• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.1
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• pp.6-19
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• 2023

A systematic review was conducted in compliance with PRISMA statement standards to identify all studies reporting outcomes of laparoscopic resection of benign or malignant lesions located in caudate lobe of liver. Pooled outcome data were calculated using random-effects models. A total of 196 patients from 12 studies were included. Mean operative time, volume of intraoperative blood loss, and length of hospital stay were 225 minutes (95% confidence interval [CI], 181-269 minutes), 134 mL (95% CI, 85-184 mL), and 7 days (95% CI, 5-9 days), respectively. The pooled risk of need for intraoperative transfusion was 2% (95% CI, 0%-5%). It was 3% (95% CI, 1%-6%) for conversion to open surgery, 6% (95% CI, 0%-19%) for need for intra-abdominal drain, 1% (95% CI, 0%-3%) for postoperative mortality, 2% (95% CI, 0%-4%) for biliary leakage, 2% (95% CI, 0%-4%) for intra-abdominal abscess, 1% (95% CI, 0%-4%) for biliary stenosis, 1% (95% CI, 0%-3%) for postoperative bleeding, 1% (95% CI, 0%-4%) for pancreatic fistula, 2% (95% CI, 1%-5%) for pulmonary complications, 1% (95% CI, 0%-4%) for paralytic ileus, and 1% (95% CI, 0%-4%) for need for reoperation. Although the available evidence is limited, the findings of the current study might be utilized for hypothesis synthesis in future studies. They can be used to inform surgeons and patients about estimated risks of perioperative complications until a higher level of evidence is available.

• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.79-90
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• 2014

User authentication based on ID and PW has been widely used. As the Internet has become a growing part of people' lives, input times of ID/PW have been increased for a variety of services. People have already learned enough to perform the authentication procedure and have entered ID/PW while ones are unconscious. This is referred to as the adaptive unconscious, a set of mental processes incoming information and producing judgements and behaviors without our conscious awareness and within a second. Most people have joined up for various websites with a small number of IDs/PWs, because they relied on their memory for managing IDs/PWs. Human memory decays with the passing of time and knowledges in human memory tend to interfere with each other. For that reason, there is the potential for people to enter an invalid ID/PW. Therefore, these characteristics above mentioned regarding of user authentication with ID/PW can lead to human vulnerabilities: people use a few PWs for various websites, manage IDs/PWs depending on their memory, and enter ID/PW unconsciously. Based on the vulnerability of human factors, a variety of information leakage attacks such as phishing and pharming attacks have been increasing exponentially. In the past, information leakage attacks exploited vulnerabilities of hardware, operating system, software and so on. However, most of current attacks tend to exploit the vulnerabilities of the human factors. These attacks based on the vulnerability of the human factor are called social-engineering attacks. Recently, malicious social-engineering technique such as phishing and pharming attacks is one of the biggest security problems. Phishing is an attack of attempting to obtain valuable information such as ID/PW and pharming is an attack intended to steal personal data by redirecting a website's traffic to a fraudulent copy of a legitimate website. Screens of fraudulent copies used for both phishing and pharming attacks are almost identical to those of legitimate websites, and even the pharming can include the deceptive URL address. Therefore, without the supports of prevention and detection techniques such as vaccines and reputation system, it is difficult for users to determine intuitively whether the site is the phishing and pharming sites or legitimate site. The previous researches in terms of phishing and pharming attacks have mainly studied on technical solutions. In this paper, we focus on human behaviour when users are confronted by phishing and pharming attacks without knowing them. We conducted an attack experiment in order to find out how many IDs/PWs are leaked from pharming and phishing attack. We firstly configured the experimental settings in the same condition of phishing and pharming attacks and build a phishing site for the experiment. We then recruited 64 voluntary participants and asked them to log in our experimental site. For each participant, we conducted a questionnaire survey with regard to the experiment. Through the attack experiment and survey, we observed whether their password are leaked out when logging in the experimental phishing site, and how many different passwords are leaked among the total number of passwords of each participant. Consequently, we found out that most participants unconsciously logged in the site and the ID/PW management dependent on human memory caused the leakage of multiple passwords. The user should actively utilize repudiation systems and the service provider with online site should support prevention techniques that the user can intuitively determined whether the site is phishing.

