• Title/Summary/Keyword: Before and after studies

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Study on Air Logistics Service Provider's Performance Under Post Covid19 Situation: Focusing on Trust and Reciprocity (포스트 코로나 시대의 항공물류 서비스기업의 경영성과에 대한 연구: 신뢰 및 호혜 개념을 중심으로)

  • Moon, Myungjoo;Koh, InKon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.3
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    • pp.135-145
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    • 2022
  • Due to COVID 19, we are facing unprecedented phenomena. Among various industries, the aviation industry, as it is directly affected by the corona crisis is actively establishing various survival strategies, such as expanding cargo transportation. The market size of air cargo transportation is continuously increasing due to the characteristics that distinguish it from other transportation, and as individualism and selfishness deepen in the aftermath of COVID 19, it can be inferred that the concept of reciprocity within distribution channels will become important in the post-corona era. The specific contents of this study(research question) are as follows. First, as a central member of the air logistics distribution channel, logistics service companies business process and the sub-dimensions of trust of are identified, and how trust is built with transportation companies is investigated. Second, the effect of such trust on the various performances of logistics service companies is analyzed. Third, we examine whether the influences of the sub-dimensions of trust change according to the perceived reciprocity of logistics service companies. In addition, we investigate whether the perceived reciprocity changed before and after the corona situation. In particular, this study theoretically integrates the concepts of trust and commitment, which have been distinguished in many prior studies, to improve the parsimony and practicality of the research model. This study will be able to present useful academic and practical implications by empirically examining how trust is built between members of the air logistics distribution channel and furthermore, how much it affects the performance of logistics service companies, and by identifying the moderating effect of reciprocity.

The Visitors Characteristics of Urban Ecological Park - The Cases of Gildong Ecological Park, Yeouido Tributary Ecological Park - (도시 생태공원 이용자 특성 연구 - 길동생태공원, 여의도샛강생태공원을 사례로 -)

  • Kim, Eun-Young;Lee, Jung-A;Kim, Hyoung-Gon;Chon, Jin-Hyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.1
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    • pp.64-74
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    • 2014
  • Ecological parks enable the sustainable use of natural resources and can be used as a place for site based environmental education. This study presented an opportunity to expand the scope of user perceptions and leisure benefits into urban ecological parks. However, in-depth studies which are aimed at eco-park visitors seeking the leisure benefits of the eco experience programs are lacking. The primary purpose of this study was to examine the urban ecological park user' characteristics which were derived by analyzing the leisure benefits and attitudes for the environment. Also, the attitudes about the environment, and the leisure benefits of visiting urban ecological parks was found to influence visitors' overall satisfaction. To accomplish the purposes of this study, a questionnaire survey with 282 samples was carried out on the urban ecological park(Gildong ecological park, Yeouido tributary ecology park). The results of the analyses are as following: urban ecological park visitors had a positive attitude about the environment, and felt satisfied by the visitors' leisure benefits. The study also examined the relationships between visitors' expectations of the leisure benefits both before visiting and after visiting. The results showed that ecological park visitors had greater expectations regarding the leisure benefits of the ecological program. Leisure benefits have a positive influence on overall satisfaction, and a positive attitude for the environment does not affect satisfaction. This study reaches the conclusion that the ecology experience program utilizing ecological parks is very effective with regard to overall satisfaction in urban areas toward the general environment and ecological parks. One of the major implications of this study is to offer a way to improve user leisure benefits and promote ecological programs by developing ecological parks for the future.

