• Journal of IKEEE
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• v.4 no.2 s.7
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• pp.257-265
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• 2000

Turbo Code decoder is an iterate decoding technology, which extracts extrinsic information from the bit to be decoded by calculating both forward and backward metrics in each decoding step, and uses the information to the next decoding step. Viterbi decoder, which is for a convolutional code, runs continuous mode, while Turbo Code decoder runs by block unit. There are algorithms used in a decoder : which are MAP(maximum a posteriori) algorithm requiring very complicated calculation and SOVA(soft output Viterbi algorithm) using Viterbi algorithm suggested by Hagenauer, and it is known that the decoding performance of MAP is better. The result of this make experimentation shows that the performance of SOVA, which has half complex algorithm compare to MAP, is almost same as the performance of MAP when the SOVA decoding performance is supplemented with Robust equalization techniques.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.12
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• pp.1416-1426
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• 2008

In this paper, we present a small size and multiband directional dipole antenna for mobile communication repeaters. In the omni-directional dipole antenna, a planar reflector under the dipole provides improved directivity in front-direction with wide beamwidth. In order to miniaturize the directive dipole, the size of the reflector is reduced. A vertical stub on the reflector is proposed to enhance the front-directivity of the radiation pattern and mitigate the backward radiation due to the reduced reflector. Furthermore, we use horizontal stubs on edge of vertical stub to obtain additional reduction of the antenna size. To meet the current demand of wireless communication service, the designed antenna shows wideband characteristic by employing electromagnetic coupled two-dipoles with dual-resonance frequencies.

• Journal of the Economic Geographical Society of Korea
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• v.2 no.1_2
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• pp.123-144
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• 1999

This paper examines the change of quality of life in the Integrated Yosu City and suggests the directions of urban development. Research into the quality of life in local and region scale is interesting both from the point of view of theory and practice, and has attracted much attention in the social sciences since the 1960s. This study is an attempt to examine the change of the quality of hie in the Integrated Yosu City. In the overall assessment of the level of satisfaction about the quality of life during the past five years, most of the respondents have positive evaluation of the changes of quality of urban life. In particular, the quality of living facilities, urban administration and convenience services has relatively improved during the past five years. On the other hand, the quality of physical environment. art and cultural opportunities, transportation options has been backward during the past five years. Therefore, the directions of urban development of the Integrated Yosu City may be summarized as follows: the establishment of a wide transportation network system, waterfront development, the activation of tourism industry and harbor works, the preparation of an urban landscape, the citizens'campaign for a community culture.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.667-673
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• 1996

The prevalence of class III malocclusion is approximately 5$\sim$9%, and about one fourth of this malocclusion is due to underdeveloped maxilla. Maxillary protraction appliance is an orthopedic device which promote the growth of a deficient maxilla by applying extraoral force to actively growing patients. The object of using maxillary protraction appliance is to guide a normal growth of maxilla and mandible and improve the occlusal relationship and also improve the facial profile. The author treated three patients whom were diagnosed as a class III malocclusion due to deficient maxilla using maxillary protraction appliance and the followings are the conclusions : 1. In these cases, anterior crossbite was corrected by anterior movement of maxilla and downward backward rotation of mandible and simultaneously, anterior facial height was increased. 2. The amount of dental change compare to skeletal change was greater as the patients got older. 3. When 500gm of force to each side was applied, the treatment period has been decreased. 4. As a result of applying the force between maxillary first primary molar and canine, there was a small degree of changes in palatal plane. So, it can be concluded that the maxillary protraction appliance is effective in treating growing patients with a deficient maxilla.

• Korean Journal of Occupational Health Nursing
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• v.6 no.1
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• pp.53-71
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• 1997

Across sectional study was performed to evaluate the chronic effects on central nerve system(CNS) of cumulative exposure of complex organic solvents, using neurobehavioral test. Subjects were 66 (male) dock yard painters of some large ship industry which is located in Ulsan. The neurobehavioral test battery used in this study was NCTB (Neurabehavioral Core Test Battery recommended by WHO(World Health Organization), which consisted of 7 items-Profile of mood states (POMS), Simple reaction time, Santa Ana dexterity test. Digit span, Digit symbol, Benton visual retention test and Pursuit aiming. The subjects were classified by 3 groups according to duration of employment(group 1 ; less than 9 years, group 2 ; 10-14 years, group 3 ; more than 15 years). The results of performance were analyzed considering of work duration, age, educational level, alcohol drinking, smoking and testing time as confounding factors. Benton visual retention test, pursuit aiming correct dot and sum of dot showed significant differences among the groups, and decreased with increasing work duration. It indicated that the mean scores of performance ability were lowering according to work duration. Besides, the tests that didn't show statistical significances but showed linear trends were depression-dejection, vigor, fatigue of POMS, slowest time of simple reaction time and digit span forward. Most of the neurobehavioral test items were correlated with age and educational level. After controlling of confounding factors-age and educational level, the results followed ; digit span backward was different significantly. Tension-anxiety, depression-dejection, anger-hostility of POMS, SD and slowest time of simple reaction time, Santa Ana dexterity test non-preferred hand, digit span forward, Benton visual retention test and pursuit aiming correct dot decreased with increasing of work duration. The correlation analysis was done in order to find out the relationship between subjective symptom and the scores of neurobehavioral core test battery. According to the results of analysis there were no items that had statistical significant relationship(p<0.05).

