• Journal of Communications and Networks
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• 제11권2호
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• pp.148-156
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• 2009

The fixed spectrum assignment policy in today's wireless networks leads to inefficient spectrum usage. Cognitive radio network is a new communication paradigm that enables the unlicensed users to opportunistically use the spatio-temporally unoccupied portions of the spectrum, and hence realizing a dynamic spectrum access (DSA) methodology. Interference temperature model proposed by Federal Communications Commission (FCC) permits the unlicensed users to utilize the licensed frequencies simultaneously with the primary users provided that they adhere to the interference temperature constraints. In this paper, we formulate two NP-hard optimal scheduling methods that meet the interference temperature constraints for cognitive radio networks. The first one maximizes the network throughput, whereas the second one minimizes the scheduling delay. Furthermore, we also propose suboptimal schedulers with linear complexity, referred to as maximum frequency selection (MFS) and probabilistic frequency selection (PFS). We simulate the throughput and delay performance of the optimal as well as the suboptimal schedulers for varying number of cognitive nodes, number of primary neighbors for each cognitive node, and interference temperature limits for the frequencies. We also evaluate the performance of our proposed schedulers under both additive white gaussian noise (AWGN) channels and Gilbert-Elliot fading channels.

• 스마트미디어저널
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• 제1권1호
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• pp.17-26
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• 2012

무선인지 네트워크에서 비면허 사용자는 면허 스펙트럼 대역을 감지하여 가회가 있을 때마다 면허 사용자에 간섭을 일으키지 않고 매체에 접근한다. 특히 애드혹 네트워크에서는 MAC 계층이 비면허 사용자들간 스펙트럼 접근을 조정하는 중요한 역할을 수행한다. 이에 따라 최근 많은 MAC 프로토콜이 연구되고 있다. 본 논문에서는 무선인지 애드혹 네트워크에서의 MAC 프로토콜을 비교 분석한다. 먼저 프로토콜들을 공통 제어 채널을 기준으로 분류하고 각 종류별 주요 프로토콜을 분석한다. 그리고 나서 프로토콜들을 고유 특성과 성능 측면에서 정성적으로 비교한다.

• 의료법학
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• 제15권1호
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• pp.11-34
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• 2014

Promulgation of the medical practice rule without specific definition in Medical Law has brought about many constitutional issues. The major issue is that the law has the government punish unlicensed medical practice without defining what it is. Instead, the law chooses a license-centered structure of criminal punishment for medical malpractice, saying "no one can practice medicine without the government-approved license." This regulation violates the rule of "void for vagueness" based on the principle of "nulla poena nullum crimen sine lege." Judicial interpretation should be required for a citizen to understand the Medical Law provision intuitively. In addition, the law infringes upon the freedom of occupation of the unlicensed and the licensed who wish to extend his or her practice area for "holistic medicine." The central issue of the law is that it was established under no ground of professionalism even though medical practice has been understood professional. The government has centrally controlled the medical field for its needs. Lastly, the current law violates the right of medical selection of the consumers of medicine. Because patients have the right of health and life, they have to hold the latitude of selection for medical treatments. Especially, they should have an opportunity for considering the Complementary and Alternative Medicine if they want. But under the current rules, this medicine is not permitted. To correct those problems, a new provision for the definition of medical practice should be adopted at once.

• 한국치위생학회지
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• 제13권2호
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• pp.211-220
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• 2013

Objectives : This study intended to figure out illegal treatment by unlicensed person in dental area and factors, which were considered as user's position on the basis of the local community investigation of health conditions in chungbuk provinces in 2008. Methods : This study used chi-square test and complex sample design of multi-variate logistic regression analysis to question 12,443 peoples who have experience on illegal dental treatment. Results : Multi-variate logistic regression analysis results showed that factors having related to illegal dental treatment are sex, age, education standards, subjective awareness of oral health condition, drinking experience of lifetime, unmet need of dental treatment, chewing difficulty, use of dentures, experience of scaling and the use of interdental care instrument. Conclusions : As a result of this study, in order to root out illegal dental treatment, we need to expand the breadth of health insurance coverage so that it can reduce the burden of dental expenses. Moreover, we need to set out health service of public oral health to inform the importances of maintaining good oral health and the problems of illegal dental treatment by unlicensed person.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권5호
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• pp.1532-1553
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• 2014