Development and Application of Scientific Inquiry-based STEAM Education Program for Free-Learning Semester in Middle School (중학교 자유학기제에 적합한 과학 탐구 중심의 융합인재교육 프로그램 개발 및 적용)

  • Jeong, Hyeondo;Lee, Hyonyong
    • Journal of Science Education
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    • v.41 no.3
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    • pp.334-350
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    • 2017
  • The purposes of this study are to develop scientific-inquiry based on STEAM education program and to investigate the effects of the program on middle-school students' interests, self-efficacy, and career choice about science, technology/engineering, and mathematics. In order to develop this program, the literature investigation and previous studies were conducted, so that finally the developmental direction was based on scientific inquiry and the developmental theme and model were selected. A total 92 first-graders in G middle-school of Daegu city were participated in this study. A single group pre-post test paired t-test was conducted to figure out changes of students' interest, self-efficacy, and career choices before or after applying this program. In addition, in-depth interviews were conducted with 14 students to find their specific responses. The results of this study were as follows. First, STEAM education program on the theme of 'RC Airplane' was developed on the basis of the 'ADBA' model. Second, the developed STEAM educational program not only results a decisive difference statistically but also has significant effects on middle-school students' interests, self-efficacy, and career choice in science, technology/engineering, and mathematics, who are involved in the free-semester program, across the overall affective domain. In conclusion, the STEAM educational program in this study could affect significant meanings to middle-school students during the free-semester. It could contribute to facilitate middle-school students' education for happiness and to grow the creative STEAM talents.

Analysis on the Effect of Lessons with the GIS Application in Teaching and Learning of Geography of Elementary School (초등학교 지리학습에 있어서 GIS 활용수업의 효과분석)

  • Park, Soon-Ho;Jung, Eun-Ju
    • Journal of the Korean association of regional geographers
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    • v.14 no.3
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    • pp.269-278
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    • 2008
  • This research analyzed the effect of lessons with the GIS application as an alternative scheme of teaching and learning of geography in elementary school. Two classes in the third grade at Y elementary school in Andong were selected to conduct lessons on 'The Landscape of My Hometown' from March 6 through June 30, 2006. In the experimental class, the lessons were conducted with the GIS application; while, in a comparative class, the lessons were carried with usual teaching and learning method. To find out the effect of lessons with the GIS application, differences of spatial cognition of students were figured out between groups, and before and after lessons. The difference between the spatial concept development stages and materials on the textbook discouraged students to pursue their learning as well as made them hard to achieve the goals of lessons. The GIS application had been suggested as an alternative teaching and learning method to overcome the difference; however, it has been hard to find any empirical research to verify the effect of the lessons with GIS application in elementary school. The ability of spatial cognition of the third graders at an elementary school was very low as the result of that curricula in the first and second grades dealt with sketch maps as teaching and learning media. The map learning of third grader on the transitional stage would play the critical role to develop the spatial cognition ability in the future. The field study contributing to developing spatial cognition ability would not be conducted at school. It was required to have the alternative learning schemes such as lessons with GIS application. The lessons with GIS application verified effect of GIS application as the alternative method. The GIS application helped students to recognize landmarks, directions and distance effectively as well as reduced the spatial cognition difference among individuals and/or groups.

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Percutaneous Cardiopulmonary Support (PCPS) for Patients with Cardioppulmonary Bypass Weaning Failure during Open Heart Surgery (개심술 중 심폐기 이탈에 실패한 환자에게 적용한 경피적 심폐순환 보조장치)

  • Ryu, Kyoung-Min;Park, Seong-Sik;Seo, Pil-Won;Ryu, Jae-Wook;Kim, Seok-Kon
    • Journal of Chest Surgery
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    • v.42 no.5
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    • pp.604-609
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    • 2009
  • Background: Recently, percutaneous cardiopulmonary support (PCPS) has been widely used to rescue patients in cardiogenic shock or cardiac arrest. However, patients with cardiopulmonary bypass (CPB) weaning failure during open heart surgery still have very poor outcomes after PCPS. We investigated clinical results and prognostic factors for patients who underwent PCPS during open heart surgery. Material and Method: From January 2005 to December 2008, 10 patients with CPB weaning failure during open heart surgery underwent PCPS using the CAPIOX emergency bypass system ($EBS^{(R)}$, Terumo Inc, Tokyo, Japan). We retrospectively reviewed the medical records of those 10 patients. Result: The average age of the patients was $60.2{\pm}16.5$ years (range, $19{\sim}77$ years). The mean supporting time was $48.7{\pm}64.7$ hours (range, $4{\sim}210$ hours). Of the 10 patients, 6(60%) were successfully weaned from the PCPS While 5 (50%) were able to be discharged from the hospital. Complications were noted in 5 patients (50%). In univariate analysis, long aortic cross clamp time during surgery, mediastinal bleeding during PCPS and high level of Troponin-I before PCPS were significant risk factors. All of the discharged patients are still surviving $34{\pm}8.6$ months (range, $23{\sim}48$ months) post-operatively. Conclusion: The use of PCPS for CPB weaning failure during open heart surgery can improve the prognosis. More experience and additional clinical studies are necessary to improve survival and decrease complications.

