• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.149-168
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• 2015

In cognitive radio networks (CRNs), hybrid overlay and underlay sharing transmission mode is an effective technique for improving the efficiency of radio spectrum. Unlike existing works in the literature, where only one secondary user (SU) uses overlay and underlay modes, the different transmission modes should be allocated to different SUs, according to their different quality of services (QoS), to achieve the maximal efficiency of radio spectrum. However, hybrid sharing mode allocation for heterogeneous services is still a challenge in CRNs. In this paper, we propose a new resource allocation method for hybrid sharing transmission mode of overlay and underlay (HySOU), to achieve more potential resources for SUs to access the spectrum without interfering with the primary users. We formulate the HySOU resource allocation as a mixed-integer programming problem to optimize the total system throughput, satisfying heterogeneous QoS. To decrease the algorithm complexity, we divide the problem into two sub-problems: subchannel allocation and power allocation. Cutset is used to achieve the optimal subchannel allocation, and the optimal power allocation is obtained by Lagrangian dual function decomposition and subgradient algorithm. Simulation results show that the proposed algorithm further improves spectrum utilization with a simultaneous fairness guarantee, and the achieved HySOU diversity gain is a satisfactory improvement.

• 성인간호학회지
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• 제14권3호
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• pp.418-427
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• 2002

Purpose: The Purpose of this research was to develop the integrative exercise program for the elderly. Method: The first step was to survey the elder's health status and general health problems. The second step was to design the exercise type, intensity, time and frequency. Result: 1. Elders who implement the integrative exercise program had weaker health status, lower physical performance and more depression than any other places. 2. The integrative exercise program developed the preparation stage composed of stretching and Yudongkong-Ki exercise, the central stage was composed of range of motion exercise, muscle strength exercise and aerobic exercise with favorite and popular Korean music. The finishing stage was composed of joint rounding and Yudongkong-Ki exercise. The exercise intensity was RPE(rating perceived exertion) 10-11, maximal pulse rate 40-60%, duration started from 20min to 50min and frequency is 2-3times/wk. Conclusion: The integrative exercise program developed by the researcher is tailored exercise that is more applicable to individual cases in community settings. Eventually, the program is safely applicable to the elders, and is expected to improve the elders' physical function and quality of life.

• 한국멀티미디어학회논문지
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• 제14권8호
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• pp.965-980
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• 2011

In this paper, the use of conditional Fuzzy C-Means (CFCM) aimed at estimation of desired states of an unknown digital communication channel is investigated for blind channel equalization. In the proposed CFCM, a collection of clustered centers is treated as a set of pre-defined desired channel states, and used to extract channel output states. By considering the combinations of the extracted channel output states, all possible sets of desired channel states are constructed. The set of desired states characterized by the maximal value of the Bayesian fitness function is subsequently selected for the next fuzzy clustering epoch. This modification of CFCM makes it possible to search for the optimal desired channel states of an unknown channel. Finally, given the desired channel states, the Bayesian equalizer is implemented to reconstruct transmitted symbols. In a series of simulations, binary signals are generated at random with Gaussian noise, and both linear and nonlinear channels are evaluated. The experimental studies demonstrate that the performance (being expressed in terms of accuracy and speed) of the proposed CFCM is superior to the performance of the existing method exploiting the "conventional" Fuzzy C-Means (FCM).

• Journal of information and communication convergence engineering
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• 제8권6호
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• pp.609-617
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• 2010

This paper is concerned with the use of a selforganizing map (SOM) to estimate the desired channel states of an unknown digital communication channel for blind equalization. The modification of SOM is accomplished by using the Bayesian likelihood fitness function and the relation between the desired channel states and channel output states. At the end of each clustering epoch, a set of estimated clusters for an unknown channel is chosen as a set of pre-defined desired channel states, and used to extract the channel output states. Next, all of the possible desired channel states are constructed by considering the combinations of extracted channel output states, and a set of the desired states characterized by the maximal value of the Bayesian fitness is subsequently selected for the next SOM clustering epoch. This modification of SOM makes it possible to search the optimal desired channel states of an unknown channel. In simulations, binary signals are generated at random with Gaussian noise, and both linear and nonlinear channels are evaluated. The performance of the proposed method is compared with those of the "conventional" SOM and an existing hybrid genetic algorithm. Relatively high accuracy and fast search speed have been achieved by using the proposed method.

• 한국동물위생학회지
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• 제22권2호
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• pp.135-149
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• 1999

This study was concerned with assessment of dietynitrosamine (DEN) induced liver cell carcinogenesis by measurement of changes preceding the development of neoplasms. The changes of hepatic morphology in rats(Sprague-Dawley) were detected by hematoxylin-eosin stain and immunohistochemistry(PCNA). The results were as follows ; 1. Minor behavioral change, brittleness of hair and decreased amount of water and diet intake. were observed in rats 7 weeks after DEN administration. 2. Variable size of liver tumor and hepatomegaly were observed in rats treated with DEN after 10 weeks. 3. Numerous vacuoles were showed on the midzonal and or peripheral areas of hepatic lobules. The large and polymorphological hepatocytes with eosinophilic cytoplasm or densely basophilic mitotic nucleoli were showed. 4. Several proliferative small round cells were shown on vacuolated and necrotic areas in peripheral hepatic lobules or portal areas. 5. PCNA-positive cells were showed on the vacuolated portal areas and peripheral areas of hepatic lobules. Maximal positivity was 23.6% in the areas of small round cells. In conclusion, this result confirmed that the DEN was one of the potent hepatocarcinogens. In histopathological analysis, the altered foci, hyperplastic nodules, neoplastic nodules, adenomas and carcinomas were observed in liver tumors induced by administration of DEN in rats.

