• Title/Summary/Keyword: Cause of failure

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Weaning Following a 60 Minutes Spontaneous Breathing Trial (1시간 자가호흡관찰에 의한 기계적 호흡치료로부터의 이탈)

  • Park, Keon-Uk;Won, Kyoung-Sook;Koh, Young-Min;Baik, Jae-Jung;Chung, Yeon-Tae
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.3
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    • pp.361-369
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    • 1995
  • Background: A number of different weaning techniques can be employed such as spontaneous breathing trial, Intermittent mandatory ventilation(IMV) or Pressure support ventilation(PSV). However, the conclusive data indicating the superiority of one technique over another have not been published. Usually, a conventional spontaneous breathing trial is undertaken by supplying humidified $O_2$ through T-shaped adaptor connected to endotracheal tube or tracheostomy tube. In Korea, T-tube trial is not popular because the high-flow oxygen system is not always available. Also, the timing of extubation is not conclusive and depends on clinical experiences. It is known that to withdraw the endotracheal tube after weaning is far better than to go through any period. The tube produces varying degrees of resistance depending on its internal diameter and the flow rates encountered. The purpose of present study is to evaluate the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube. Methods: We analyzed the result of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube in 18 subjects from June, 1993 to June, 1994. They consisted of 9 males and 9 females. The duration of mechanical ventilation was from 38 hours to 341 hours(mean: $105.9{\pm}83.4$ hours). In all cases, the cause of ventilator dependency should be identified and precipitating factors should be corrected. The weaning trial was done when the patient became alert and arterial $O_2$ tension was adequate($PaO_2$ > 55mmHg) with an inspired oxygen fraction of 40%. We conducted a careful physical examination when the patient was breathing spontaneously through the endotracheal tube. Failure of weaning trial was signaled by cyanosis, sweating, paradoxical respiration, intercostal recession. Weaning failure was defined as the need for mechanical ventilation within 48 hours. Results: In 19 weaning trials of 18 patients, successful weaning and extubation was possible in 16/19(84.2 %). During the trial of spontaneous breathing for 60 minutes through the endotracheal tube, the patients who could wean developed slight increase in respiratory rates but significant changes of arterial blood gas values were not noted. But, the patients who failed weaning trial showed the marked increase in respiratory rates without significant changes of arterial blood gas values. Conclusion: The result of present study indicates that weaning from mechanical ventilation following a 60 minutes spontaneous breathing with $O_2$ supply through the endotracheal tube is a simple and effective method. Extubation can be done at the same time of successful weaning except for endobronchial toilet or airway protection.

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A comparative study on the correlation between Korean foods and the fractures of PFG and all ceramic crowns for posterior applications (구치용 도재소부금관과 전부도재관에 파절을 일으키는 한국음식에 관한 연구)

