• 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) ].

• 한국안광학회지
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• 제21권1호
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• pp.35-45
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• 2016

목적: 본 연구에서는 토릭소프트콘택트렌즈를 일정시간 착용했을 때와 응시방향을 달리하였을 때 각막이심률이 축 회전에 미치는 영향에 대해서 알아보고자 하였다. 방법: 이중쐐기형 축 안정화 디자인을 가진 토릭소프트콘택트렌즈를 85안의 직난시안에 착용시키고 착용 15분 후와 6시간 후에 각각 응시방향에 따른 회전방향 및 회전양 변화를 측정하고 각막이심률에 따른 차이가 나타나는 지 비교분석하였다. 결과: 토릭소프트콘택트렌즈의 회전은 착용 15분 후와 6시간 후 모든 각막이심률 군에서 귀-위쪽방향으로의 응시를 제외하고 모두 귀쪽으로 회전하는 경향이 있었다. 정면주시할 때의 회전양은 착용 15분 후와 6시간 후 모두 각막이심률이 증가할수록 회전양이 감소하는 음의 상관관계를 나타내었으며, 이심률이 작은 각막에서는 $10^{\circ}$ 이상의 회전을 보이는 경우가 많았다. 토릭소프트콘택트렌즈 착용 15분 후의 회전양은 각막이심률에 따른 차이가 적었으나, 착용 6시간 후에는 각막이심률에 따라 회전양의 변화 정도에 차이가 나타났다. 결론: 본 연구에서는 토릭소프트콘택트렌즈 착용 시 각막이심률에 따라 축 회전양이 크게 달라지며 일정시간 착용 후의 회전양 또한 각막이심률에 영향을 받음을 밝혔다. 따라서 각막이심률에 따라 적절한 토릭소프트콘택트렌즈의 선택이 필요함을 제안한다.

• Restorative Dentistry and Endodontics
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• 제12권1호
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• pp.25-37
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• 1986

This study was undertaken to measure the diffusibility and antimicrobial effectiveness of the medication used in clinical practice. To study the diffusibility of the root canal medicament, loss of formocresol and camphorated phenol from a cotton pellet after insertion into the pulp chamber of 260 molars prepared as routine endodontic treatment was measured. Measurement was done for the one time insertions and for the reinsertions using ultraviolet spectrophotometer. Antibacterial effectiveness against three microoganisms, Staphylococcus aureus, Staphylococcus epidermidis and a-hemolytic streptococcus, on the blood agar plate was observed by measurement of the inhibition zone with. various amount of medicaments. The following results were observed. 1. Nearly all of the medication were lost in the first day after insertion and the residual amount of camphorated phenol was greater than that of formocresol. 2. Residual amounts of medication in the reinsertion group were greater than that of the one time insertion group. 3. Within the pulp chamber diffusibility of formocresol was greater than that of camphorated phenol. 4. The amount of formocresol diffusing out from the tooth was greater than that of camphorated phenol. 5. Antibacterial effectiveness was observed from the residual amount of formocresol in the reinsertion group and in other groups no antibacterial effectiveness was observed.

• 보건행정학회지
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• 제27권1호
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• pp.39-46
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• 2017

Background: We evaluated new patient's satisfactory consultation time (SCT) and their willingness to pay additional costs (WPAC) for their SCT. Methods: We surveyed medical service satisfaction, SCT, WPAC for their SCT, and payable amount to 612 new patients of single general hospital and measured their real consultation time (RCT). To compare WPAC and payable amount, we divided RCT into 4 groups (${\leq}3$ minutes, 3-5 minutes, 5-10 minutes, and > 10 minutes), and SCT into 3 groups (${\leq}5$ minutes, 5-10 minutes, and > 10 minutes). On the basis of WPAC, we estimated new patient's SCT. Results: RCT was 6.2 minutes, SCT was 8.9 minutes, and medical service satisfaction score was 4.3 (out of 5). The number of patients having WPAC (payable group) was 381 (62.3%) and the amount was 5,853 Korean won. Their RCT and SCT were longer than non-payable group (6.4 minutes vs. 5.7 minutes, 9.3 minutes vs. 8.2 minutes). From multiple logistic regression analysis, WPAC of RCT 5-10 minutes was higher than that RCT ${\leq}3$ minutes (odds ratio= 1.78). Payable amount was highest in RCT > 10 minutes (6,950 Korea won) and SCT > 10 minutes (7,458 Korean won). Intuitively we suggest 10 minutes as SCT, based on payable group's SCT (9.3 minutes) and cut-off time differentiating payable group with non-payable group (10 minutes). Conclusion: We found that new patient had WPAC for their SCT and the longer the SCT, the greater the amount. From this, we hope that current simplified new patient consultation fee calculating system should be modified combining the consultation time factor.

