• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.43-50
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• 2014

In case of all patients who receive radiation therapy, a treatment plan is established and all steps of treatment are planned in the same geometrical condition. In case of head and neck cancer patients who undergo simulated treatment through computed tomography (CT), patients are fixed onto a table for planning, but laid on the top of the treatment table in the radiation therapy room. This study excogitated and fabricated an adjustable holder for head and neck cancer patients to fix patient's position and geometrical discrepancies when performing radiation therapy on head and neck cancer patients, and compared the error before and after adjusting the position of patients due to difference in weight to evaluate the correlation between patients' weight and range of error. Computed tomography system(High Advantage, GE, USA) is used for phantom to maintain the supine position to acquire the images of the therapy site for IMRT. IMRT 4MV X-rays was used by applying the LINAC(21EX, Varian, U.S.A). Treatment planning system (Pinnacle, ver. 9.1h, Philips, Madison, USA) was used. The setup accuracy was compared with each measurement was repeated five times for each weight (0, 15, and 30Kg) and CBCT was performed 30 times to find the mean and standard deviation of errors before and after the adjustment of each weight. SPSS ver.19.0(SPSS Inc., Chicago, IL,USA) statistics program was used to perform the Wilcoxon Rank test for significance evaluation and the Spearman analysis was used as the tool to analyze the significance evaluation of the correlation of weight. As a result of measuring the error values from CBCT before and after adjusting the position due to the weight difference, X,Y,Z axis was $0.4{\pm}0.8mm$, $0.8{\pm}0.4mm$, 0 for 0Kg before the adjustment. In 15Kg CBCT before and after adjusting the position due to the weight difference, X,Y,Z axis was $0.2{\pm}0.8mm$, $1.2{\pm}0.4mm$, $2.0{\pm}0.4mm$. After adjusting position was X,Y,Z axis was $0.2{\pm}0.4mm$, $0.4{\pm}0.5mm$, $0.4{\pm}0.5mm$. In 30Kg CBCT before and after adjusting the position due to the weight difference, X,Y,Z axis was $0.8{\pm}0.4mm$, $2.4{\pm}0.5mm$, $4.4{\pm}0.8mm$. After adjusting position was X,Y,Z axis was $0.6{\pm}0.5mm$, $1.0{\pm}0mm$, $0.6{\pm}0.5mm$. When the holder for the head and neck cancer was used to adjust the ab.0ove error value, the error values from CBCT were $0.2{\pm}0.8mm$ for the X axis, $0.40{\pm}0.54mm$ for Y axis, and 0 for Z axis. As a result of statistically analyzing each value before and after the adjustment the value was significant with p<0.034 at the Z axis with 15Kg of weight and with p<0.038 and p<0.041 at the Y and Z axes respectively with 30Kg of weight. There was a significant difference with p<0.008 when the analysis was performed through Kruscal-Wallis in terms of the difference in the adjusted values of the three weight groups. As it could reduce the errors, patients' reproduction could be improved for more precise and accurate radiation therapy. Development of an adjustable device for head and neck cancer patients is significant because it improves the reproduction of existing equipment by reducing the errors in patients' position.

• The Journal of Internal Korean Medicine
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• v.36 no.3
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• pp.276-283
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• 2015

Objectives: The purpose of this study is to report bowel sound patterns recorded in 3 diseases associated with structural deformity of the pylorus-duodenum. Methods: : Bowel sound recording is a useful non-invasive tool for the evaluation of gastrointestinal motility. However, the difficulty in manual attachment of the electronic stethoscope on the abdominal wall and noise production against bowel sound signals have prohibited its widespread use. Therefore, I developed a new apparatus that eliminates the noise; it contains a sound absorbing device and a holder for the head of stethoscope. Using the new bowel sound recording system, bowel sounds of the patients were recorded repeatedly. The endoscopic and abdominal computed tomography findings were obtained from other hospitals' medical record, and all patients were confirmed to have structural deformity in the pylorus-duodenum. The records of each patient were compared and assessed. Results: : Patients had either duodenal ulcer scar, pyloric stricture, or far advanced malignant stomach cancer, as diagnosed by the gastroscopy. Their dominant frequency of bowel sound obtained from the new system was checked more than 2 times at regular intervals. All 8 recordings in the 2 patients with duodenal ulcer scar (5 times) or pyloric stricture (3 times) showed a decrease in postprandial than fasting dominant frequency. One patient with stomach cancer showed no significant change between postprandial and fasting states at 2 recordings. Conclusions: The analysis of dominant frequency in bowel sounds can indicate the existence of pyloric obstruction that could delay gastric emptying.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2013-2020
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• 2010

This paper presents a study on the modeling for transparent toaster with a cap of folding type. The toaster was modelled to solve problems of customer's unsatisfaction such as heat loss, input of a piece of dirt, unidentified heating state of sliced toaster. Rapid prototyping was followed by the first modeling, and the second modeling was implemented in order to solve the problems of the first modeling such as interference of holder and door, and the third modeling was developed with a cap of folding type through analysis of assembly and simulation. The 3D modeling tool used in this paper was Pro/Engineer 4.0. The modeling was designed to minimize heat loss and structured with transparent outer case. So the toasting procedure will be identified with the naked eye, and the transparent toaster will improve the customer's aesthetic satisfaction.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.26-32
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• 2007

