• Journal of Korean Society of Disaster and Security
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• v.14 no.4
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• pp.17-27
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• 2021

Streamflow prediction is a very vital disaster mitigation approach for effective flood management and water resources planning. Lately, torrential rainfall caused by climate change has been reported to have increased globally, thereby causing enormous infrastructural loss, properties and lives. This study evaluates the contribution of rainfall to streamflow prediction in normal and peak rainfall scenarios, typical of the recent flood at Piney Resort in Vernon, Hickman County, Tennessee, United States. Daily streamflow, water level, and rainfall data for 20 years (2000-2019) from two USGS gage stations (03602500 upstream and 03599500 downstream) of the Piney River watershed were obtained, preprocesssed and fitted with Long short term memory (LSTM) model. Tensorflow and Keras machine learning frameworks were used with Python to predict streamflow values with a sequence size of 14 days, to determine whether the model could have predicted the flooding event in August 21, 2021. Model skill analysis showed that LSTM model with full data (water level, streamflow and rainfall) performed better than the Naive Model except some rainfall models, indicating that only rainfall is insufficient for streamflow prediction. The final LSTM model recorded optimal NSE and RMSE values of 0.68 and 13.84 m³/s and predicted peak flow with the lowest prediction error of 11.6%, indicating that the final model could have predicted the flood on August 24, 2021 given a peak rainfall scenario. Adequate knowledge of rainfall patterns will guide hydrologists and disaster prevention managers in designing efficient early warning systems and policies aimed at mitigating flood risks.

• Journal of Internet Computing and Services
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• v.24 no.4
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• pp.127-135
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• 2023

This research paper explores the application of FinBERT, a variational BERT-based model pre-trained on financial domain, for sentiment analysis in the financial domain while focusing on the process of identifying suitable training data and hyperparameters. Our goal is to offer a comprehensive guide on effectively utilizing the FinBERT model for accurate sentiment analysis by employing various datasets and fine-tuning hyperparameters. We outline the architecture and workflow of the proposed approach for fine-tuning the FinBERT model in this study, emphasizing the performance of various datasets and hyperparameters for sentiment analysis tasks. Additionally, we verify the reliability of GPT-3 as a suitable annotator by using it for sentiment labeling tasks. Our results show that the fine-tuned FinBERT model excels across a range of datasets and that the optimal combination is a learning rate of 5e-5 and a batch size of 64, which perform consistently well across all datasets. Furthermore, based on the significant performance improvement of the FinBERT model with our Twitter data in general domain compared to our news data in general domain, we also express uncertainty about the model being further pre-trained only on financial news data. We simplify the complex process of determining the optimal approach to the FinBERT model and provide guidelines for selecting additional training datasets and hyperparameters within the fine-tuning process of financial sentiment analysis models.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.5
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• pp.199-206
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• 2023

The current software becomes the huge size of source codes. Therefore it is increasing the importance and necessity of static analysis for high-quality product. With static analysis of the code, it needs to identify the defect and complexity of the code. Through visualizing these problems, we make it guild for developers and stakeholders to understand these problems in the source codes. Our previous visualization research focused only on the process of storing information of the results of static analysis into the Database tables, querying the calculations for quality indicators (CK Metrics, Coupling, Number of function calls, Bad-smell), and then finally visualizing the extracted information. This approach has some limitations in that it takes a lot of time and space to analyze a code using information extracted from it through static analysis. That is since the tables are not normalized, it may occur to spend space and time when the tables(classes, functions, attributes, Etc.) are joined to extract information inside the code. To solve these problems, we propose a regularized design of the database tables, an extraction mechanism for quality metric indicators inside the code, and then a visualization with the extracted quality indicators on the code. Through this mechanism, we expect that the code visualization process will be optimized and that developers will be able to guide the modules that need refactoring. In the future, we will conduct learning of some parts of this process.

• Journal of the Korea Computer Graphics Society
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• v.29 no.5
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• pp.21-30
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• 2023

Accurate segmentation of the kidney tumor is necessary to identify shape, location and safety margin of tumor in abdominal CT images for surgical planning before renal partial nephrectomy. However, kidney tumor segmentation is challenging task due to the various sizes and locations of the tumor for each patient and signal intensity similarity to surrounding organs such as intestine and spleen. In this paper, we propose a semi-supervised learning-based mean teacher network that utilizes both labeled and unlabeled data using a kidney local guided map including kidney local information to segment small-sized kidney tumors occurring at various locations in the kidney, and analyze the performance according to the kidney tumor size. As a result of the study, the proposed method showed an F1-score of 75.24% by considering local information of the kidney using a kidney local guide map to locate the tumor existing around the kidney. In particular, under-segmentation of small-sized tumors which are difficult to segment was improved, and showed a 13.9%p higher F1-score even though it used a smaller amount of labeled data than nnU-Net.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.1
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• pp.3293-3301
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• 1974