• 한국산업융합학회 논문집
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• 제24권3호
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• pp.295-300
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• 2021

This study investigated the dominant frequency of the elastic waves from the tensile test. The specimen was rolled with five different rolling degrees (10, 22, 33, 42 and 50%), which was treated subzero. The specimen was rolled at room temperature, which was transformed from austenite to martensite (only α'-martensite). The dominant frequency increased with an increase in the rolling degree regardless of the subzero temperature, and decreased after 33% of the rolling degree. On the other hand, higher frequency band was obtained at lower temperature and long time. The dominant frequency increased when the amount of α'-martensite increased and decreased with the α'-martensite amount between 50-65%. The lower subzero treatment temperature increased the amount of α'-martensite, which resulted in the higher dominant frequency. The longer treatment time at the same subzero temperature led to an increase in the amount of α'-martensite, leading to high dominant frequency.

• Elastomers and Composites
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• 제14권1호
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• pp.7-12
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• 1979

Graft copolymerization of methlymethacrylate(MMA) onto sodium alginate(SA) aqueous solution by sodium metaperiodate$(NaIO_4)$ as an initiator was carried out with the variation of the reaction time, the reaction temperature and the concentrations of initiator and monomer. The results obtained were as follows: 1. SA was easily separated from the reaction mixture of homopolymer, graft polymer and sodium alginate ungrafted by the treatment of concentrated boiling $Na_3PO_4$, solution with the small amount of $Na_2SO_3$ to the mixture and then isolated as the acid form by acidifying the salts solution containing SA. 2. The amount of graft polymer was larger than that of homopolymer below $70^{\circ}C$ whereas above $70^{\circ}C$ the amount of homopolymer was larger. 3. The sum of each amount of graft polymer ana homopolymer was always increased with increase of the reaction time, the reaction temperature and the concentrations of initiator and monomer. 4. With increase of the concentration of initiator, the graft efficiency was increased below $70^{\circ}C$ while decreased above $70^{\circ}C$. 5. Graft copolymerization of MMA onto SA in aqueous solution was carried out without initiator.

• KSBB Journal
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• 제28권4호
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• pp.249-253
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• 2013

In this study, we analyzed the attachment amount and the surface properties, such as shape and attachment aspect of silver nanoparticles on the surface of salt and sucrose. In addition, we investigated the antimicrobial activity of silver nanoparticles by measuring total colony counts and total coliforms in sewage according to the time and the amount of silver nanoparticles. As a result, it is found that silver nanoparticles are attached on the surface of salt and sucrose from the SEM images and there is no microorganisms on the surface of salt and sucrose. Silver nanoparticles on salt were rod shape but silver nanoparticles on sucrose were round shape. Also, the content of silver was 0.735 mg/g on salt and 0.885 mg/g on sucrose. In all experiments, total colony counts and total coliforms sharply declined initially, and it decreased gradually as change the time. When injection amount of nano silver sucrose and salt increased, the width of decline was greater. The amount of total colony counts and total coliforms of nano silver salt was much lower and the disinfection efficiency was higher comparing with nano silver sucrose. That means the case of nano silver salt is much better at the antimicrobial activity.

