• Journal of the Korean Orthopaedic Association
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• v.54 no.6
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• pp.509-518
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• 2019

Purpose: Lymph node metastasis is a very important prognostic factor for all skin cancers and some sarcomas. A sentinel lymph node (SLN) biopsy is the most useful technique for identifying SLNs. Recently, a new generation of diagnostic tools, such as single photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/CT (PET/CT) enabled the detection of SLNs. This study compared the efficacy of PET/CT for detecting lymph node metastases with a SLN biopsy in a single medical center. Materials and Methods: From 2008 to 2018, 72 skin cancers of sarcoma patients diagnosed with some lymph node involvement in a whole body PET/CT reading were assessed. Patients suspected of lymph node metastasis were sent to biopsy and those suspected to be reactive lesions were observed. The analysis was performed retrospectively using the medical records, clinical information, PET/CT readings, and pathology results. Results: The age of patients ranged from 14 to 88 years and the mean follow-up period was 2.4 years. Twenty-two patients were suspected of a lymph node metastasis and confirmed. The sensitivity, specificity, positive predictive value and negative predictive value of PET/CT images in sarcoma and non-sarcoma tumors were increased significantly when the expert's findings were considered together. Conclusion: PET/CT is effective in detecting lymph node metastases.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.3
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• pp.115-122
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• 2022

With the outbreak of COVID-19 a few years ago, video conferencing and electronic document work have increased, and for this reason, the proportion of computer work among modern people's daily routines is increasing. However, as more and more people work on computers in the wrong posture for a long time, the number of patients with poor eyesight and text neck is increasing. Until recently, many studies have been published to correct posture, but most of them have limitations that users may experience discomfort because they have to correct posture by wearing equipment. A posture correction sensor algorithm is proposed to prevent access to the minimum distance between a computer monitor and a person using an ultrasonic sensor device. At this time, an algorithm for minimizing false alarms among warning alarms that sound at the minimum distance is also proposed. Because the ultrasonic sensor device is used, posture correction can be performed without attaching a device to the body, and the user can relieve discomfort. In addition, experimental results showed that accuracy can be improved by reducing false alarms by removing more than half of the noise generated during distance measurement.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.2
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• pp.75-83
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• 2010

Purpose: It aims to evaluate the location change and tendency of hepatic and intrahepatic tumors according to gastric volume and change of location. Materials and Methods: It studied 9 patients with hepatic tumors who visited Gangnam Severance Hospital from March 2009 to April 2010 and who underwent CT or PET (Positron Emission Tomography) within 2 weeks before CT-simulation. The patients fasted for 6 hours before CT-simulation and drank 240~250 cc of water just before CT or PET for image fusion. Those two types of images were fused to RTP (Radiation Treatment Planning, Pinnacle 8.0h) focusing on bone structure of individual patients. Results: They drank 240~260 cc of water but their stomach volume after drinking water varied from 259.3 cc to 495.4 cc. Even though individual differences existed in the change of stomach volume before and after drinking water, the volume was increased by 130 cc (174%) on average. The change in absolute distance between the centers of tumors ranged from 0.52 cm to 3.04 cm (1.52 cm on average); from 0.1 cm to 1.35 cm (0.44 cm on average) in cranial-caudal direction; from 0.05 cm to 2.75 cm (1.22 cm on average) in left-right direction; and from 0.05 cm to 1.85 cm (0.33 cm on average) in ventral-dorsal direction. Conclusion: It is hard to predict the movement of tumors by observing stomach movement, due to great individual differences; however, it was observed that the location of hepatic tumors was right-sided as the stomach was filled with water. Thus, it is recommended to maintain the fastened state to secure the accuracy of hepatic tumor treatment. If it cannot maintain the fastened state, it is recommended to measure stomach volumes and movement in the patient to consider the movement of hepatic tumors before radiation treatment.