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.255-259
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• 2016

Background: Reliable and validated instruments are needed in order to study the quality of life in myeloma patients. This study aimed to translate and explore the psychometric properties of the European Organisation for Research and Treatment of Cancer (EORTC) myeloma module (QLQ-MY20) in Iranian patients. Materials and Methods: Two hundred and fifteen patients with multiple myeloma (MM) were recruited from Imam Khomeini Hospital, Tehran. A standard forward-backward translation procedure was implemented. Participating patients were asked to complete the EORTC QLQ-C30 and the QLQ-MY20 three times, at study entry, after two weeks, and again after three months. Data were tested for the range of measurement, internal consistency, test-retest reliability, known group comparison, responsiveness and factor structure. Results: Mean age of the patients was 60.7 years. No floor and ceiling effects were seen for the QLQ-MY20. Cronbach's ${\alpha}$ was greater than 0.80 for all three multi-item scales (ranging from 0.82 to 0.93). All four scales had test-retest reliability of 0.85 or greater. Results of the confirmatory factor analysis that the hypothesized 3-scale measurement model of the QLQ-MY20. Moreover, the Persian version for the QLQ-MY20 differentiated between subgroups of the patients in terms of beta-2 microglobulin, fracture and performance status. The responsiveness of the QLQ-MY20 to change over time was confirmed within 3 months. Conclusions: the results of our study indicate that our Iranian version of the QLQ-MY20 is a feasible, reliable and valid questionnaire for assessing the condition-specific quality of life of patients with MM.

• Composites Research
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• v.13 no.6
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• pp.47-54
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• 2000

One promising method for impact detection of composite structures is based on the use of piezopolymer thin fim (PVDf) sensor. In this paper, the relationship between the contact force and the signals of the attached strain gage and PVDF sensor to the composite plate subjected to low-velocity impact were derived. The relation for the open circuit and short circuit voltage of PVDF sensor was derived based on the equivalent circuit model of the piezoelectric sensor. The work was then extended to include experimental investigation into the use of short circuit voltage of PVDF sensor without using charge amplifier to detect low-velocity impact. The natural frequencies and damping ratio of the composite plate obtained from the vibration test were used to modify the analytical model and therefore the differences between measured and simulated signal of the modified analytical model in both forward and backward problem were considerably reduced. The reconstructed contact force and simulated sensor signals agreed well with the measured contact force, strain gage signal, and PVDF sensor singanl.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.827-832
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• 2013

In this study, curve responsiveness was assessed based on the lateral force and running safety was evaluated based on the wheel unloading ratio and derailment coefficient, which is the ratio of the wheel load and the lateral force. The evaluation of the curving performance and running safety of the new high-power electric locomotive showed that the derailment coefficient appeared higher when the wheel-set was set to the front of the train instead of being placed backward, and the maximum value of the derailment coefficient was recorded as 0.572 on the Gyeongbu line. Furthermore, the lateral force increased in curved sections, and it appeared to be proportional to the curve radius. Meanwhile, a maximum axis lateral force of 77.6 kN was recorded on the Taebaek line, and the wheel unloading ratio was 47.6% on the Yeongdong line. Finally, the running safety at the maximum speed as well as the through-curve performance of the curve radius satisfied the required standards.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.254-261
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• 2007

In this paper, we propose a blind equalization method for advanced terrestrial digital multimedia broadcasting (AT-DMB) systems which use hierarchical modulation. The AT-DMB system adopts hierarchical 16-ary quadrature amplitude modulation (16-QAM) to ensure backward-compatibly with the differential quadrature phase shift keying (DQPSK) signal of the legacy terrestrial digital multimedia broadcasting (T-DMB) systems and to support higher transmission rate. Due to the hierarchical modulation, the conventional T-DMB signal and the additional signal have different error rate at same signal to noise ratio (SNR). By weighting the decided symbols differently according to the reliability of the symbols, i.e., high priority symbol with low error rate and low priority symbol with high error rate, we can improve the channel estimation accuracy. In this paper, we analyze SNR loss by hierarchical modulation and confirm it through simulations. Moreover, through simulations, we verify that the proposed weighting method improve BER compared to the no-weighting method.

• Journal of KIISE:Information Networking
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• v.36 no.3
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• pp.231-242
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• 2009

The EPC-Discovery Service (EPC-DS) is a good representative of the RFID Track & Trace. But this mechanism has several problems. EPC-DS uses centralized server scheme which may arise bottle-neck state and that cannot provide detail trace information of a RFID object. In addition, a trace node requires direct access method to a RFID object or an element which has information of the RFID object for Track & Trace. In this paper, we propose a novel RFID Track & Trace mechanism which based on the SIP presence model and SIP event notification. This mechanism can provide detail trace information and monitoring function, and also can rid the bottle-neck section by combination of SIP methods instead of centralized element.