• The Journal of Engineering Geology
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• v.15 no.3
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• pp.289-301
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• 2005

Groundwater level drawdown of the first stage resulted from groundwater leakage into tunnel was predicted by an analytical approximation. And numerical modeling was performed to predict the flow rates into tunnel and the groundwater level decline in the vicinity of future proposed tunnel area using a groundwater flow model MODFLOW. Groundwater level of the first stage was predicted to decrease by 15.3 m in analytical approximation. The flow rates in the total length of the future tunnel, when it is excavated, would be approximately $1,870m^3/day$ in numerical model. The model predicts that the groundwater levels in the area around the future tunnel are expected to drop between 5 to 25 m relative to current groundwater levels. Under condition for a $50\%$ tunnel conductance increase, the flow rate was estimated to be $2,518m^3/day$ and the groundwater level drawdown was predicted to be between 5 to 35 m The flow rate and the predicted groundwater level drawdown under a $2,518m^3/day$ tunnel conductance decrease was estimated to be $1,273m^3/day$ and between 2 to 12 m.

• Journal of Energy Engineering
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• v.21 no.1
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• pp.26-32
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• 2012

This study has been performed Thermal Shock test for analyze the cause of Power drop in PV(Photovoltaic) Module. Thermal Shock test condition was performed with temperature range from $-40^{\circ}C{\sim}85^{\circ}C$. One cycle time is 30min. which are consist of low and high temperature 15min. each other. The test was performed with total 500cycles. EL, I-V were conducted every 100cycle up to 500cycles. Mono Cell resulted in 8% Power drop rates in Bare Cell and 9% in Solar Cell. In the case of Multi Cell resulted in 6% Power drop rates in Bare Cell and 13% in Solar Cell. After Thermal Shock test, Solar Cell's Power drop resulted from surface damages, but in the case of Bare Cell's Power drop had no surface damages. Therefore, Bare Cell's Power drop was confirmed as according to leakage current increase by analysis of Fill Factor after Thermal Shock test. Also, Solar Cell's Power drop rates are higher than that of Bare Cell because of surface damages and consuming electric power increase. From now on, it should be considered that analyzed the reasons of Fill Factor decrease and irregular Power drop in PV module and Cell level using cross section, various conditions and test methods.

• Journal of Chest Surgery
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• v.49 no.3
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• pp.165-170
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• 2016

Background: In elderly high-risk surgical patients, sutureless aortic valve replacement (AVR) should be an alternative to standard AVR. The potential advantages of sutureless aortic prostheses include reducing cross-clamping and cardiopulmonary bypass (CPB) time and facilitating minimally invasive surgery and complex cardiac interventions, while maintaining satisfactory hemodynamic outcomes and low rates of paravalvular leakage. The current study reports our single-center experience regarding the early outcomes of sutureless aortic valve implantation. Methods: Between October 2012 and June 2015, 65 patients scheduled for surgical valve replacement with symptomatic aortic valve disease and New York Heart Association function of class II or higher were included to this study. Perceval S (Sorin Biomedica Cardio Srl, Sallugia, Italy) and Edwards Intuity (Edwards Lifesciences, Irvine, CA, USA) valves were used. Results: The mean age of the patients was $71.15{\pm}8.60years$. Forty-four patients (67.7%) were female. The average preoperative left ventricular ejection fraction was $56.9{\pm}9.93$. The CPB time was $96.51{\pm}41.27minutes$ and the cross-clamping time was $60.85{\pm}27.08minutes$. The intubation time was $8.95{\pm}4.19hours$, and the intensive care unit and hospital stays were $2.89{\pm}1.42days$ and $7.86{\pm}1.42days$, respectively. The mean quantity of drainage from chest tubes was $407.69{\pm}149.28mL$. The hospital mortality rate was 3.1%. A total of five patients (7.69%) died during follow-up. The mean follow-up time was $687.24{\pm}24.76days$. The one-year survival rate was over 90%. Conclusion: In the last few years, several models of valvular sutureless bioprostheses have been developed. The present study evaluating the single-center early outcomes of sutureless aortic valve implantation presents the results of an innovative surgical technique, finding that it resulted in appropriate hemodynamic conditions with acceptable ischemic time.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.3
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• pp.7-17
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• 2010

In this paper, an innovative low-power SRAM based on 4-transistor latch cell is described. The memory cells are composed of two cross-coupled inverters without access transistors. The sources of PMOS transistors are connected to bitlines while the sources of NMOS transistors are connected to wordlines. They are accessed by totally new read and write method which results in low operating power dissipation in the nature. Moreover, the design reduces the leakage current in the memory cells. The proposed SRAM has been demonstrated through 16-kbit test chip fabricated in a 0.18-${\mu}m$ CMOS process. It shows 17.5 ns access at 1.8-V supply while consuming dynamic power of $87.6\;{\mu}W/MHz$ (for read cycle) and $70.2\;{\mu}W/MHz$ (for write cycle). Compared with those of the conventional 6-transistor SRAM, it exhibits the power reduction of 30 % (read) and 42 % (write) respectively. Silicon measurement also confirms that the proposed SRAM achieves nearly 64 % reduction in the total standby power dissipation. This novel SRAM might be effective in realizing low-power embedded memory in future mobile applications.