  • Kim, Jeong-Ho;Lee, Jai-Bong
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.2
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    • pp.156-163
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    • 2009
  • Statement of problem: Recently, there have been increased esthetic needs for posterior dental restorations. The failure of posterior dental ceramic restoration are possible not only by the characters of the component materials but also by the type of food. Purpose: The research aim was to compare the in vitro fracture resistance of simulated first molar crowns fabricated using 4 dental ceramic systems, full-porcelain-occlusal-surfaced PFG, half-porcelain-occlusal-surfaced PFG, Empress 2, Ice Zirkon and selected Korean foods. Material and methods: Eighty axisymmetric crowns of each system were fabricated to fit a preparation with 1.5- to 2.0-mm occlusal reduction. The center of the occlusal surface on each of 15 specimens per ceramic system was axially loaded to fracture in a Instron 4465, and the maximum load(N) was recorded. Afterwards, selected Korean foods specimens(boiled crab, boiled chicken with bone, boiled beef rib, dried squid, dried anchovy, round candy, walnut shell) were prepared. 15 specimens per each food were placed under the Instron and the maximum fracture loads for them were recorded. The 95% confidence intervals of the characteristic failure load were compared between dental ceramic systems and Korean foods. Afterwards, on the basis of previous results, 14Hz cyclic load was applied on the 4 systems of dental ceramic restorations in MTS. The reults were analyzed by analysis of variance and Post Hoc tests. Results: 95% confidence intervals for mean of fracture load 1. full porcelain occlusal surfaced PFG Crown: 2599.3 to 2809.1 N 2. half porcelain occlusal surfaced PFG Crown: 3689.4 to 3819.8 N 3. Ice Zirkon Crown: 1501.2 to 1867.9 N 4. Empress 2 Crown: 803.2 to 1188.5 N 5. boiled crab: 294.1 to 367.9 N 6. boiled chicken with bone: 357.1 to 408.6 N 7. boiled beef rib: 4077.7 to 4356.0 N 8. dried squid: 147.5 to 190.5 N 9. dried anchovy: 35.6 to 46.5 N 10. round candy: 1900.5 to 2615.8 N 11. walnut shell: 85.7 to 373.1 N under cyclic load(14Hz) in MTS, fracture load and masticatory cycles are: 1. full porcelain occlusal surfaced PFG Crown fractured at 95% confidence intervals of 4796.8-9321.2 cycles under 2224.8 N(round candy)load, no fracture under smaller loads. 2. half porcelain occlusal surfaced PFG Crown fractured at 95% confidence intervals of 881705.1-1143565.7 cycles under 2224.8 N(round candy). no fracture under smaller loads. 3. Ice Zirkon Crown fractured at 95% confidence intervlas of 979993.0-1145773.4 cycles under 382.9 N(boiled chicken with bone). no fracture under smaller loads. 4. Empress 2 Crown fractured at 95% confidence intervals of 564.1-954.7 cycles under 382.9 N(boiled chicken with bone). no fracture under smaller loads. Conclusion: There was a significant difference in fracture resistance between experimental groups. Under single load, Korean foods than can cause fracture to the dental ceramic restorations are boiled beef rib and round candy. Even if there is no fracture under single load, cyclic dynamic load can fracture dental posterior ceramic crowns. Experimental data with 14 Hz dynamic cyclic load are obtained as follows. 1. PFG crown(full porcelain occlusion) was failed after mean 0.03 years under fracture load for round candy(2224.8 N). 2. PFG crown(half porcelain occlusion) was failed after mean 4.1 years under fracture load for round candy(2224.8 N). 3. Ice Zirkon crown was failed after mean 4.3 years under fracture load for boiled chicken with bone(382.9 N). 4. Empress 2 crown was failed after mean 0.003 years under fracture load for boiled chicken with bone(382.9 N).

A Study on the Growth Diagnosis and Management Prescription for Population of Retusa Fringe Trees in Pyeongji-ri, Jinan(Natural Monument No. 214) (진안 평지리 이팝나무군(천연기념물 제214호)의 생육진단 및 관리방안)

  • Rho, Jae-Hyun;Oh, Hyun-Kyung;Han, Sang-Yub;Choi, Yung-Hyun;Son, Hee-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.36 no.3
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    • pp.115-127
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    • 2018
  • This study was attempted to find out the value of cultural assets through the clear diagnosis and prescription of the dead and weakness factors of the Population of Retusa Fringe Trees in Pyeongji-ri, Jinan(Natural Monument No. 214), The results are as follows. First, Since the designation of 13 natural monuments in 1968, since 1973, many years have passed since then. In particular, despite the removal of some of the buried soil during the maintenance process, such as retreating from the fence of the primary school after 2010, Second, The first and third surviving tree of the designated trees also have many branches that are dead, the leaves are dull, and the amount of leaves is small. vitality of tree is 'extremely bad', and the first branch has already been faded by a large number of branches, and the amount of leaves is considerably low this year, so that only two flowers are bloomed. The second is also in a 'bad'state, with small leaves, low leaf density, and deformed water. The largest number 1 in the world is added to the concern that the s coverd oil is assumed to be paddy soils. Third, It is found that the composition ratio of silt is high because it is known as '[silty loam(SiL)]'. In addition, the pH of the northern soil at pH 1 was 6.6, which was significantly different from that of the other soil. In addition, the organic matter content was higher than the appropriate range, which is considered to reflect the result of continuous application for protection management. Fourth, It is considered that the root cause of failure and growth of Jinan pyeongji-ri Population of Retusa Fringe Trees group is chronic syndrome of serious menstrual deterioration due to covered soil. This can also be attributed to the newly planted succession and to some of the deaths. Fifthly, It is urgent to gradually remove the subsoil part, which is estimated to be the cause of the initial damage. Above all, it is almost impossible to remove the coverd soil after grasping the details of the soil, such as clayey soil, which is buried in the rootstock. After removal of the coverd soil, a pestle is installed to improve the respiration of the roots and the ground with Masato. And the dead 4th dead wood and the 5th and 6th dead wood are the best, and the lower layer vegetation is mown. The viable neck should be removed from the upper surface, and the bark defect should undergo surgery and induce the development of blindness by vestibule below the growth point. Sixth, The underground roots should be identified to prepare a method to improve the decompression of the root and the respiration of the soil. It is induced by the shortening of rotten roots by tracing the first half of the rootstock to induce the generation of new roots. Seventh, We try mulching to suppress weed occurrence, trampling pressure, and soil moisturizing effect. In addition, consideration should be given to the fertilization of the foliar fertilizer, the injection of the nutrients, and the soil management of the inorganic fertilizer for the continuous nutrition supply. Future monitoring and forecasting plans should be developed to check for changes continuously.