Personalized Exhibition Booth Recommendation Methodology Using Sequential Association Rule (순차 연관 규칙을 이용한 개인화된 전시 부스 추천 방법)

  • Moon, Hyun-Sil;Jung, Min-Kyu;Kim, Jae-Kyeong;Kim, Hyea-Kyeong
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.195-211
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    • 2010
  • An exhibition is defined as market events for specific duration to present exhibitors' main product range to either business or private visitors, and it also plays a key role as effective marketing channels. Especially, as the effect of the opinions of the visitors after the exhibition impacts directly on sales or the image of companies, exhibition organizers must consider various needs of visitors. To meet needs of visitors, ubiquitous technologies have been applied in some exhibitions. However, despite of the development of the ubiquitous technologies, their services cannot always reflect visitors' preferences as they only generate information when visitors request. As a result, they have reached their limit to meet needs of visitors, which consequently might lead them to loss of marketing opportunity. Recommendation systems can be the right type to overcome these limitations. They can recommend the booths to coincide with visitors' preferences, so that they help visitors who are in difficulty for choices in exhibition environment. One of the most successful and widely used technologies for building recommender systems is called Collaborative Filtering. Traditional recommender systems, however, only use neighbors' evaluations or behaviors for a personalized prediction. Therefore, they can not reflect visitors' dynamic preference, and also lack of accuracy in exhibition environment. Although there is much useful information to infer visitors' preference in ubiquitous environment (e.g., visitors' current location, booth visit path, and so on), they use only limited information for recommendation. In this study, we propose a booth recommendation methodology using Sequential Association Rule which considers the sequence of visiting. Recent studies of Sequential Association Rule use the constraints to improve the performance. However, since traditional Sequential Association Rule considers the whole rules to recommendation, they have a scalability problem when they are adapted to a large exhibition scale. To solve this problem, our methodology composes the confidence database before recommendation process. To compose the confidence database, we first search preceding rules which have the frequency above threshold. Next, we compute the confidences of each preceding rules to each booth which is not contained in preceding rules. Therefore, the confidence database has two kinds of information which are preceding rules and their confidence to each booth. In recommendation process, we just generate preceding rules of the target visitors based on the records of the visits, and recommend booths according to the confidence database. Throughout these steps, we expect reduction of time spent on recommendation process. To evaluate proposed methodology, we use real booth visit records which are collected by RFID technology in IT exhibition. Booth visit records also contain the visit sequence of each visitor. We compare the performance of proposed methodology with traditional Collaborative Filtering system. As a result, our proposed methodology generally shows higher performance than traditional Collaborative Filtering. We can also see some features of it in experimental results. First, it shows the highest performance at one booth recommendation. It detects preceding rules with some portions of visitors. Therefore, if there is a visitor who moved with very a different pattern compared to the whole visitors, it cannot give a correct recommendation for him/her even though we increase the number of recommendation. Trained by the whole visitors, it cannot correctly give recommendation to visitors who have a unique path. Second, the performance of general recommendation systems increase as time expands. However, our methodology shows higher performance with limited information like one or two time periods. Therefore, not only can it recommend even if there is not much information of the target visitors' booth visit records, but also it uses only small amount of information in recommendation process. We expect that it can give real?time recommendations in exhibition environment. Overall, our methodology shows higher performance ability than traditional Collaborative Filtering systems, we expect it could be applied in booth recommendation system to satisfy visitors in exhibition environment.

