• Title/Summary/Keyword: Segmental

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Overlapped Segmental Clipping for the PAPR Reduction of the OFDM-OQAM system

  • Wang, Jianping;Yan, Jing;He, Zhen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.8
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    • pp.2783-2795
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    • 2014
  • Orthogonal frequency division multiplexing with offset quadrature amplitude modulation (OFDM-OQAM) technique has drawn significant interests in recent years. However, most of the existing OFDM peak-to-average ratio (PAPR) reduction schemes cannot be used in the OFDM-OQAM system directly. In this paper, a modified scheme called overlapped segmental clipping (OS-clipping) is proposed to deal with the high PAPR problem specifically in the OFDM-OQAM system. For the proposed OS-clipping scheme, the input signals are divided into a number of overlapped segments and then the clipping operation is processed on each segment. Simulation results show that the modified scheme used in the OFDM-OQAM system can provide better performance than conventional clipping scheme directly used in the OFDM-OQAM system, and even outperforms conventional clipping scheme applied in the OFDM system.

Experimental Study of Anchor Zone of Externally Prestressed Segmental Bridge (현장 실험을 통한 상판분절 P.C 교량의 정착부 응력 분석)

  • 이성우;배두병;지기환;정남석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.10a
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    • pp.87-94
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    • 1994
  • During the construction of externally prestressed 7-span continuous segmental bridge, cracks beyond permissible limit were found at anchor zone of expansion joint segment. To eliminate this problem, tension side of diaphragm was prestressed by post-tensioning bars in vertical and horizontal direction. To investigate this remedy is acceptable, stresses of reinforcing bars and concrete surface were measured for the real structure in the field. The measurement was performed through each step of prestressing sequence during construction. Also to investigage stresses induced by live load, static load test was performed and the results was analyzed. In this paper it will be presented the procedure and results for this experimental study along with comparison with analytical study.

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Performance Evaluation and Comparison of Conventional 12/8 and Novel 6/5 Switched Reluctance Motors (기존 12/8 및 새로운 6/5 SRM의 성능분석 및 비교)

  • Xu, Zhenyao;Lee, Dong-Hee;Ahn, Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2016.07a
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    • pp.517-518
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    • 2016
  • In this paper, a novel 6/5 switched reluctance motor (SRM) with segmental rotor is proposed for vehicle cooling fan application. Unlike conventional SRMs, the proposed motor adopts hybrid stator poles and segmental rotor structures, thereby making the motor operate in short flux paths and parts of the flux paths magnetically isolated between the phases. Therefore, compared with conventional SRMs, the proposed structure could improve the output torque density and reduce the core loss, thereby improving the electric utilization of the motor. To verify the proposed structure, the performance of the proposed structure is evaluated. Meanwhile, a conventional 12/8 SRM which has been used for vehicle cooling fan application is also evaluated. Finally, the effectiveness of the proposed SRM is demonstrated by the simulation and experimental results.

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Effects of Halothane on Dimyristoylphosphatidylcholine Lipid Bilayer Structure: A Molecular Dynamics Simulation Study

  • Oh, Kwang-Jin;Klein, Michael L.
    • Bulletin of the Korean Chemical Society
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    • v.30 no.9
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    • pp.2087-2092
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    • 2009
  • We performed molecular dynamics simulations on dimyristoylphosphatidylcholine lipid bilayer with 50 mol% halothane. The structural properties, electron density profile, segmental order parameter of acyl chains, headgroup orientation distribution, water dipole orientation distribution, have been examined. Overall the effects of the halothane molecules on structural properties of DMPC lipid bilayer were found to be small. The electron density profiles, the segmental order parameter, the headgroup orientation, the water dipole orientation were not affected significantly by the halothane molecules. Pressure tensor calculations shows that the lateral pressure increases at the hydrocarbon tail region and the headgroup region, and decreases at the water-headgroup interfacial region.

Parallel sound change between segmental and suprasegmental properties: An individual level observation

  • Lee, Hyunjung
    • Phonetics and Speech Sciences
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    • v.8 no.4
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    • pp.23-29
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    • 2016
  • The present study tested if individual speakers showing great sound change in segments (i.e., vowels and fricatives) also had innovative changing patterns in suprasegmental properties (i.e., lexical pitch accents) in Kyungsang Korean. The acoustic analysis at a group level first confirmed the presence of group level differences in distinguishing /ɨ-ʌ/ and /s-s'/ both of which had different phonemic distinction from Seoul Korean. Younger speakers had more innovative segmental change than older speakers, and even within the younger generation, female speakers produced more innovative phonetic variants than male speakers. Regarding the individual observation within the younger group, the younger speakers with large acoustic distinction in vowels and fricatives also showed acoustically less distinct accent patterns, indicating the innovative sound change pattern consistent across segment and suprasegmental properties. The group and individual observations suggested that linguistic innovators introduced new phonetic variants with consistent degree of changing pattern between segment and suprasegmental properties.