Primary Orbital Lymphoma : A Retrospective Analysis of Results of Radiation Therapy (원발성 안와 림프종의 방사선치료 성적에 관한 후향적 분석)

  • Kim Sussan;Ahn Seung Do;Chang Hyesook;Kim Kyoung Ju;Lee Sang-wook;Choi Eun Kyung;Kim Jong Hoon;Huh Jooryung;Suh Cheol Won;Kim Sung Bae
    • Radiation Oncology Journal
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    • v.20 no.2
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    • pp.139-146
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    • 2002
  • Purpose : This study evaluated the treatment outcomes, patterns of failure, and treatment related complications of primary lymphoma patients who received definitive radiation therapy. Materials and Methods : A retrospective analysis was undertaken for 31 patients with primary orbital lymphoma at the Asan Medical Center between February 1991 and April 2001. There were 18 males and 13 females with ages ranging from 3 to 73 years (median, 44 years). The involved sites were 9 conjunctivae, 12 eyelids and 10 other orbits. The histological types were 28 MALT lymphomas (low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type), 1 diffuse large B-cell lymphoma, 1 anaplastic large cell lymphoma and 1 lymphoblastic lymphoma. The Ann Arbor stages were all IE $(100\%)$. Ann Arbor stage III or IV patients were excluded from this study, Bilateral orbital involvement occurred in 6 cases. Radiation therapy was given with one anterior port of high energy electrons $(6\~16\;MeV)$ for the lesions located at the anterior structures like the conjunctivae or eyelids. Lesions with a posterior extension or other orbital lesions were treated with 4 or 6 MeV photons with appropriately arranged portals. In particular, lens blocks composed of lead alloy were used in conjunctival or eyelid lesions. Twelve patients received chemotherapy. The median follow-up period was 53 months. Results : The 5-year overall, cause-specific, and disease-free survival was $91\%,\;96\%,\;and\;80\%$, respectively. The complete response rate 6 months after radiation therapy was $100\%$. Local recurrences were observed in 2 patients at 16 and 18 months after completion of radiation treatment. They were salvaged with additional radiation therapy. Two patients developed distant metastases. A MALT lymphoma patient with a lung relapse was successfully salvaged with radiotherapy, but the other lymphoblastic lymphoma patient with bone marrow relapse expired. There were no severe complications but 5 patients developed radiation-induced cataracts and 2 patients developed dry eye. Conclusion : Most primary orbital lymphomas consisted of MALT lymphomas. Radiation therapy was a successful treatment modality for orbital lymphoma without any severe complications. In cases of local relapses, radiation therapy is also a very successful salvage treatment modality.

A Study of Anomaly Detection for ICT Infrastructure using Conditional Multimodal Autoencoder (ICT 인프라 이상탐지를 위한 조건부 멀티모달 오토인코더에 관한 연구)