• Journal of Chest Surgery
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• 제33권7호
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• pp.560-564
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• 2000

배경; 아프로티닌(Aprotinin)은 nonspecific serine protease inhibitor로 개심술에서 항염효과와 혈액 응고효과를 갖고 있다. 또한 아프로티닌은 심폐기 작동 중에는 항트롬빈(antithrombin) 효과가 있다. 본 연구는 아프로티닌이 헤파린(heparin)사용 양 및 ACT(activated clotting time) 에 어떠한 영향을 미치는 가를 알아보기 위하여 시행하였다. 대상 및 방법; 1998년 12월 1일부터 1999년 11월 30일 까지 본원에서 개심술을 받은 환자 중 연령이 18세 이상인 82명을 대상으로 연구하였다. 환자들은 아프로티닌을 사용한 군(Group A)과 사용하지 안흥ㄴ 군(Group C)으로 나누어 연구하였다. 모든 환자에서 수술 전 체중, 신장, 체표면적, pump time, ACC time 등을 조사하였다. ACT의 측정 시기는 헤파린 공급 전, 공급 후 20분, 40분, 60qs과 프로타민 공급 후 20분 등이었다. 또한 ACT 변화 정도를 알아보기 위하여 헤파린 공급 전과 공급 후 20분, 공급 후 40분과 20분 사이의 차이를 조사하였다. 결과; 연구 대상 환자들이 굴변 특징에서는 연령, 펌프시간 및 대동맥차단 사간에서 모두 A군에서 증가된 소견을 보였다. (p<0.05). 헤파린 공급 전과 프로타민 공급 후의 ACT는 두 군에서 차이가 없으며 헤파린 공급 후 20분(607$\pm$22.3, 525$\pm$169초), 40분(889$\pm$315, 546$\pm$103초), 60분 (748$\pm$310, 472$\pm$115 초)에 측정한 ACT는 모두 A군에서 증가된 소견을 보였다. (p<0.05), 헤파린 공급 전과 궁급 후 20분 사이의 ACT 차이는 A한 군에서 증가된 소견을 보였고(p<0.05), 헤파린 공급 후 40분과 20분 사이의 ACT의 차이 또한 A군에서 증가된 소견을 보였다. (p<0.05). 두 군간의 총 헤파린 및 프로타민 사용 양에는 차이가 없었다. (p>0.05). 결론; 결론적으로 아프로티닌은 본 연구에서 CPB time을 고려해 볼 때 헤파린사용 양을 의미있게 줄여 줄 수 있을 것으로 생각되며 또한 ACT를 증가시켜 주기 때문에 추가적인 헤파린 감량이 가능할 것으로 생각된다.

• 융합경영연구
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• 제9권2호
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• pp.1-10
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• 2021

Purpose: In this work, we examine several time series models to predict internet and mobile transaction amount in South Korea, whereas Jeong (2020) has obtained the optimal forecasts for online shopping transaction amount by using time series models. Additionally, optimal forecasts based on the model considered can be calculated and applied to the Corona 19 situation. Research design, data, and methodology: The data are extracted from the online shopping trend survey of the National Statistical Office, and homogeneous and comparable in size based on 46 realizations sampled from January 2007 to October 2020. To achieve the goal of this work, both multiplicative ARIMA model and Holt-Winters Multiplicative seasonality method are taken into account. In addition, goodness-of-fit measures are used as crucial tools of the appropriate construction of forecasting model. Results: All of the optimal forecasts for the next 12 months for two online shopping transactions maintain a pattern in which the slope increases linearly and steadily with a fixed seasonal change that has been subjected to seasonal fluctuations. Conclusions: It can be confirmed that the mobile shopping transactions is much larger than the internet shopping transactions for the increase in trend and seasonality in the future.

• 가정과삶의질연구
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• 제33권3호
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• pp.1-14
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• 2015

This study examined the effects of Dream Start participation on the use of after-school programs, considering its emphasis on the utilization of community resources. For this, it compared the use of after-school programs in terms of the number of types and the total amount of time between children who had been participating in Dream Start and those who had not. The main findings are as follows. First, when all other conditions were held constant, children in Dream Start used more types of after-school programs compared to their correspondents. Second, children in Dream Start were more likely to use two types of after-school programs over weekdays or three types of programs for several days a week compared to their correspondents. Third, children in Dream Start spent less amount of time in the after-school programs compared to their correspondents. Even though this study found the effectiveness of Dream Start as a facilitator of community resource utilization, future research needs to examine the effects of after-school program use in terms of its diversity and amount on the development of low-income children.