• Asia pacific journal of information systems
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• 제32권3호
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• pp.514-536
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• 2022

Online reviews offer valuable information to businesses by reflecting consumer experiences about their products and services. Two crucial aspects of online reviews are the topics consumers choose to address, and the sentiments expressed in their reviews. Building upon previous literature that shows online reviews are context-dependent, we employ the Expectation-Confirmation Theory (ECT) to examine the impact of topic distribution on review sentiment in South Korea and the U.S. during pre- and post-pandemic periods. After applying a topic modeling to Airbnb app review data, we measure the contribution of each topic on review sentiment using SHAP values. Our results indicate variations in topic distribution trends between 2018 and 2021. In addition, the order and magnitude of topics' impact on review sentiment change between pre- and post-pandemic periods for both countries. This study can help businesses understand how topics and sentiments associated with their products and services changed after the pandemic and thus identify areas of improvement.

• 한국컴퓨터정보학회논문지
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• 제27권10호
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• pp.211-222
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• 2022

본 연구는 코로나 이전과 코로나 이후의 강의평가를 비교 분석하여, 코로나 이후 시대에 대학수업에서 고려해야 되는 사항은 무엇인지를 도출하고자 하였다. 이를 위해 서울시 소재 A대학의 4개년도 자료를 이용하였고, 코로나 이전은 2018년~2019년까지, 코로나 이후는 2020년~2021년까지 자료를 이용하였다. 연구결과에 의하면, 교양의 경우에는 "과제"가 코로나 이전과 이후와 상관없이 빈도 및 연결중심성(DC)이 가장 가장 높은 단어로 나타났으나, 전공에서는 "이해"가 가장 중요한 단어로 나타났다. 에코 네트워크의 분석결과, "동영상" 및 "비대면수업"의 경우에는 어렵다고 느끼고 있으며, 교수와 학생간의 "상호작용"이 중요하다고 생각하고 있었다. 결론적으로 코로나 이후의 교양 수업에서는 과제에 대한 비중을 낮추고, 학생과의 상호작용을 높이는 것이 중요하며, 전공의 경우에는 비대면 수업보다는 대면수업으로 운영하고, 동영상도 어렵지 않게 내용을 구성하는 것이 필요하다는 것을 확인하였다.

• 대한치과교정학회지
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• 제25권3호
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• pp.355-373
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• 1995

두개악안면 영역은 많은 해부학적 구조를 포함하는 근골격구조(musculodentos keletal system)로 두부골격의 구조, 악궁상태, 저작근의 형성 및 기능은 서로 밀접한 연관성을 가지고 있다. 두개악안면 영역의 성장과 발육은 유전적인 요인이외에 환경적인 요인들 즉, 두개안면부의 근육을 포함한 주위조직의 영향을 받는 것으로 이미 알려져 있다. 그러나 반대로 두개안면부의 골격구조가 변화되는 경우 이에 대응하여 두개안면근육의 기능 또한 변화, 적응되는지에 대해서는 체계적인 연구결과가 미흡한 상태이다. 저자는 골격형 제 III급 부정교합자의 악교정수술 전, 후의 근활성도의 변화에 대한 비교연구를 통해 두부 골격구조와 교합상태에 따른 저작근 기능의 상호관계 및 변화 양상에 대해 알아보고자 정상교합을 가진 성인남자 15명과 술전 및 술후 골격형 제 III급 부정교합자 각각 15명을 대상으로 측모두부 방사선사진과 저작효율검사 및 rest, clenching, chewing, swallowing시의 전측두근, 교근, 상순의 근활성도 검사를 시행하여 다음과 같은 결과를 얻었다. 1. 하악의 안정위(rest)에서 술전 부정교합군에서 술후군보다 전측두근, 교근, 상순에서 높은 활성도를 보였으며, 술후군에서는 상순에서만 정상대조군보다 의미있는 높은 근활성도를 보였다. 2. 최대교합(clenching)시는 술후군에서 술전 부정교합군보다 전측두근, 교근, 상순에서 높은 근활성도를 보였다. 3. 저작(chewing)시는 술후군이 술전 부정교합군보다 전측두근 및 교근에서 높은 활성을 보인 반면 상순에서는 감소된 근활성도를 보였다. 4. 연하(swallowing)시 술후군에서 상순은 술전 부정교합군보다 감소되었으나 정상대조군보다 증가된 근활성도를 나타냈으며, 각 군간에 전측두근 및 교근에서는 유의차가 없었다. 5. 저작효율은 술전부정교합군에서 정상대조군보다 낮았으며, 술후군에서 술전 부정교합군보다 증가되었으나 두군 모두 정상대조군과 유의차를 보였다.