  • Shin, Byungjin;Lee, Jonghoon;Han, Sangjin;Park, Choong-Shik
    • Journal of Intelligence and Information Systems
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    • v.27 no.3
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    • pp.57-73
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    • 2021
  • Maintenance and prevention of failure through anomaly detection of ICT infrastructure is becoming important. System monitoring data is multidimensional time series data. When we deal with multidimensional time series data, we have difficulty in considering both characteristics of multidimensional data and characteristics of time series data. When dealing with multidimensional data, correlation between variables should be considered. Existing methods such as probability and linear base, distance base, etc. are degraded due to limitations called the curse of dimensions. In addition, time series data is preprocessed by applying sliding window technique and time series decomposition for self-correlation analysis. These techniques are the cause of increasing the dimension of data, so it is necessary to supplement them. The anomaly detection field is an old research field, and statistical methods and regression analysis were used in the early days. Currently, there are active studies to apply machine learning and artificial neural network technology to this field. Statistically based methods are difficult to apply when data is non-homogeneous, and do not detect local outliers well. The regression analysis method compares the predictive value and the actual value after learning the regression formula based on the parametric statistics and it detects abnormality. Anomaly detection using regression analysis has the disadvantage that the performance is lowered when the model is not solid and the noise or outliers of the data are included. There is a restriction that learning data with noise or outliers should be used. The autoencoder using artificial neural networks is learned to output as similar as possible to input data. It has many advantages compared to existing probability and linear model, cluster analysis, and map learning. It can be applied to data that does not satisfy probability distribution or linear assumption. In addition, it is possible to learn non-mapping without label data for teaching. However, there is a limitation of local outlier identification of multidimensional data in anomaly detection, and there is a problem that the dimension of data is greatly increased due to the characteristics of time series data. In this study, we propose a CMAE (Conditional Multimodal Autoencoder) that enhances the performance of anomaly detection by considering local outliers and time series characteristics. First, we applied Multimodal Autoencoder (MAE) to improve the limitations of local outlier identification of multidimensional data. Multimodals are commonly used to learn different types of inputs, such as voice and image. The different modal shares the bottleneck effect of Autoencoder and it learns correlation. In addition, CAE (Conditional Autoencoder) was used to learn the characteristics of time series data effectively without increasing the dimension of data. In general, conditional input mainly uses category variables, but in this study, time was used as a condition to learn periodicity. The CMAE model proposed in this paper was verified by comparing with the Unimodal Autoencoder (UAE) and Multi-modal Autoencoder (MAE). The restoration performance of Autoencoder for 41 variables was confirmed in the proposed model and the comparison model. The restoration performance is different by variables, and the restoration is normally well operated because the loss value is small for Memory, Disk, and Network modals in all three Autoencoder models. The process modal did not show a significant difference in all three models, and the CPU modal showed excellent performance in CMAE. ROC curve was prepared for the evaluation of anomaly detection performance in the proposed model and the comparison model, and AUC, accuracy, precision, recall, and F1-score were compared. In all indicators, the performance was shown in the order of CMAE, MAE, and AE. Especially, the reproduction rate was 0.9828 for CMAE, which can be confirmed to detect almost most of the abnormalities. The accuracy of the model was also improved and 87.12%, and the F1-score was 0.8883, which is considered to be suitable for anomaly detection. In practical aspect, the proposed model has an additional advantage in addition to performance improvement. The use of techniques such as time series decomposition and sliding windows has the disadvantage of managing unnecessary procedures; and their dimensional increase can cause a decrease in the computational speed in inference.The proposed model has characteristics that are easy to apply to practical tasks such as inference speed and model management.

Clinical Study of Corrosive Injury of the Esophagus (식도부식증의 임상적 고찰)