Forming and Changing the Concept of 'Cultural Property' before the Enactment of the Cultural Heritage Protection Act (문화재보호법 제정 이전 '문화재' 개념의 형성과 변화)

  • OH Chunyoung
    • Korean Journal of Heritage: History & Science
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    • v.56 no.4
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    • pp.288-318
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    • 2023
  • This work began with the aim of examining the history of the concept "cultural property" that is expected to disappear, and the main subject of research was the history that preceded the spread of this notion throughout society. The phrase "cultural property" first appeared in the 1920s, and was used in various fields such as literature, history, music, and philosophy in the context of cultural resources. Until immediately following liberation from the Japanese colonial era, the meaning of cultural assets was widely applied in the range of "cultural resources," and during this period, it was often used to help supplant the reality and history of Japanese occupation. Immediately after the Korean War, it was also employed for the purpose of 'restoration of cultural resources through war'. Recognition of cultural property directly influenced by Japan's Cultural Heritage Protection Act has occurred since 1950s. In the early 1960s, the enactment of various laws related to cultural properties and the establishment of the Cultural Heritage Administration caused the meaning of cultural property to be limited to 'cultural heritage'. In this way, the definition of state-led cultural property has continued to apply to this day. It has not been clearly confirmed whether the concept of cultural properties was imported from Japan through means such as the Cultural Heritage Protection Act. Cases in which several Japanese students endorsed the concept of cultural property within Korea serve to increase the likelihood that the concept was indeed imported from Japan. However, "coined language using multiple Chinese characters," "the phenomenon of cultural complex words in the 1920s,", and "cases of non-Japanese international students using the concept of cultural property" also open up the possibility of their own occurrence. Apart from the general importance of the concept of cultural property, intellectuals at the time used this concept to promote internal development and the overcoming of colonial Joseon. In this research, it was confirmed that the conceptual word cultural property was older and had a wider history than the general perception had indicated previously. The history of the conceptual term "cultural property" may appear to be more than 60 years old based on the enactment of the Cultural Heritage Protection Act, but in fact it is nearly 100 years old when traced back to on 1925, as established here. In general, the creation and disappearance of terms may proceed naturally with social change, but such terms may alternatively be created or erased through national policy. Identifying the origins of a phrase that is about to disappear represents a significant task for purposes of establishing its historical meaning.

A Comparative Study On Accident Prediction Model Using Nonlinear Regression And Artificial Neural Network, Structural Equation for Rural 4-Legged Intersection (비선형 회귀분석, 인공신경망, 구조방정식을 이용한 지방부 4지 신호교차로 교통사고 예측모형 성능 비교 연구)

  • Oh, Ju Taek;Yun, Ilsoo;Hwang, Jeong Won;Han, Eum
    • Journal of Korean Society of Transportation
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    • v.32 no.3
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    • pp.266-279
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    • 2014
  • For the evaluation of roadway safety, diverse methods, including before-after studies, simple comparison using historic traffic accident data, methods based on experts' opinion or literature, have been applied. Especially, many research efforts have developed traffic accident prediction models in order to identify critical elements causing accidents and evaluate the level of safety. A traffic accident prediction model must secure predictability and transferability. By acquiring the predictability, the model can increase the accuracy in predicting the frequency of accidents qualitatively and quantitatively. By guaranteeing the transferability, the model can be used for other locations with acceptable accuracy. To this end, traffic accident prediction models using non-linear regression, artificial neural network, and structural equation were developed in this study. The predictability and transferability of three models were compared using a model development data set collected from 90 signalized intersections and a model validation data set from other 33 signalized intersections based on mean absolute deviation and mean squared prediction error. As a result of the comparison using the model development data set, the artificial neural network showed the highest predictability. However, the non-linear regression model was found out to be most appropriate in the comparison using the model validation data set. Conclusively, the artificial neural network has a strong ability in representing the relationship between the frequency of traffic accidents and traffic and road design elements. However, the predictability of the artificial neural network significantly decreased when the artificial neural network was applied to a new data which was not used in the model developing.