An experimental work was conducted by using a laboratory-made model dryer to investigate the effect of the rate of natural forced-air on the drying rate of rough rice which was deposited in the deep-bed. The dryer consisted of 8 cylinderical containers with grain holding screen at their bottoms, each of which having 30cm in diameter and 15cm in height. The containers were sacked vertically with keeping them air-tight by using paper tape during dryer operation. Two separate layers of containers were operated in the same time to have two replications. The moisture contents of grains within each bins after predetermined period of dryer operation were determined indirectly by measuring the weight of the individual containers. The air-rates were maintained at 6 levels, or 5, 8, 10, 15, 18 and 20 millimenters of static head of water. The roomair conditions during dryer operation were maintained in the range of 10-l5$^{\circ}C$ in temperature and 40-60% in relative humidity. The results of the study are summarized as follows: 1. Drying characteristics of the grains in the bottom layers were approximately the same regardless of airdelivery rates, giving the average drying rate as about 0.35 percent per hour after 40-hour drying period, during which moisture content (w. b.) reduced from 24 percent to about 10 percent. 2. After about 40-hour drying period, the mean drying rates increased from 0.163 percent per hour to 0.263 percent per hour as air-flow rates increased from 5mm to 87.16mm of static head of water. In the same time, the moisture differences of grains between lower and upper layers varied from 12.7 percent at the air rate of 5mm of water head to 7.5 percent at the air-flow rate of 20mn of water head. Thus, the greater the air-flow rate was, the more overall improvement in drying performance was. Additionally, from the result of ineffectiveness of drying grain positioned at 70cm depth or above by the air rate of 5mm of static head of water it may be suggested in practical application that the height of grain deposit would be maintained adequately within the limits of air-rates that may be actually delivered. 3. Drying after layer-turning operation was continued for about 30 hours to test the effectiveness of reducing moisture differences in the thick layers. As a result of this layer-turning operation, moisture distribution through layers approached to narrow ranges, giving the moisture range as about 7 percent at air-flow rate of 5mm head of water, about 3 percent at 10mm head about 2 percent at 15mm head, and less than 1 percent at 20mm head. In addition, from the desirable results that drying rate was rapid in the lower layers and dully in the upper layers, layer-turning operation may be very effective in natural air drying with deep-layer grain deposit, especially when the forced air was kept in low rate. 4. Even though the high rate of air delivery is very desirable for deep-layer natural-air drying of rough rice, it can be happened that the required air delivery rate could not be attained because of limitation of power source available on farms. To give a guide line for the practical application, the power required to perform the drying with the specified air rate was analyzed for different sizes of drying bin and is given in Table (5). If a farmer selects a motor of which size is 1 or {{{{1 { 1} over {2 } }}}} H.P. and air-delivery rate which ranges from 8~10mm of head, the diameter of grain bin may be suggested to choose about 2.4m, also power tiller or other moderate size of prime motor may be recommended when the diameter of grain bin is about 5.0m or more for about 120cm grain deposit.

• Tuberculosis and Respiratory Diseases
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• v.56 no.5
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• pp.485-494
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• 2004

Background : To assess the effects of mDOT implementation on sputum smear conversion for AFB (Acid fast bacilli) positive pulmonary tuberculosis patients, modified Directly Observed Treatment (mDOT) was started on October $8^{th}$ 2001 at a health center in Seoul. mDOT was defined through weekly interviewing and supervising of a patient by a supervisor (doctor, nurse, or lay health worker). The sputum smear conversion of a mDOT group was compared with that of a self-medication (self) group. Methods : This study included 52 AFB positive pulmonary tuberculosis patients registered at a health center in Seoul between October $8^{th}$ 2001 and April $23^{rd}$ 2002. 24 and 28 patients were enrolled in the mDOT and self medication groups, respectively. Paired (1:1) individual matching, by gender, extent of disease, relapse and age-matching variables, was performed between the two groups, resulting in 20 paired matches. This prospective study was planned as an unblinded, non-randomized quasiexperimental pilot project. Outcomes were identified from results of sputum smear examinations for AFB in both groups at 2 weeks, and 1 and 2 months. The paired matching data were analyzed using the SAS program version 8.1 by McNemar test. Results : At the end of 2 weeks of treatment, the sputum smear conversion of the mDOT group was somewhat higher than that of the self medication group (78.57 vs. 50%, p-value=0.289), and after 1 month of treatment no statistically significant difference was shown between the two groups (83.33 vs. 50, p-value=0.125). At the end of 2 months of treatment (initial intensive phase), the sputum smear conversions of the mDOT and self groups were 95 and 75%, respectively (p-value=0.219). Conclusions : The implementation of mDOT did not result in clinically significant increases in the sputum smear conversion at 2 weeks, and 1 and 2 months compared with that of the self medication group. However, the increases experienced might contribute to diminishing the infectious period of AFB positive patients, and this approach may act as a guide for a specific group of patients. In this study, mDOT was performed for one hundred percent of the intensive treatment phase. It can also be an effective treatment for pulmonary tuberculosis patients, and may be useful for some high risk tuberculosis patients.

