97{\pm}0.02g\;C\;m^{-2}\;d^{-1}$), with a large amount of biomass and high productivity of eelgrass, whereas the outer macroalgal vegetation had the lowest GEP ($0.97{\pm}0.04g\;C\;m^{-2}\;d^{-1}$). In addition, macroalgal vegetation showed the highest daily NEP ($3.31{\pm}0.45g\;C\;m^{-2}\;d^{-1}$) due to its highest P : R ratio (2.33). Furthermore, the eelgrass beds acted as a $CO_2$ sink through the air-seawater interface according to NEE data, with a carbon sink rate of $0.63mg\;C\;m^{-2}\;d^{-1}$. Overall, ecosystem production was found to be extremely high in the vegetated systems (eelgrass and macroalgal beds), which occupy a relatively small area compared to the unvegetated systems according to our conceptual diagram of a carbon-flux box model. These results indicate that the vegetative ecosystems showed significantly high capturing efficiency of inorganic carbon through coastal primary production.

Real-Time Hybrid Shaking Table Test of a Soil-Structure Interaction System with Dynamic Soil Stiffness (동적 지반강성을 갖는 지반-구조물계의 실시간 하이브리드 진동대 실험)

  • Lee, Sung-Kyung;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.2
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    • pp.217-225
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    • 2007
  • This paper proposes the real-time hybrid shaking table testing methods to simulate the dynamic behavior of a soil-structure interaction system with dynamic soil stiffness by using only a structure model as the physical specimen and verifies their effectiveness for experimental implementation. Experimental methodologies proposed in this paper adopt such a way that absolute accelerations measured from the superstructure and shaking table are feedback to the shaking table controller, and then the shaking table is driven by the calculated motion of the absolute acceleration (acceleration feedback method) or the absolute velocity (velocity feedback method) of foundation that is required to simulate the dynamic behavior of a whole soil-structure interaction system. The shaking table test is implemented by reflecting the dynamic soil stiffness, which are differently approximated from the theoretical one depending on the feedback methods, on the shaking table controller to calculate soil part. The effectiveness of the proposed experimental methods is verified by comparing the response measured from the test on a foundation-fixed structural model and that obtained from the experiment of a soil-interaction system under the consideration in this paper and by matching the dynamic soil stiffness reflected on the shaking table controller with that identified using the experimentally measured data.

Does College Experience Effect Job Quality Of Science And Engineering Graduates? -Focusing On Gender Gap (이공계 대학생의 대학생활 경험과 취업의 질 : 성별차이를 중심으로)

  • Shin, Ha-young;Moon, Bo-Eun
    • Journal of Engineering Education Research
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    • v.20 no.5
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    • pp.59-73
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    • 2017
  • This study aims to examine whether a gender works to make the difference on the university experiences of natural sciences and engineering major students; and the income and quality gap between the graduates. In this study, university experiences means job market and job searching related experiences such as job fair attending, The main research questions are as follows; fist, what are the significant university experiences related job preparation and application, and is there a gender gap on those experiences? Second, how is the job market performance of the national sciences and engineering graduates for their income level and quality job, and is there a gender gap on the job market performance of the sample? Third, which variables among the university experiences for job searching and application impacts the job quality and income level of the natural sciences and engineering graduates? To find out the research results, this study conducts a panel data analysis with GOMS (Graduates Occupational Mobility Survey) throughout survey year of 2006 to 2015, towards 568,264 as weighted value number. As analysis methods, this study carries out a descriptive analysis, ANOVA, discriminant analysis, linear regression and T-test. Therefore, here are the brief outputs of the study; first, for natural sciences and engineering students, the off-campus experiences such as job fair, job recruit festival and internship programs are more favored; second, female students are more likely to attend personal and self-driven job preparation programs; third, on job market performance, the graduates' income level and company scale rate are higher in the male but job stability is higher in the female; fourth, as a result of the linear regression, gender factor decides the income level in considerable degree; additionally, gender factor shows the difference of the job satisfaction and self-effectiveness on one's job as a qualitative variables. For obtaining strictness, university program factors are controlled through model fitness process. As above, this study finds out the main factors of university life of natural sciences and engineering graduates which are related their job searching and preparation experiences and figures out stronger factors in job market; and examines the statistically significance of the gender in this casual-effect relationship between job preparation and job quality of the graduates.

Meat Quality and Volatile Flavor Traits of Duroc, Berkshire and Yorksire Breeds

  • Dashmaa, Dashdorj;Cho, Byung-Wook;Odkhuu, Ganbat;Park, Kyoung-Mi;Do, Kyoung-Tag;Lee, Ki-Hwan;Seo, Kang-Seok;Choi, Jae-Gwan;Lee, Moon-Jun;Cho, In-Kyung;Ryu, Kyeong-Seon;Jeong, Da-Woon;Hwang, In-Ho
    • Food Science of Animal Resources
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    • v.31 no.6
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    • pp.807-816
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    • 2011
  • The present study evaluated the difference in objective and subjective meat quality properties among the pure-breed boars of Duroc, Berkshire and Yorkshire. Ten longissimus lumborum (LD) muscles were collected from each breed after 24 h slaughtering. The breed type showed a significant effect on intramuscular fat content, moisture (p<0.01), pH, sarcoplasmic protein solubility and color (p<0.05), whereas cooking loss and Warner Blazer shear force (WBsf) did not differ among the breeds. The Yorkshire breed showed significant (p<0.05) lower sarcoplasmic protein solubility, pH and CIE $a^*$ value when compared with other breeds. The sensory panels identified Duroc as having greater overall acceptability and higher rating values than other breeds. The oleic acid content was significantly lower in the Berkshire (29.85 %) than in the Duroc (40.19 %) and Yorkshire breeds (38.18 %, p<0.05). The Yorkshire breed showed the most desirable ratio of polyunsaturated and saturated fatty acids (0.31) than the Berkshire (0.16) and Duroc breeds (0.15, p<0.05). 40 volatile compounds have been identified and quantified, while aldehydes were the most abundant among flavor substances. Aldehydes were negatively correlated with oleic acid content (p<0.05). Current data indicated that each breed had their own merits and deficiencies in terms of meat qualityThe Yorkshire breed showed a greater number of weak points. Furthermore, this study indicated that individual fat-driven flavor components were greatly influenced by fatty acid composition. The polyunsaturated fatty acids did not show any negative effects on meat flavor if cooked meats were consumed soon after cooking.