A Study on the Neurotoxic Effects of Tellurium on Murine Nervous System (랫드의 신경조직에 미치는 Tellurium의 독성에 관한 연구)

  • 김기석;정문호
    • Journal of Environmental Health Sciences
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    • v.24 no.3
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    • pp.35-40
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    • 1998
  • This study was conducted to examine the pathological changes of rat peripheral nervous system during exposure to tellurium known to be a demyelinating agent by using teasing nerve fiber method and quantitative light microscopic analysis by image analyzer. The pellet containing 1.2% of tellurium were fed for 3, 5, 7, 9, 13 days to male wistar rats (21 days old) and then neurologic symptom and the feature of nerve fiber myelination were studied. From this study, following results were obtained. In 3 days treated group, it showed various neurologic symptom and teased nerve fiber showed slight irregularity of the myeline sheath. In 5 days and 7 days treated groups, it showed the segmental demyetination in larger size fiber and widening of nodes of ranvier. In 9 days and 13 days treated groups, the remyelinated fibers were observed and it was generally small in size. We consequently suggest that teasing nerve fiber method and quantitative analysis of nerve fiber were useful pathologic screening method of neurotoxicity of the peripheral nervous system.

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Pulmonary Aspergillosis - Pulmonary Aspergillosis - (폐 Aspergillosis -6예 보고-)

  • 김치경
    • Journal of Chest Surgery
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    • v.12 no.1
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    • pp.1-8
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    • 1979
  • Pulmonary aspergillosis is being recognized with increasing frequency in recent years and the-rising incidence of this infection parallels certain medical advances in antibiotics, chemotherapeutic and immunosuppressive therapy. The cavities of lungs resulting from tuberculosis, histoplasmosis or neoplasm are apt, to be infected by one of the species of the genus Aspergillus and eventually mycetomas are formed within the cavities. Authors have experienced 6 cases of pulmonary aspergillosis forming mycetoma in Dept. of Thoracic Surgery, Catholic Medical Center from Aug. 1976 to Feb. 1979. Hemoptysis or blood tinged sputum, the predominant symptom, occurred in all cases. All patients underwent pulmonary resection, 1 pneumonectomy, 3 lobectomies, 1 lobectomy with segmental resection and 1 segmental resection and survived well without death or complication. Primary aspergillosis was in 2 cases and underlying diseases were present in 4 cases: 3 pulmonary tuberculosis, 1 bronchiectasis. The common diagnostic study of intracavitary mycetoma was the posterioanterior chest roentgenogram; in cavities suspected of being diseased or in doubtful cases, tomography was most available to find fungus ball with air-meniscus shadow.

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Surgical Observation of Bronchiectasis (기관지확장증의 외과적 치료)

  • Lee, Dong-Jun;Chung, Chan-Yong
    • Journal of Chest Surgery
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    • v.11 no.3
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    • pp.260-264
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    • 1978
  • Sixty-one bronchiectatic patients were reviewed who were treated by surgical intervention in the Department of Thoracic and Cardiovascular Surgery, Chonnam University Hospital during the recent 14 years from January of 1965 to August of 1978. 1. Various pulmonary resection was performed; lobectomy was 55.5%, lobectomy and segmental resection 20.6%, bilobectomy 13.1%, lobectomy, segmental resection and thoracoplasty 4.9% and pneumonectomy was 3. 2%. 2. The most common associated disease was pulmonary Tbc, its frequency was 47.5% and next was chronic bronchitis [31%]. 3. The postoperative complication was observed in 19.6% [12 cases] and the most common was wound infection. 4. The possibility of recurrence was relatively high in the cases of residual lesion and it needs more intensive medical care. 5. The surgical result was satisfactory in 86.9% (53 cases), slight improvement in 4.9% (3 cases) and the mortality rate was 1.6% (1 case).

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Completing the Seohae Grand Bridge Construction Supervision (서해대교 감리를 마치며)

  • 전준수
    • Journal of the Korean Professional Engineers Association
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    • v.34 no.1
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    • pp.23-26
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    • 2001
  • Seohae Grand Bridge is a part of the new West Coast Highway(353km) under construction, which connects Inchon and Mokpo. It is the longest bridge in Korea (7.31 km), and has 97 spans of 60m each precast segmental approach bridges, 2 main spans of 165m each free cantilever segmental bridge(500m), and 1 stay cable bridge of 990m In total length. During the seven year long construction period, many new construction technologies and methods were utilized for the first time in Korea, and gave invaluable opportunities to experience and master these in completing the project on time with safety and precision. I am proud of being a member of this project, and wish to express deep appreciations to those who participated in the project.

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