• Journal of the Korean Professional Engineers Association
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• v.19 no.2
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• pp.10-20
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• 1986

This paper describes a countermeasure of electric utilities and customer equipment in order to minimize an effect of sensitive electrical and electronic equipment on the voltage disturbances. After being studied, some schemes to solve were discovered. Firstly, in the electric utilities, the reduction of frequency and influence of voltage drop's time are not easy to realize because of the standpoint of effect and economy. Secondly, in the customer equipment, there are some equipment to minimize the voltage disturbances, Such as an UPSs, a noise suppressors and a power conditioners. One of them should be established on the computer control and automated systems, the electromagnetic switch of delay-release type should be adopted on the electromagnetic switch, the controlling circuit should be adopted on the variable speed motors which is being considered a countermeasure for a momentary under-voltage drops, the luminaire adhering a instantaneous restrike device should be adopted on the HID lamp. And also, the scheme of extending a setting time of relay on the undervoltage relay and the forming method of sequence which is automatic reclosing at this time of instantaneous suspension of an electric supply have been studied.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.135-142
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• 2017

Adoption of CAD/CAM milling in dentistry has allowed production of more analytic and precise prosthesis. Such precision enables definite path of insertion and undercut to be provided in removable partial denture especially when designing a surveyed crown on an abutment tooth. This case is about the production of surveyed crown with proper path of insertion utilizing CAD/CAM electronic surveying method on a patient with edentulous maxilla. Resulting removable partial denture fit well and showed acceptable stability and retention with no clinical problem.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.4
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• pp.9-15
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• 2012

With the rise of internet and e-commerce, this is more applicable now than ever. People rely on computer networks to provide them with news, stock prices, e-mail and online shopping. People's credit card details, medical records and other personal information are stored on computer systems. Many companies have a web presence as an essential part of their business. The research community uses computer systems to undertake research and to disseminate findings. The integrity and availability of all these systems have to be protected against a number of threats. Amateur hackers, rival corporations, terrorists and even foreign governments have the motive and capability to carry out sophisticated attacks against computer systems. Therefore, the field of information and communication security has become vitally important to the safety and economic well being of society as a whole. This paper provides an overview of IDS and IPS, their functions, detection and analysis techniques. It also presents comparison of security capability and characteristics of IDPS techniques. This will make basis of IDPS(Intrusion Detection and Protection System) technology integration for a broad-based IDPS solutions

• Journal of Digital Contents Society
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• v.8 no.3
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• pp.403-410
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• 2007

The P2P(Peer to Peer) business, which has brought the great wave all over the world, was made possible as a user's environment is getting improved through the introduction of high-tech PC, and the access service of high-speed internet. P2P is the form that anyone using computer could be both a provider and a user by searching or connecting to the personal computer each other out of the concept of server and client. In other words, it is the system made by the technique which could share the data connecting between the PC of the person with the information and the person searching the information. Recently a various system of P2P is under the development which could be applied to the electronic commerce among the companies which is not only the file share among the individuals. In this paper, we propose the more effective electronic business system making use of P2P.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.4
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• pp.85-97
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• 1999

A blind signature scheme is a protocol allowing verifier to obtain a valid signature for a message m from a signer without him seeing the message. This means that the bank in collaboration with the shop cannot trace the electronic cash to user. However anonymous electronic cash also facilitates fraud and criminal acts such as money laundering anonymous blackmailing and illegal purchaes. Therefore in this paper we propose fair blind signature scheme based on KCDSA which is a domestic digital signature scheme and it apply a electronic cash system. In particularly a proposed electronic cash system have an anonymity control ability which trace a user who make use a electronic cash illegally in association with a trusted center.

• Proceedings of the Technology Innovation Conference
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• 2005.08a
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• pp.189-216
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• 2005