  • 박철원;송기준;이형석;안경성;김선곤
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1981.05a
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    • pp.5.3-6
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    • 1981
  • There are too many kinds of esophageal corrosive agents, such as sodium hydrochloride, acetic acid, hydrochloric acid, etc. Esophageal burn due to above chemical agents are decreasing recently, but still many patients visited to the hospital because of swallowing corrosive agents for the purpose of suicide or accidentally. Among the treatment of corrosive injury of the esophagus, prevention of esophageal stricture is the key point. Recently various methods are using as the treatment of corrosive esophagitis and prevention of esophageal stricture. 51 cases of corrosive injury of the esophagus who had been admitted and treated at the Dept. of Otolaryngology, Han Yang University Hospital during past 9 years (from May 1972 to Dec. 1980) were evaluated and report the result about age distribution, sex incidence, monthly distribution, cause of swallowing, swallowing agents, arriving time at hospital after swallowing, changes on oral and pharyngeal mucosa, laboratory findings, emergency treatment and treatment during admission, treatment follow up results and complications with review of liter ature. Following results were obtained; 1. Female patients 27 cases (52.9%) were more than male patients 24 cases (47.1%) and its ratio was 1.13 : 1. 2. Age distribution showed predilection for age of 21-30 with 20 cases(39.2%), and 11-20 with 11 cases (21.6%), 31-40 with 7 cases(13.7%), over 50 with 7 cases (13.7%) were following. 3. Monthly distribution showed predilection for March with 8 cases(15.7%), and April, July with 7 cases (13.7%), September with 6 cases(l1.8%), October 5 cases(9.8%) were following. 4. For the purpose of suicide was the most cause of swallowing with 40 cases(78.4%), and accidentally swallowing 11 cases(21.6%). 5. Acetic acid was the most swallowing agent with 24 cases (47.0%), and hydrochloric acid 11 cases (21.5%), lye 8 cases(15.7%), iodine 2 cases(3.9%) were following. 6. Arriving time at the hospital after swallowing showed predilection for within 12 hours with 42 cases (82.4%), and from 12 hours to 24 hours with 4 cases(7.8%) was next. 7. Moderate change with injection and swelling was the prevalent change on oral and pharyngeal mucosa with 20 cases(39.2%) and severe cases with ulceration 18 cases (35.3%), mild cases with injection 10 cases (19.6%) were following. 8. Leukocytosis was seen on 40 cases (78.4%), and increased Hct. was seen 31 cases (60.8%). On urine analysis, 14 cases(27.5%) showed over 1.030 S.G., and proteinuria was seen on 25 cases(49.0%), glycosuria was seen on 5 cases(9.8%) and hematuria was seen on 6 cases(11.8). 9. Gastric lavage was done on 30 cases (58.8%) as emergency treatment and on 3 cases(5.9%) tracheostomy was done for the airway keeping. 10. As methods of treatment during admission, L-tube insertion was done on 50 cases (98.0%), antibiotics was given to 49 cases (96.1%), steroid and antacid were given to 46 cases(90.2%). 11. 36 cases(70.6%) were in favorable condition after proper treatment, but 2 cases (3.9%) were expired during admission, 4 cases (7.8%) showed esophageal stricture in-spite of treatment, and 1 case(2.0%) showed pyloric stenosis. 12. Complications were observed in 8 cases (17.7%). Renal failure (4 cases), aspiration pneumonia (2 cases), upper G-I bleeding (1 cases), and diabetic coma (1 cases) were seen in order of frequency.

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Hemophagocytic Syndrome Presenting as Severe Acute Hepatitis (중증 급성 간염으로 발현한 혈구탐식증후군에 관한 연구)

  • Ryu, Jeong Min;Chang, Soo Hee;Kim, Joon Sung;Lee, Joo Hoon;Lee, Mi Jeong;Park, Kie Young;Kim, Kyung Mo;Seo, Jong Jin;Moon, Hyung Nam;Ghim, Thad;Chi, Hyun Sook
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.8 no.2
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    • pp.213-221
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    • 2005
  • Purpose: Hemophagocytic syndrome (HPS) is characterized by persistent high fever, hepatosplenomegaly, cytopenias, hypertriglyceridemia, and/or hypofibrinogenemia. Hepatic manifestations including overt hepatic failure and fulminant hepatitis are common in HPS. Liver transplantation (LT) should be considered in a case of fulminant hepatitis by other than HPS, but LT is contraindicated and complete cure is possible by chemotherapy in HPS. Therefore, we conducted this study to define the characteristics of HPS presenting as severe acute hepatitis. Methods: Among the total of 23 patients diagnosed as HPS by bone marrow examination between 1994 and 2005 in Asan Medical Center, 11 cases presented as severe acute hepatitis were enrolled in this study. We analyzed the clinical features, laboratory findings and outcome retrospectively. Results: Seven (64%) of the 11 children with HPS and hepatitis were referred to pediatric gastroenterologist at first. The mean age of onset was 50 months. There was no case with family history of primary HPS. Epstein-Barr virus was positive in 4, and herpes Simplex virus was positive simultaneously in 1 case. As the presenting symptoms and signs, fever was present in 10, hepatosplenomagaly was noted in all and jaundice in 10. Anemia was observed in 10, thrombocytopenia in 10, leukopenia in 8, hypertriglyceridemia in 9, hypofibrinogenemia in 8 and hyperferritinemia in 7 cases, respectively. Nine children received chemotherapy including etopside. The overall mortality rate was 72% (8/11). Conclusion: HPS, which needs chemotherapy, should be considered as a cause of severe acute hepatitis especially when accompanied with prolonged high fever and cytopenias.