Studies on the Effects of Temperature During the Reduction Division and the Grain Filling Stage in Rice Plants I. Effect of Temperature at the Reduction Division Stage in Indica-Japonica Crosses (수도의 감수분열기 및 등숙기에 있어서 온도반응에 관한 연구 제1보 수도 indica $\times$ Japonica품종의 감수분열기에 있어서의 저온의 영향)

  • Kim, Kyu-Chin
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.1
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    • pp.41-57
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    • 1983
  • The effect of temperature 'during the reduction division stage on the Indica-Japonica rice varieties were studied in artificial temperature-controlled cabinets (Bioclimatic Laboratory). Varieties used were indica-japonica crosses (Suweon 264, Suweon 258, Milyang 29), indica (IR36, Lengkwang) and japonica rice (Jin-heung). The results obtained from this study are summarized as follows. The most sensitive stage to low temperature, the tetrad stage, was observed in each variety with the following auricle distance: Jinheung, -12cm; IR36, -3cm; Suweon264, -9cm; Suweon258, -3cm; Milyang29, -6cm and Lengkwang, +1cm. The tetrad stage occured when the palea elongation was about 50 to 60% of the final palea length at flowering stage in all varieties. The percentage of degenerated spikelets at tetrad as influenced by low-temperature treatment was very low in Jinheung and Lengkwang, but very high in IR36. In indica-japonica crosses only the 7-days treatments had a very high percentage. Between the 4-day and 7-day treatments as well as among all varieties, clear differences were observed in the low temperature induced sterility of 'special spikelets' (upper position grains at tetrad). In the 7-day treatments except in Lengkwang, all varieties showed very high sterility. It appears that the treatments is over the critical limit for treatment. However in the 4-day treatments, the intervarietal differences in sterility were very clear. In Jinheung, sterility was 46.8%; IR36, 67.6%; Suweon264, 60.9%, Milyang29, 62.2%; Lengkwang, 27.8%. A close relationship was observed between fertility and auricle distance. The lowest fertility of special spikelets was at the tetrad stage and the first contraction phase. Before and after the stage there was an increase in fertility. The palea length elongated nearly in a straight line from the spikelet formation stage to flowering. And there was a high correlation between palea length and auricle distance. distance.

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Studies on the Hydrolysis of the Waste wood of Cortinellus edodes with Trichoderma viride Cellulase (표고재배폐재(栽培廢材)의 당화(糖化)에 관(關)한 연구(硏究))

  • Min, Du Sik
    • Journal of Korean Society of Forest Science
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    • v.43 no.1
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    • pp.31-34
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    • 1979
  • In this study, enzymatic hydrolysis of the substrate of the waste wood of Cortinellus edodes was investigated using crude cellulase preparation of Trichoderma viride Pers. ex. Fr. SANK 16374. The crude cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. Reducing sugar was determined by the dinitrosalisylic acid (DNS) method. 1. The chemical composition of the waste wood was crude protein 2.26%, c. fat 2.57%, c. fibre 44.60%, c. ash 5.58% and lignin 13.62%. In amino acid composition, no cystine and methionine was showed, but trace amount of Vitamin A, $B_1$, and $B_2$, niacine and chloride were detected. (Table 1) 2. As heat treatment of the substrate was found to produce the highest reducing sugar yield being reacted for 48hr. with T.v cellulase, the substrate was heated to $190{\pm}5^{\circ}C$. for 45 min. either before or immediately after milling. 3. The substrate heated and ball milled at $190{\pm}5^{\circ}C$. for 45 min. the reducing sugar yield reached to 11.5%. 4. The substrate without any treatment was found to produce the highest reducing sugar yield being reacted 72hr. with T. v cellulase, the reducing sugar yield reached to 10.1%. 5. The rate of reducing sugar per each treated substrate was decreased by the order of the substrated, heated and then ball milled at $190{\pm}5^{\circ}C$. for 45 min. (11.5%)> without any treatment (10.1)> ball milled and heated at $190{\pm}5^{\circ}C$. for 45 min. (6.9%). 6. Saccharification of waste wood has been shown to be possible by heat treated and milling the substrate in contact with cellulase. And it is likely to be recommended that the waste wood may be valuable for raw materials of saccharification.

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