A simple but accurate equivalent circuit of an aperture-coupled cavity-fed microstrip patch antenna is developed. It consists of ideal transformers, admittance elements, and transmission lines, and the related circuit element values are computed by applying the reciprocity theorem and complex power concept with the spectral-domain immittance approach. After validating by the published design example, a dual-band antenna was designed with the help of a hybrid optimization method. For this purpose, the Genetic Algorithm is applied with the Nelder-Mead simplex method. The obtained good results show that this approach turned out to be a very efficient tool for the design of aperture-coupled cavity-fed microstrip patch antenna having various structural design parameters.

• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.65-72
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• 2004

The Internet is a social and economic foundation, apparently destined for human communication and interaction. It is supposed to allow for more interactive and innovative ways for people to do what they do in 'real lift'. There is no shilly-shallying to say that at present, Internet has become a commanding and useful tool for empowerment and income making in developing countries. It is very difficult to say that at present internet has turned into a popular and useful thing among the Bangladeshi people like students, doctors, engineers, businessmen, researchers as well as politician who are being logged into the internet for getting information what they want. Though the Internet was invented in 1970 but it came late in Bangladesh through UUCPs (Unix-to-Unix copy) email connectivity in 1993 and IP connectivity in 1996. Having launched Internet, on June 1996 National polls result were broadcast through the using of World Wide Web (WWW) that was the first ever practice trial in Bangladesh. On June 1996, the government has approved to allow VSAT (Very Small Aperture Terminal) in the country's private sector to operate as Internet Service Provider (ISPs). At the end of year, there were only two ISPs in the country and number of users near about one thousand only. But next year in 1997, the total number of ISPs was more than a dozen and the clientele growth was ten times higher than that of the previous year. From then, the number of Internet users and ISPs are increasing significantly in Bangladesh. About 40 ISP are providing internet service among as many as 3, 20,000 users at present out of almost 130 license holder ISP provider but among the ISPs, most of the ISPs are placed in Dhaka and few are working in Comilla, Sylhet, Rajshahi, Chittagong and Khulna. It should be mention that currently, broadband internet (Radio, Cable) connection is working side by side dial -up connection where broadband accounts 10,000. This paper will have a comprehensive discussion on the current situations of Internet and some of the contemporary issues in the matter concerned.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.3
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• pp.71-92
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• 2016

Service design is a process and methodology for innovating or creating service. This study analyzed library case that applied service design method to library service innovation and creation. The object of this case studies include 7 library such as Copenhagen's municipal library, State Library of Victoria, Carnegie Library of Pittsburgh, Georgia institute of technology library, North carolina state university library. This study analyzed separately to service design requirements, stake-holders, period, process, tools, result and main feature. The implications obtained through this case study are as follows: (1) The design of the library service are focused on user-centered services, future service creation. (2) The service design for library is designed by the collaboration of all stake-holder. (3) From the point of view of period, the service design is continuous, and it has a nature of the project. (4) The service design in library focus on user experience, processes and prototypes development and application. (5) The service design in library are applied to the new tool such as blue print, customer journey map, touch-point, shadow, persona. (6) The purpose of the service design in library is improved and created services, and is has holistic approach.

• Korean Journal of Cognitive Science
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• v.33 no.1
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• pp.51-75
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• 2022

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation that is able to alter neuronal activity in particular brain regions. Many studies have researched how tDCS modulates neuronal activity and reorganizes neural networks. However it is difficult to conclude the effect of brain stimulation because the studies are heterogeneous with respect to the stimulation parameter as well as individual difference. It is not fully in agreement with the effects of brain stimulation. In particular few studies have researched the reason of variability of brain stimulation in response to time so far. The study investigated individual variability of brain stimulation based on circadian rhythm and chronotype. Participants were divided into two groups which are morning type and evening type. The experiment was conducted by Zoom meeting which is video meeting programs. Participants were sent experiment tool which are Muse(EEG device), tdcs device, cell phone and cell phone holder after manuals for experimental equipment were explained. Participants were required to make a phone in frount of a camera so that experimenter can monitor online EEG data. Two participants who was difficult to use experimental devices experimented in a laboratory setting where experimenter set up devices. For all participants the accuracy of 98% was achieved by SVM using leave one out cross validation in classification in the the effects of morning stimulation and the evening stimulation. For morning type, the accuracy of 92% and 96% was achieved in classification in the morning stimulation and the evening stimulation. For evening type, it was 94% accuracy in classification for the effect of brain stimulation in the morning and the evening. Feature importance was different both in classification in the morning stimulation and the evening stimulation for morning type and evening type. Results indicated that the effect of brain stimulation can be explained with brain state and trait. Our study results noted that the tDCS protocol for target state is manipulated by individual differences as well as target state.