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A Study on Actual Usage of Information Systems: Focusing on System Quality of Mobile Service (정보시스템의 실제 이용에 대한 연구: 모바일 서비스 시스템 품질을 중심으로)

  • Cho, Woo-Chul;Kim, Kimin;Yang, Sung-Byung
    • Asia pacific journal of information systems
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    • v.24 no.4
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    • pp.611-635
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    • 2014
  • Information systems (IS) have become ubiquitous and changed every aspect of how people live their lives. While some IS have been successfully adopted and widely used, others have failed to be adopted and crowded out in spite of remarkable progress in technologies. Both the technology acceptance model (TAM) and the IS Success Model (ISSM), among many others, have contributed to explain the reasons of success as well as failure in IS adoption and usage. While the TAM suggests that intention to use and perceived usefulness lead to actual IS usage, the ISSM indicates that information quality, system quality, and service quality affect IS usage and user satisfaction. Upon literature review, however, we found a significant void in theoretical development and its applications that employ either of the two models, and we raise research questions. First of all, in spite of the causal relationship between intention to use and actual usage, in most previous studies, only intention to use was employed as a dependent variable without overt explaining its relationship with actual usage. Moreover, even in a few studies that employed actual IS usage as a dependent variable, the degree of actual usage was measured based on users' perceptual responses to survey questionnaires. However, the measurement of actual usage based on survey responses might not be 'actual' usage in a strict sense that responders' perception may be distorted due to their selective perceptions or stereotypes. By the same token, the degree of system quality that IS users perceive might not be 'real' quality as well. This study seeks to fill this void by measuring the variables of actual usage and system quality using 'fact' data such as system logs and specifications of users' information and communications technology (ICT) devices. More specifically, we propose an integrated research model that bring together the TAM and the ISSM. The integrated model is composed of both the variables that are to be measured using fact as well as survey data. By employing the integrated model, we expect to reveal the difference between real and perceived degree of system quality, and to investigate the relationship between the perception-based measure of intention to use and the fact-based measure of actual usage. Furthermore, we also aim to add empirical findings on the general research question: what factors influence actual IS usage and how? In order to address the research question and to examine the research model, we selected a mobile campus application (MCA). We collected both fact data and survey data. For fact data, we retrieved them from the system logs such information as menu usage counts, user's device performance, display size, and operating system revision version number. At the same time, we conducted a survey among university students who use an MCA, and collected 180 valid responses. A partial least square (PLS) method was employed to validate our research model. Among nine hypotheses developed, we found five were supported while four were not. In detail, the relationships between (1) perceived system quality and perceived usefulness, (2) perceived system quality and perceived intention to use, (3) perceived usefulness and perceived intention to use, (4) quality of device platform and actual IS usage, and (5) perceived intention to use and actual IS usage were found to be significant. In comparison, the relationships between (1) quality of device platform and perceived system quality, (2) quality of device platform and perceived usefulness, (3) quality of device platform and perceived intention to use, and (4) perceived system quality and actual IS usage were not significant. The results of the study reveal notable differences from those of previous studies. First, although perceived intention to use shows a positive effect on actual IS usage, its explanatory power is very weak ($R^2$=0.064). Second, fact-based system quality (quality of user's device platform) shows a direct impact on actual IS usage without the mediating role of intention to use. Lastly, the relationships between perceived system quality (perception-based system quality) and other constructs show completely different results from those between quality of device platform (fact-based system quality) and other constructs. In the post-hoc analysis, IS users' past behavior was additionally included in the research model to further investigate the cause of such a low explanatory power of actual IS usage. The results show that past IS usage has a strong positive effect on current IS usage while intention to use does not have, implying that IS usage has already become a habitual behavior. This study provides the following several implications. First, we verify that fact-based data (i.e., system logs of real usage records) are more likely to reflect IS users' actual usage than perception-based data. In addition, by identifying the direct impact of quality of device platform on actual IS usage (without any mediating roles of attitude or intention), this study triggers further research on other potential factors that may directly influence actual IS usage. Furthermore, the results of the study provide practical strategic implications that organizations equipped with high-quality systems may directly expect high level of system usage.