• Journal of Korean Home Economics Education Association
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• v.17 no.2
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• pp.29-47
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• 2005

In this study. we tried to provide basic materials for teachers to develop consumer's guide of internet shopping for middle and high school students through surveying their Purchase realities, clothing purchase behaviors. and clothing purchase attitudes when they use internet shopping mall. The questionaires were distributed to middle and high school students in Seoul, Daegu, Kyunggi, Chungbuk, Chungnam, Kyungbuk, and Kyungnam November, 2004. The followings are the results of this study. First, clothing items which were bought in internet shopping malls were shirts. shoes, pants, bags in order and they were below $20,000\~30,000$ won. Main payment method used was sending money to seller's account. Second, clothing purchase satisfaction degree was comparatively high but the satisfaction degree for the compensation policy was low. If they had any claims for the products. they were likely to behave more actively than passively. Third. returned items were shirts, pants, shoes in order which are the same as purchasing items and they were due to the size and the difference between the products recognised by computer screen and the real products. The $89.0\%$ of the subjects who have purchased clothing through internet expressed high intention to purchase in the future through internet. Forth the degree of attitude toward the internet shopping concerned with clothing purchase was high in the factor of 'convenience of shopping', especially they thought that the purchase through internet had the advantage of varieties and prices. The significant differences were found (1) in the experience of purchase and clothing purchase through internet according to their regions. school years, allowances per month, (2) in the purchased items through internet according to only their sexes, and (3) in the desired Purchase items through internet according to school years, their sexes. regions. The more frequently the middle and high school students use internet, the more goods they purchase through internet, especially the portion of the purchased clothing is getting bigger year by year. This suggests that we need to develope well-organized programs to teach good consumer's attitude to the middle and high school students when they purchase through internet.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.498-506
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• 1999

Background : The causes of solitary pulmonary nodule are many, but the main concern is whether the nodule is benign or malignant. Because a solitary pulmonary nodule is the initial manifestation of the majority of lung cancer, accurate clinical and radiologic interpretation is important. Bayes' theorem is a simple method of combining clinical and radiologic findings to estimate the probability that a nodule in an individual patients is malignant. We estimated the probability of malignancy of solitary pulmonary nodules with a specific combination of features by Bayesian approach. Method : One hundred and eighty patients with solitary pulmonary nodules were identified from multi-center analysis. The hospital records of these patients were reviewed and patient age, smoking history, original radiologic findings, and diagnosis of the solitary pulmonary nodules were recorded. The diagnosis of solitary pulmonary nodule was established pathologically in all patients. We used to Bayes' theorem to devise a simple scheme for estimating the likelihood that a solitary pulmonary nodule is malignant based on radiological and clinical characteristics. Results : In patients characteristics, the probability of malignancy increases with advancing age, peaking in patients older than 66 year of age(LR : 3.64), and higher in patients with smoking history more than 46 pack years(LR : 8.38). In radiological features, the likelihood ratios were increased with increasing size of the nodule and nodule with lobulated or spiculated margin. Conclusion : In conclusion, the likelihood ratios of malignancy may improve the accuracy of the probability of malignancy, and can be a guide of management of solitary pulmonary nodule.

• Journal of Intelligence and Information Systems
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• v.21 no.3
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• pp.117-129
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• 2015