• Korean Journal of Materials Research
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• v.18 no.4
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• pp.169-174
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• 2008

The structural and electrical properties of amorphous $BaSm_2Ti_4O_{12}$ (BSmT) films on a $TiN/SiO_2/Si$ substrate deposited using a RF magnetron sputtering method were investigated. The deposition of BSmT films was carried out at $300^{\circ}C$ in a mixed oxygen and argon ($O_2$ : Ar = 1 : 4) atmosphere with a total pressure of 8.0 mTorr. In particular, a 45 nm-thick amorphous BSmT film exhibited a high capacitance density and low dissipation factor of $7.60\;fF/{\mu}m2$ and 1.3%, respectively, with a dielectric constant of 38 at 100 kHz. Its capacitance showed very little change, even in GHz ranges from 1.0 GHz to 6.0 GHz. The quality factor of the BSmT film was as high as 67 at 6 GHz. The leakage current density of the BSmT film was also very low, at approximately $5.11\;nA/cm^2$ at 2 V; its conduction mechanism was explained by the the Poole-Frenkel emission. The quadratic voltage coefficient of capacitance of the BSmT film was approximately $698\;ppm/V^2$, which is higher than the required value (<$100\;ppm/V^2$) for RF application. This could be reduced by improving the process condition. The temperature coefficient of capacitance of the film was low at nearly $296\;ppm/^{\circ}C$ at 100 kHz. Therefore, amorphous BSmT grown on a TiN substrate is a viable candidate material for a metal-insulator-metal capacitor.

• Journal of Intelligence and Information Systems
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• v.25 no.2
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• pp.1-23
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• 2019

Big data refers to data that is difficult to store, manage, and analyze by existing software. As the lifestyle changes of consumers increase the size and types of needs that consumers desire, they are investing a lot of time and money to understand the needs of consumers. Companies in various industries utilize Big Data to improve their products and services to meet their needs, analyze unstructured data, and respond to real-time responses to products and services. The financial industry operates a decision support system that uses financial data to develop financial products and manage customer risks. The use of big data by financial institutions can effectively create added value of the value chain, and it is possible to develop a more advanced customer relationship management strategy. Financial institutions can utilize the purchase data and unstructured data generated by the credit card, and it becomes possible to confirm and satisfy the customer's desire. CRM has a granular process that can be measured in real time as it grows with information knowledge systems. With the development of information service and CRM, the platform has change and it has become possible to meet consumer needs in various environments. Recently, as the needs of consumers have diversified, more companies are providing systematic marketing services using data mining and advanced CRM (Customer Relationship Management) techniques. KB Kookmin Card, which started as a credit card business in 1980, introduced early stabilization of processes and computer systems, and actively participated in introducing new technologies and systems. In 2011, the bank and credit card companies separated, leading the 'Hye-dam Card' and 'One Card' markets, which were deviated from the existing concept. In 2017, the total use of domestic credit cards and check cards grew by 5.6% year-on-year to 886 trillion won. In 2018, we received a long-term rating of AA + as a result of our credit card evaluation. We confirmed that our credit rating was at the top of the list through effective marketing strategies and services. At present, Kookmin Card emphasizes strategies to meet the individual needs of customers and to maximize the lifetime value of consumers by utilizing payment data of customers. KB Kookmin Card combines internal and external big data and conducts marketing in real time or builds a system for monitoring. KB Kookmin Card has built a marketing system that detects realtime behavior using big data such as visiting the homepage and purchasing history by using the customer card information. It is designed to enable customers to capture action events in real time and execute marketing by utilizing the stores, locations, amounts, usage pattern, etc. of the card transactions. We have created more than 280 different scenarios based on the customer's life cycle and are conducting marketing plans to accommodate various customer groups in real time. We operate a smart offering system, which is a highly efficient marketing management system that detects customers' card usage, customer behavior, and location information in real time, and provides further refinement services by combining with various apps. This study aims to identify the traditional CRM to the current CRM strategy through the process of changing the CRM strategy. Finally, I will confirm the current CRM strategy through KB Kookmin card's big data utilization strategy and marketing activities and propose a marketing plan for KB Kookmin card's future CRM strategy. KB Kookmin Card should invest in securing ICT technology and human resources, which are becoming more sophisticated for the success and continuous growth of smart offering system. It is necessary to establish a strategy for securing profit from a long-term perspective and systematically proceed. Especially, in the current situation where privacy violation and personal information leakage issues are being addressed, efforts should be made to induce customers' recognition of marketing using customer information and to form corporate image emphasizing security.