• 동의생리병리학회지
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• 제20권5호
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• pp.1254-1260
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• 2006

The purpose of this study was to the Pre-Post submaximal exercise for analyze the Blood Lactate, LDH(Lactate Dehydrogenase) and Glucose in the runners. The subjects were 12 volunteers 6 sprinters and 6 distance runners who agreed to intention of this study. Subjects peformed until possible all-out trials. Blood samples were taken from a Ante cubital vein Pre-Post exercise and every rest 5min during the all-out trial. The results obtained were summarized as follow; 1) Blood Lactate of Pre-Post exercise in treadmill test showed no significant difference between sprinters and distance runners, but showed significant in sprinters and distance respectively. 2) Serum LDH of Pre-Post exercise in treadmill test showed no significant difference between sprinters and distance runners, and that showed no significant in sprinters and distance respectively. 3) Blood Glucose of Pre-Post exercise in treadmill test showed no significant difference between sprinters and distance runners, and showed no significant in distance, but showed significant in sprinters. These data indicate first that the value of 4mmol/${\ell}$, commonly referred to as OBLA(Onset of Blood Lactate),may often underestimate the upper limit of tolerance to lactate during a maximal endurance peformance test until all-out. second, our date suggested that the sprinters exercise decreases serum LDH activities and the distance increases serum LDH activities. therefore serum LDH concentration changed following a different exercise. Third. for the concentration of the glucose in blood the sprinters was show to be higher. However it needs more studies to find out the relationship between this result and the fitness factor. therefor, since the runners has an intermittent characteristic which includes a frequent momentary change, it needs the fitness training that being consisted of various training. in the training method, it needs the training process which is from the whole fitness to specific fitness to improve general physical ability.

• 한국건설관리학회논문집
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• 제13권5호
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• pp.25-34
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• 2012

본 연구는 주택 후분양제도를 도입한지 6년여 기간이 경과되는 현 시점에서 제도시행의 취지 및 효과를 점검하고, 공급자 관점에서 분양시기에 따른 수익성 변화를 분석하여 그 정도를 파악하였다. 서울시 공동주택 사업을 대상으로 사례분석 하였으며, 분양수입의 현재가치분석, 민감도분석, 분양가를 예측한 현재가치분석을 실시하였다. 분석결과 첫째, 선분양제가 후분양제보다 5.1%~6.2% 수익성이 높았고, 선분양의 4가지 안(착공후 즉시, 건설공정 20%, 40%, 60%) 가운데 착공과 동시에 계약금을 회수하는 안의 분양수입이 가장 높았다. 둘째, 할인율 증가와 분양수입 감소는 정비례하였으며, 할인율이 커질수록 공급자관점에서의 분양수입은 감소하였다. 셋째, 분양시기에 따른 분양가격 변동을 감안하여, 기본형건축비의 변동폭을 고려한 분양수입의 현재가치는 선분양방식이 후분양방식에 비해 2% 내외의 미미한 수준에서 다소 높았다. 본 연구는 분양시기에 따른 수익성을 공급자 관점에서 명확하게 계량화하여 제시하였고, 분양시기 변화에 따른 분양가 변동을 고려하여 분양수입을 산출하였다는 점에 의의가 있다.

• Journal of Trauma and Injury
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• 제34권2호
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• pp.87-97
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• 2021

Purpose: This study examined emergency medical service (EMS) transportation patterns for adult trauma patients before and after establishing a level 1 regional trauma center (RTC) and to evaluate the transportation approach after prehospital severity screening. Methods: This was a retrospective observational study of trauma patients aged ≥18 years admitted via EMS to the emergency department or a level 1 RTC, 1 year before to 3 years after RTC establishment. Patients with an Injury Severity Score (ISS) in the patient registration system were selected. Analyses were performed to determine transportation pattern changes by comparing patients pre- and post-RTC establishment and by yearly comparisons over the 4-year study period using the Mann-Whitney U test and chi-square test. Results: Overall, 3,587 patients were included. The mean ISS was higher in the post-RTC group (n=2,693; 10.63±8.90, median 9.00) than in the pre-RTC group (n=894; 9.44±8.20, median 8.00; p<0.001). The mean transportation distance (9.84±13.71, median 5.80 vs. 13.12±16.15 km, median 6.00; p<0.001) was longer in the post-RTC group than in the pre-RTC group. Furthermore, proportionally fewer patients were transported from an area in the same city as the RTC after establishment (86.1% vs. 78.3%; p<0.001). Yearly comparisons revealed a gradually increasing trend in the hospital death rate (ptrend=0.031). Conclusions: After establishing a level 1 RTC, the EMS transportation of severe trauma patients increased gradually along with the long-distance transportation of minor trauma patients. Therefore, improved prehospital EMS trauma severity assessments and level 1 RTC involvement in patient classification in the prehospital phase are necessary.