As the Internet becomes ubiquitous, a large volume of information is posted on the Internet with exponential growth every day. Accordingly, it is not unusual that investors in stock markets gather and compile firm-specific or market-wide information through online searches. Importantly, it becomes easier for investors to acquire value-relevant information for their investment decision with the help of powerful search tools on the Internet. Our study examines whether or not the Internet helps investors assess a firm's value better by using firm-level data over long periods spanning from January 2004 to December 2013. To this end, we construct weekly-based search volume for information technology (IT) services firms on the Internet. We limit our focus to IT firms since they are often equipped with intangible assets and relatively less recognized to the public which makes them hard-to measure. To obtain the information on those firms, investors are more likely to consult the Internet and use the information to appreciate the firms more accurately and eventually improve their investment decisions. Prior studies have shown that changes in search volumes can reflect the various aspects of the complex human behaviors and forecast near-term values of economic indicators, including automobile sales, unemployment claims, and etc. Moreover, search volume of firm names or stock ticker symbols has been used as a direct proxy of individual investors' attention in financial markets since, different from indirect measures such as turnover and extreme returns, they can reveal and quantify the interest of investors in an objective way. Following this line of research, this study aims to gauge whether the information retrieved from the Internet is value relevant in assessing a firm. We also use search volume for analysis but, distinguished from prior studies, explore its impact on return comovements with market returns. Given that a firm's returns tend to comove with market returns excessively when investors are less informed about the firm, we empirically test the value of information by examining the association between Internet searches and the extent to which a firm's returns comove. Our results show that Internet searches are negatively associated with return comovements as expected. When sample is split by the size of firms, the impact of Internet searches on return comovements is shown to be greater for large firms than small ones. Interestingly, we find a greater impact of Internet searches on return comovements for years from 2009 to 2013 than earlier years possibly due to more aggressive and informative exploit of Internet searches in obtaining financial information. We also complement our analyses by examining the association between return volatility and Internet search volumes. If Internet searches capture investors' attention associated with a change in firm-specific fundamentals such as new product releases, stock splits and so on, a firm's return volatility is likely to increase while search results can provide value-relevant information to investors. Our results suggest that in general, an increase in the volume of Internet searches is not positively associated with return volatility. However, we find a positive association between Internet searches and return volatility when the sample is limited to larger firms. A stronger result from larger firms implies that investors still pay less attention to the information obtained from Internet searches for small firms while the information is value relevant in assessing stock values. However, we do find any systematic differences in the magnitude of Internet searches impact on return volatility by time periods. Taken together, our results shed new light on the value of information searched from the Internet in assessing stock values. Given the informational role of the Internet in stock markets, we believe the results would guide investors to exploit Internet search tools to be better informed, as a result improving their investment decisions.

• Asia pacific journal of information systems
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• v.23 no.2
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• pp.21-39
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• 2013

As the utilization of information technology and the turbulence of technological change increase in organizations, the adoption of IT outsourcing also grows to manage IT resource more effectively and efficiently. In this new way of IT management technique, service level management(SLM) process becomes critical to derive success from the outsourcing in the view of end users in organization. Even though much of the research on service level management or agreement have been done during last decades, the performance of the service level management process have not been evaluated in terms of final objectives of the management efforts or success from the view of end-users. This study explores the relationship between SLM maturity and IT outsourcing success from the users' point of view by a analytical case study in four client organizations under an IT outsourcing vendor, which is a member company of a major Korean conglomerate. For setting up a model for the analysis, previous researches on service level management process maturity and information systems success are reviewed. In particular, information systems success from users' point of view are reviewed based the DeLone and McLean's study, which is argued and accepted as a comprehensively tested model of information systems success currently. The model proposed in this study argues that SLM process maturity influences information systems success, which is evaluated in terms of information quality, systems quality, service quality, and net effect proposed by DeLone and McLean. SLM process maturity can be measured in planning process, implementation process and operation and evaluation process. Instruments for measuring the factors in the proposed constructs of information systems success and SL management process maturity were collected from previous researches and evaluated for securing reliability and validity, utilizing appropriate statistical methods and pilot tests before exploring the case study. Four cases from four different companies under one vendor company were utilized for the analysis. All of the cases had been contracted in SLA(Service Level Agreement) and had implemented ITIL(IT Infrastructure Library), Six Sigma and BSC(Balanced Scored Card) methods since last several years, which means that all the client organizations pursued concerted efforts to acquire quality services from IT outsourcing from the organization and users' point of view. For comparing the differences among the four organizations in IT out-sourcing sucess, T-test and non-parametric analysis have been applied on the data set collected from the organization using survey instruments. The process maturities of planning and implementation phases of SLM are found not to influence on any dimensions of information systems success from users' point of view. It was found that the SLM maturity in the phase of operations and evaluation could influence systems quality only from users' view. This result seems to be quite against the arguments in IT outsourcing practices in the fields, which emphasize usually the importance of planning and implementation processes upfront in IT outsourcing projects. According to after-the-fact observation by an expert in an organization participating in the study, their needs and motivations for outsourcing contracts had been quite familiar already to the vendors as long-term partners under a same conglomerate, so that the maturity in the phases of planning and implementation seems not to be differentiating factors for the success of IT outsourcing. This study will be the foundation for the future research in the area of IT outsourcing management and success, in particular in the service level management. And also, it could guide managers in practice in IT outsourcing management to focus on service level management process in operation and evaluation stage especially for long-term outsourcing contracts under very unique context like Korean IT outsourcing projects. This study has some limitations in generalization because the sample size is small and the context itself is confined in an unique environment. For future exploration, survey based research could be designed and implemented.