본 연구는 혁신과정에 중대한 영향을 미치는 혁신네트워크를 혁신과정을 둘러싼 제반 지식흐름과 이러한 지식흐름의 네트워크로 재정의하고, 지식흐름과 지식네트워킹 차원에서 접근하였다. 이러한 차원에서, 지식흐름의 대리변수로 간주되는 특허인용데이터를 활용하여 한국의 혁신주체를 둘러싼 지식네트워킹의 특성을 분석하는 방식으로 혁신네트워크를 분석했다. 그 결과, 한국의 기술혁신의 수준이 강화되면서 한국의 지식네트워킹 수준도 제고되었지만, 기술선진국과 비교할 때 상당히 미약한 수준임이 확인할 수 있었다. 또한 기술분야별로 보면 전기전자와 컴퓨터통신에서만 지식네트워킹이 상대적으로 활발하고 여타 기술부문에서는 상대적으로 저조하여 지속적인 기술혁신에 장애로 작용할 가능성이 크다. 동종기술과 이종기술로 구분하는 경우 여전히 동종기술간 지식흐름이 이종기술간 지식흐름을 압도하고 있어서 융합추세의 국제적 트렌드를 반영하고 있지 못하는 한계를 보였다. 이들 지식네트워크는 혁신기업이 주도하고 있는데, 그 방식은 주로 기업과 기업간 유형이 보다 지배적이었음을 알 수 있다. 따라서 최소한 특허인용데이터로 볼 때 대학과 연구소 등 비기업과의 지식네트워킹에 비해, 기업과의 네트워킹이 보다 지배적임을 알 수 있는데, 이것은 국내외를 막론하고 적용되었다. 한국 혁신시스템의 취약한 고리인 네트워킹의 저조를 개선하기 위해선, 기술부문간 차별적인 네트워킹 정책이 세심하게 입안되어야 한다. 이때 한국에서 가장 파급효과가 높은 혁신주체는 대학이 아니라 대기업이라는 점이 적극 고려되어야 한다.. 제안하는 시스템의 신뢰도 측정 방법은 부분이 가지고 있는 신뢰도가 전체 신뢰도에 미치는 영향을 산술적으로 측정할 수 있어 시스템이 요구하는 신뢰도에 접근할 수 있는 방법과 근거를 제공하는 장점이 있다.소시키는 장점을 갖는다.것으로 조사되었으며 40대 이상의 연령층은 점심비용으로 더 많은 지출을 하고 있는 것으로 나타났다. 4) 끼니별 한식에 대한 선호도는 아침식사의 경우가 가장 높았으며, 이는 40대와 50대에서 높게 나타났다. 점심 식사로 가장 선호되는 음식은 중식, 일식이었으며 저녁 식사에서 가장 선호되는 메뉴는 전 연령층에서 일식, 분식류 이었으며, 한식에 대한 선택 정도는 전 연령층에서 매우 낮게 나타났다. 5) 각 연령층에서 선호하는 한식에 대한 조사에서는 된장찌개가 전 연령층에서 가장 높은 선호도를 나타내었고, 김치는 40대 이상의 선호도가 30대보다 높게 나타났으며, 흥미롭게도 30세 이하의 선호도는 30대보다 높게 나타났다. 그 외에도 떡과 죽에 대한 선호도는 전 연령층에서 낮게 조사되었다. 장아찌류의 선호도는 전 연령대에서 낮았으며 특히 30세 이하에서 매우 낮게 조사되었다. 한식의 맛에 대한 만족도 조사에서는 연령이 올라갈수록 한식의 맛에 대한 만족도는 낮아지고 있었으나, 한식의 맛에 대한 만족도가 높을수록 양과 가격에 대한 만족도는 높은 경향을 나타내었다. 전반적으로 한식에 대한 선호도는 식사 때와 식사 목적에 따라 연령대 별로 다르게 나타나고 있으나, 선호도는 성별이나 세대에 관계없이 폭 넓은 선호도를 반영하고 있으며, 이는 대학

• The Journal of Korean Institute for Practical Engineering Education
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• v.1 no.1
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• pp.99-105
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• 2009

Computer-based learning with the access to World Wide Web has become a fundamental base for adopting beneficial education. It provides significant facilities such as animation and interactive processes that are not possible with textbooks. Web/Internet-enabled applications which is fully controlled and monitored from remote locations are extensively used by a number of Universities, national laboratories and companies for different kinds of applications all over the world. Continuous advances in computers and electronics coupled with drooping prices of hardware have made Web/Internet-based technologies less costly than before, particularly for educational organizations. Thus, it is more affordable to invest in these technologies that are essential for both expanding education over Web and further improving and advancing such technologies the application of remote virtual instruments will be demonstrated in this context along with experiments that can be adopted to be educational experimental lab for Engineering Education students.