Radio spectrum is a precious resource and characterized by fixed allocation policy. However, a large portion of the allocated radio spectrum is underutilized. Conversely, the rapid development of ubiquitous wireless technologies increases the demand for radio spectrum. Cognitive Radio (CR) methodologies have been introduced as a promising approach in detecting the white spaces, allowing the unlicensed users to use the licensed spectrum thus realizing Dynamic Spectrum Access (DSA) in an effective manner. This paper proposes a generalized framework for DSA between the licensed (primary) and unlicensed (secondary) users based on Continuous Time Markov Chain (CTMC) model. We present a spectrum access scheme in the presence of sensing errors based on CTMC which aims to attain optimum spectrum access probabilities for the secondary users. The primary user occupancy is identified by spectrum sensing algorithms and the sensing errors are captured in the form of false alarm and mis-detection. Simulation results show the effectiveness of the proposed spectrum access scheme in terms of the throughput attained by the secondary users, throughput optimization using optimum access probabilities, probability of interference with increasing number of secondary users. The efficacy of the algorithm is analyzed for both imperfect spectrum sensing and perfect spectrum sensing.

• 한국응급구조학회지
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• 제25권2호
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• pp.169-186
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• 2021

Purpose: This study aimed to analyze the data from public information disclosure about pre-hospital advanced airway management and identify the problem by considering domestic laws and guidelines. Methods: Data were collected between 2017 and 2018 and analyzed using SPSS 25.0. Then, the problems of the analysis results based on the relevant laws and practical guidelines were reviewed. Results: The review of domestic laws and practice guidelines revealed that ambulance nurses can implement supraglottic airway device only under the following three conditions: ① smart advanced life support pilot project area, ② trained to insert I-Gel, and ③ member of a special ambulance. In total, 21,574 cases of advanced airway management (endotracheal intubation: 2,428, I-Gel: 18,502, LMA : 499, KING AIRWAY: 144) were reported. In many cases, advanced airway management was performed by ambulance nurses who did not meet the above conditions, which was in violation of laws and guidelines. In addition, the prognosis of intubated patients was not followed up. Conclusion: The Korea National Fire Agency must stop all unlicensed medical practice by untrained, uneducated, and uncertified nurses and demand quality control programs for intubated patients.

• ETRI Journal
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• 제43권1호
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• pp.7-16
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• 2021

Noncontiguous orthogonal frequency division multiplexing (NC-OFDM)-based cognitive radio (CR) systems achieve highly efficient spectrum utilization by transmitting unlicensed users' data on subcarriers of licensed users' data when they are free. However, there are two disadvantages to the NC-OFDM system: out-of-band power (OBP) and a high peak-to-average power ratio (PAPR). OBP arises due to side lobes of an NC-OFDM signal in the frequency domain, and it interferes with the spectrum for unlicensed users. A high PAPR occurs due to the inverse fast Fourier transform (IFFT) block used in an NC-OFDM system, and it induces nonlinear effects in power amplifiers. In this study, we propose an algorithm called "Alternative Projections onto Convex and Non-Convex Sets" that reduces the OBP and PAPR simultaneously. The alternate projections are performed onto these sets to form an iteration, and it converges to the specified limits of in-band-power, peak amplitude, and OBP. Furthermore, simulations show that the bit error rate performance is not degraded while reducing OBP and PAPR.