• 비파괴검사학회지
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• 제29권3호
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• pp.224-229
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• 2009

An experimental study was conducted to investigate the effects of turtle neck syndrome, so called, on muscular fatigue and muscle activity. Six subjects (males) participated and performed the prolonged casual computer work in the study. EMG signals from six muscles of the dominant neck-back region were acquired and recorded for 10 seconds at the beginning and the end of three hours computer work. EMG was recorded from six muscles by using a computerized data recording and analysis system. Power spectrum function of EMG was calculated off-line by means of a signal processing software package. Power spectrum functions were smoothed with a moving average filter of 21 points and normalized with respect to the maximal value achieved during the trials. Muscle activity and median frequencies of Sternocleidomastoid(SCM) in turtle neck posture was approximately 51%, which were less than those in normal neck posture. SCM also showed the biggest decrease in median frequency. Results will provide the insight into the neck-back injury mechanism of turtle neck patients. Furthermore, they will be helpful in developing rehabilitation programs for restoring patients' neck-back functions.

• 대한인간공학회지
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• 제26권2호
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• pp.21-33
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• 2007

The study investigates the effects of luminance contrast, which is the contrast between text color and background color, on readability in VDT environments. Our research goals are to prove that the relationship between luminance contrast and readability is not linear and to explore the best luminance contrast level for optimal readability. We conducted two pretests before the main experiment to determine the operational readability and luminance contrast levels. We also conducted a controlled main experiment, in which luminance contrast, reading amount and screen size were tested in terms of its relation with readability. The results of the main experiment indicate that the readability has a non-linear relation with luminance contrast, and the optimal readability is obtained when the contrast is equal to 0.951. Furthermore, the non-linear function and optional point stay constant regardless of screen size and reading amount. The paper ends with implications of the results that maximal contrast does not always mean the optimal readability.

• 한국CDE학회논문집
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• 제14권5호
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• pp.297-305
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• 2009

Automatic generation of the mid-surfaces of a CAD model is becoming a useful function in that it can help increase the efficiency of engineering analysis as far as it does not affect the result seriously. Several methods had been proposed previously to automatically generate the mid-surfaces, but they often failed to generate the mid-surfaces of complex CAD models. Due to the inherent difficulty of this mid-surface generation problem, it may not be possible to come up with a complete and general method to solve this problem. Since a method that can handle a specific case may not work for different cases, it seems that developing case-specific methods ends up with solving only a fraction of the problem. In this paper, therefore, we propose a method to generate mid-surfaces based on a divide-and-conquer paradigm. This method first decomposes a complex CAD model into simple volumes. The mid-surfaces of the simple volumes are automatically generated by the existing methods, and then they are converted into the mid-surfaces of the original CAD model.

• The Korean Journal of Physiology
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• 제11권2호
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• pp.41-43
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• 1977

In pulmonary function which is important place which national physical power, in maximal grade of physical power, and end growth and development whom aged 20 years old that whole members 74 students, and taken pulmonary functions examination records, and took as the following results. 1) Frequency of breathing: Pertaining of the frequency of breathing are about form 15, to 16 times per minute at male and female students. 2) Vital capacity: Measures of vital capacity are in case of male students, whom was about 4.3 liter, and female students was about 3.6, liter which different between male and female students was more low quantity at female students with comparison male students. 3) Tidal volume: Pertaining of the volume are in case of male students, whom was 521ml, and female students was 497m1, and was slightly low quantity at female students with comparison male students, 4) Breathing holding time: Breathing holding time are in case of male students, whom was 64 sec, and female students was 55 sec, and was sbout 10 sec more high quantity at male students than female students.

• Journal of Communications and Networks
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• 제6권1호
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• pp.68-77
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• 2004

In the near future packet networks should support applications which can not predict their traffic requirements in advance, but still have tight quality of service requirements, e.g., guaranteed bandwidth, jitter, and packet loss. These dynamic characteristics mean that the sources can be made to modify their data transfer rates according to network conditions. Depending on the customer&; needs, network operator can differentiate incoming connections and handle those in the buffers and the interfaces in different ways. In this paper, dynamic QoS-aware scheduling algorithm is presented and investigated in the single node case. The purpose of the algorithm is in addition to fair resource sharing to different types of traffic classes with different priorities ?to maximize revenue of the service provider. It is derived from the linear type of revenue target function, and closed form globally optimal formula is presented. The method is computationally inexpensive, while still producing maximal revenue. Due to the simplicity of the algorithm, it can operate in the highly nonstationary environments. In addition, it is nonparametric and deterministic in the sense that it uses only the information about the number of users and their traffic classes, not about call density functions or duration distributions. Also, Call Admission Control (CAC) mechanism is used by hypothesis testing.