The Effectiveness of Spiral Computed Tomography as a Diagnostic Tool in Pulmonary Embolism(Comparison of Spiral CT with Ventilation-Perfusion Scan) (폐색전증 진단의 도구로서의 Spiral Computed Tomography의 유용성(폐환기관류주사와의 비교))

  • Koh, Jae-Hyun;Oh, Eun-Young;Park, Jung-Ho;Park, Sang-Joon;Yun, Jung-Hwan;Park, Jung-Woong;Suh, Gee-Young;Chung, Man-Pyo;Lee, Kyung-Soo;Kwon, O-Jung;Rhee, Chong-H.
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.4
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    • pp.564-573
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    • 1999
  • Background: With variable symptoms and nonspecific radiographic appearances, pulmonary embolism (PE) is a frequent and often undiagnosed cause of mortality and morbidity. The Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study suggested that the majority of patients undergoing ventilation-perfusion (V-Q) scan would require additional studies to establish or to exclude the diagnosis of PE. Pulmonary angiography has been regarded as gold standard for diagnosis of PE. However, it is an invasive procedure that may be associated with significant notable morbidity and mortality. Thus, availability of an accurate, noninvasive screening examination is highly desirable. Method: From October 1994 to February 1997, twenty patients (male 13, female 7, range 23-91 years, median 58 years) who were suspected as pulmonary embolism on the basis of clinical evidence and underwent the spiral volumetric computed tomography (spiral CT), were studied retrospectively to evaluate the effectiveness of spiral CT as a diagnostic tool in PE. Results: PE could be excluded with spiral CT in 4 patients ; diagnoses of these patients were lung cancer, pneumonia with lung abscess, bilateral pleural effusion due to congestive heart failure, nonspecific pulmonary abnormality retrospectively. One patient who disclosed high probability in V/Q scan, could be diagnosed as pneumonia with lung abscess and underlying emphysema with spiral CT. Among 4 patients who showed intermediate and low probability in V/Q scan, 3 patients could be confirmed as PE with spiral CT. Spiral CT was helpful in 3 patients, in whom V/Q scan could not be performed due to other reasons (e.g. night time, mechanical ventilation) to confirm the diagnosis of PE. Spiral CT could demonstrate embolus above lobar artery level in 11 patients, and up to segmental artery level in 5 patients. Conclusion: This study demonstrated that spiral CT could allow accurate demonstration of thrombotic clots in centrally localized embolism. Spiral CT could be effective, specific, noninvasive and useful diagnostic screening modality for the diagnosis of pulmonary embolism.

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Treatment Outcomes and Prognostic Factors in Patients with Multidrug-Resistant Tuberculosis in Korean Private Hospitals (국내 민간병원에서 치료한 다제내성결핵 환자의 치료 결과 및 예후 인자)

  • Park, Jin-Kyeong;Koh, Won-Jung;Kim, Deog-Kyeom;Kim, Eun-Kyung;Kim, Yu-Il;Kim, Hee-Jin;Kim, Tae-Hyung;Kim, Jae-Yeol;Park, Moo-Suk;Park, I-Nae;Park, Jae-Seuk;Lee, Ki-Man;Song, Sook-Hee;Lee, Jin-Hwa;Lee, Seung-Heon;Lee, Hyuk-Pyo;Yim, Jae-Joon;Lim, Jae-Min;JeGal, Yang-Jin;Jung, Ki-Hwan;Huh, Jin-Won;Choi, Jae-Chol;Shim, Tae-Sun
    • Tuberculosis and Respiratory Diseases
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    • v.69 no.2
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    • pp.95-102
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    • 2010
  • Background: The increasing rate of drug-resistant tuberculosis (TB) is a threat to the public health and TB control. In Korea, about 75~80% of TB patients are treated in private hospitals and the rate has been continuously increasing since 2000. Methods: On a retrospective basis, we enrolled 170 newly diagnosed with or retreated for multidrug-resistant TB (MDR-TB) in 2004 from 21 private hospitals. We extracted the following demographics and treatment history from patient medical records: initial treatment outcomes, cumulative survival rates, treatment outcomes, and prognostic factors. Results: Of the 170 patients, the majority were male (64.1%), the mean age was 44.5 years old, and mean body-mass-index was $20.2kg/m^2$. None of the patients tested positive for HIV. Eleven (6.5%) were confirmed to have extensively drug-resistant TB (XDR-TB) at treatment initiation. Treatment success rates were not different between XDR-TB (36.4%, 4/11) and non-XDR MDR-TB (51.6%, 82/159). Default rate was high, 21.8% (37/170). Far advanced disease on X-ray was a significant negative predictor of treatment success; advanced disease and low BMI were risk factors for all-cause mortality. Conclusion: In private hospitals in Korea, the proportion of XDR-TB in MDR-TB was comparable to previous data. The treatment success rate of MDR-/XDR-TB remains poor and the failure rate was quite high. Adequate TB control policies should be strengthened to prevent the further development and spread of MDR-/XDR-TB in Korea.