• 한국보육지원학회지
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• 제18권1호
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• pp.1-22
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• 2022

Objective: This study attempted to verify the effectiveness of parent education programs which emphasize parents' direct interaction with young children even when using digital devices. For this purpose, parents' play beliefs and their interaction with their children were evaluated by taking a pre-test and post-test. Methods: The subjects of this study were parents of young children attending child care centers. The collected data were analyzed by one-way covariate analysis (ANCOVA) to find out if there was a significant difference in post-test scores after controlling the pre-test as a covariate to minimize possible errors between groups before the experiment. Results: Parents, who had participated in the parent education program which emphasized parents' direct interaction with young children when using digital devices, showed higher increases of play support beliefs and parent-child interaction than the comparative group. Conclusion/Implications: This study confirmed that in order to develop digital fluency from early childhood, parents should avoid indiscriminate use of digital devices at home, maintain direct interaction with their children even when giving them digital devices to play with, and support healthy growth by way of continuing sensitive interaction with their children.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제34권2호
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• pp.161-177
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• 2020

본 연구는 고등학생을 대상으로 실험집단과 비교집단을 구성하고, 일대다(一對多) 튜토링 협동학습을 실시하였다. 집단 간 점수 차이와 집단별 사전·사후 점수 차이에 대한 유의성 검증은 비모수 통계기법을 사용하였으며, 학생들의 정의적 영역을 살펴보기 위하여 개방형 설문조사 2회와 개별 면담하였다. 실험집단과 비교집단 간 점수 차이는 통계적으로 유의하지 않았지만, 세 집단의 사전·사후 수학 점수 차이 검증 결과는 실험집단만 통계적으로 유의한 차이가 있었다. 그리고 학생교사는 일반학생을 가르치는 동안 자신을 성찰하고 자기효능감이 향상되었으며, 일반학생은 학생교사에게 도움을 받음으로써 수업에 대한 재미와 관심을 더 두게 되고 자신감이 향상되었다. 수학 교과 역량 측면은 의사소통, 문제해결, 추론, 태도 및 실천 역량이 향상되었음을 알 수 있었다.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 춘계학술대회
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• pp.675-690
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• 2004

A new way of teaching on the Internet can be called Web Based Instruction (WBI). WBI goes far above and beyond teaching in the school. It will have an impact on overall educational activity that will dramatically change many existing educational processes and persuade most teachers to change their conventional teaching methods. The main purposes of this research were to make a comparative study of academic achievement between expository lecture and web-based instruction, and to identify the difference in academic achievement of learning tasks in pre- and post- experiments of WBI. The conclusions of this study were as follows. First. there are no differences in academic achievement between expository lecture and teacher- directed web based instruction. Second, there are no differences in academic achievement between expository lecture and teacher-assisted web based instruction. Third, there is difference in academic achievement between teacher-assisted web based instruction and teacher-directed web based instruction. Fourth, there are no differences in academic achievement of reading tasks in pre- or post- experiments of teacher-directed web based instruction. On the basis of the research results and discussion, we finally present a Web-Application-Model (WAM) to encourage the usage of Internet as a useful teaching channel.

• 한국비블리아학회지
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• 제5권1호
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• pp.85-105
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• 1981

Information is an essential factor leading the rapid progress which is one of the distinguished characteristics in modem society. As more information is required and as more is supplied by individuals, governmental units, businesses, and educational institutions, the greater will be the requirement for efficient methods of communication. One possibility for improving the information dissemination process is to use computers. The capabilities of such machine are beginning to be used in the process of Information storage, retrieval and dissemination. An important problems, that must be carefully examined is whether one technique for information retrieval is better for worse than another. This paper examines problem of how to evaluate an information retrieval system. One specific approach is a cost accounting model for use in studying how to minimize the cost of operating a mechanized retrieval system. Through the use of cost analysis, the model provides a method for comparative evaluation between systems. The general cost accounting model of the literature retrieval system being designed by this study are given below. 1. The total cost accounting model of the literature retrieval system. The total cost of the literature retrieval system = (the cost per unit of user time X the amount of user time) + ( the cost per unit of system time X the amount of system time) 2. System cost accounting model system cost = (the pre-search system cost per unit of time X time) + (the search system cost per unit of time X time) + (the post search system cost per unit of time X time) 1) Pre-search system cost per unit of time = cost of channel per unit time + cost of central processing unit per unit time + cost of storage per unit time 2) Search system cost per unit of time = comparison cost + document representation cost. 3) Post-search system cost per unit of time. = cost of channel per unit time + cost of central processing unit per unit time + cost of storage per unit time 3. User cost accounting model Total user cost = [pre-search user cost per unit of time X (time + additional time) ] + [search user cost per unit of time X (time + additional time) ] + [post-search user cost per unit of time X (time + additional time) ].