• 의료법학
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• 제24권1호
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• pp.3-42
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• 2023

대법원 2022. 12. 22. 선고 2016도21314 전원합의체 판결은 한의사가 진단용 초음파기기를 사용하여 자궁내막증식증을 진단한 것이 무면허의료행위가 아니라고 판단하였다. 이 판결은 서양의학에 속하는 영상의학적 방법을 사용한 특정 의료행위가 무면허의료행위가 아니라고 판단한 것이 아니라 진단용 초음파기기 사용만으로 서양의학에 속하는 영상의학적 진단행위가 있었다고 단정할 수 없고 그러한 사정은 검사가 구체적으로 특정하여 기소하고 증명하여야 함을 분명히 하는 취지라고 할 수 있고, 그러한 한 타당하다. 한의학계에서 주장해온 바와 같이 특정 기기 사용 자체를 금지하는 규정은 없는 것이다. 그러나 당해 사안에서 실제로 서양의학에 속하는 영상의학적 진단방법을 사용하였을 가능성이 상당하고 그러한 경우 무면허의료행위임 또한 분명하다. 지금까지 의료와 한방의료의 경계획정이 문제된 사안 중 상당수가 시험적 성격을 띤 반면, 위 사건의 의료행위는 다수의 한의원에서 널리 행해지고 있다고 의심된다는 점에서 일정한 대응이 필요하다. 나아가 실제로 서양의학에 속하는 영상의학적 진단방법을 쓴 것이 아니라 하더라도 여전히 문제가 있다. 다수의 한의원이 전체적으로 진단에 관한 한 서양의학에 속하는 영상진단을 하는 것처럼 오인하기 쉽게 하고 있는바, 이는 부정경쟁행위이자 의료 소비자의 실질적 선택권을 침해하는 행위이기 때문이다. 현행법상 무면허의료행위만으로 이 문제에 대응하는 데는 한계가 있을 뿐 아니라 장차 무면허의료행위 규율을 개선하는 방법으로 대응하는 것도 쉽지 아니하다. 별도의 규율장치를 도입할 필요가 있다.

• 대한치과기공학회지
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• 제34권4호
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• pp.433-445
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• 2012

Purpose: In order to validate empirically the theoretical model of this study subjects, who were limited in Andong gun, Youngyang gun, Uiseong gun, Bonghwa gun, Chilgok gun, Cheongsong gun according to residence-specified distribution and over aged 65, were focused to the elderly in rural areas with geographical characteristics where they have difficulties in accessibility of dental facilities and dental care. Methods: The collected data were analyzed by the SPSS 19.0 program. First, the frequency analysis was performed for each independent variable and the dependent variable. Second, reliability analysis and correlation analysis were conducted for daily living skills and Biomedical Vigilance. Third, multivariate analysis was performed in terms of and the post-administration management. Fourth, multiple regression analysis was performed to identify the factors affecting the post-management of dentures and the period of using dentures. Results: By results of the multiple regression analysis, the elder the subjects are(${\beta}$ = 0.03), the lower their income activities are(${\beta}$ = -0.18), the smaller their monthly allowances are(${\beta}$ = -0.16), the worse their daily activity skills are(${\beta}$ = -0.12), the more they were mounted their dentures by an unlicensed contractor(${\beta}$ = 0.07), and the more they cost to their dentures(${\beta}$ = 0.14), the longer the period of use dentures are. And the beneficiaries of Basic Livelihood Security(${\beta}$ = -0.14) who got free denture business are shorten the period of using dentures. According to multiple regression analysis for post management of dentures, the independent variables like the health education(${\beta}$ = 0.24), smoking(${\beta}$ = -0.18), periodic oral examination(${\beta}$ = 0.13), dentures mounted by an unlicensed contractor(${\beta}$ = -0.13) are shown statistically significant results. In that study subjects are taking part in health education and non-smokers, they are likely to have more chances to post management for their dentures like periodic oral examination. However the subjects who were weared their denture by an unlicensed contractor get less chance to post management for their dentures. Conclusion: As the elderly who want to wear denture are increasing due to the denture insurance for the elderly, the need for oral health education for the elderly is an urgent request, especially continuos education for the way of use their dentures and follow-up management for the elderly who were already mounted their dentures. And also, the need for more systematic researches is requested for securing objective data.

• Journal of Communications and Networks
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• 제5권4호
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• pp.290-302
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• 2003

Ultra wide band (UWB) radio has recently attracted increased attention due to its expected unlicensed operation, and potential to provide very high data rates at relatively short ranges. In this article we briefly describe some main candidate multiple access and modulation schemes for UWB communications, followed with their power spectral density calculation and properties. We also present some illustrative capacity results, and provide a discussion of the impact of network topology on multiple access capacity.