• 제목/요약/키워드: Internal variable

검색결과 806건 처리시간 0.027초

이동 고속데이타 서비스용 MAC계층 프로토콜의 성능연구 (A Study on the Performance of MAC Protocols for High-Speed Mobile Data Services)

  • 김태규;조동호
    • 한국통신학회논문지
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    • 제19권9호
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    • pp.1730-1738
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    • 1994
  • PCS(personal communication service)용으로 시존에 제안된 B-CDMA(broadband code division multiple access)기법은 전송 속도의 변동이 적은 저속의 음성호만을 고려하였기 때문에 고속의 가변 데이타 서비스를 제공하기에는 적합하지 않다. 한편, 최근에 제안된 Hybrid TDMA/CDMA(hybrid intra-cell TDMA/inter-cell CDMA)기법은 내부적으로 TDMA기법이 사용되므로 고속데이타 서비스를 용이하게 지원할 수 있지만 TDMA 전송특성 때문에 가변데이타 트래픽을 처리할 때에는 많은 비효율성을 내포한다. 본 논문에서는 이러한 단점들을 보완하기 위한 방안으로 Hybrid TDMA/CDMA 기법에 PRMA(packet reservation multiple access)에서와 유사한 예약기법을 추가로 적용한 Reservation TDMA/DCMA 기법을 제안하였다. 또한, 제안된 Reservation TDMA/CDMA기법의 성능을 컴퓨터 시뮬레이션을 통해 기존의 B-CDMA기법 및 Hybrid TDMA/CDMA 기법과 비교 분석하였다. 시뮬레이션 결과, 제안된 Reservation TDMA/CDMA 기법은 다양한 전송속도와 트래픽을 용이하게 지원할 수 있을 뿐만 아니라 설정된 각 호 내부에서의 전송속도 변화를 보다 효율적으로 이용할 수 있다는 측면에서 기존의 B-CDMA나 Hybrid TDMA/CDMA 기법보다 우수함을 알 수 있었다.

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항공서비스에 대한 고객만족이 거래지속의도에 미치는 영향에 있어서 성별의 역할 (The Influence of Customer Satisfaction on Customer Loyalty and the Moderating Effect of Gender)

  • 김문섭
    • 유통과학연구
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    • 제14권10호
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    • pp.73-79
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    • 2016
  • Purpose - Customer satisfaction has been considered important as a way to retain current customers. Specifically, the retention of current customers through customer satisfaction has been considered important in an industry where competition between companies is fierce. Major Korean airlines have confronted fierce competition with the growth of low cost carriers (LCCs). In order to survive, these airlines need to retain their customers. This research aims to investigate the relationships between customer satisfaction and the customer intention to remain loyal. Moreover, this study examines how the influence of customer satisfaction on customer loyalty is moderated by gender. Research design, data, and methodology - A regression model is developed in which customer satisfaction, gender, and an interaction of satisfaction and gender are predictors and the customer's intention to remain loyal is a dependent variable. To analyze this research model, data were collected from 402 university students taking a marketing class in universities in Seoul, Chung-Cheong province, and Kangwon province. After eliminating data from students who had never flown and data with missing values, a final sample of 201 was analyzed. The hypotheses were tested using SPSS 21.0. Internal reliability was supported by the results of Cronbach's α. Multiple regression was performed. Results - Empirical results showed that customer satisfaction toward the airline's service had a positive influence on the customer intention to remain loyal to the airlines. Moreover, this influence was moderated by gender. More specifically, a male customer's intention to remain loyal was more determined by his satisfaction toward airline service than a female customer's. Conclusions - This research contributes to the aviation service marketing literature by showing how customer satisfaction influences customer intention to remain loyal and how this influence is moderated by gender. More specifically, male customer loyalty is more determined by airline service satisfaction than female customers. These results have manager implications for major Korean airlines in terms of customer satisfaction and gender as ways to enhance customer retention.

거골 경부 골절의 합병증 (The Complication of the Talar Neck Fracture)

  • 성병년;박완수;이승기;박찬지;김동원
    • 대한족부족관절학회지
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    • 제7권1호
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    • pp.119-125
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    • 2003
  • Purpose: The purpose of this study fracture. Materials and Methods: The clinical and radiological analysis were performed on 19 cases of the talus neck fractures who had been treated with conservative treatment or variable methods of operative treatment. Each cases followed up more than 1 year and 6 months from May 1989 to June 2001. The clinical results were analyzed according to the age, cause of injury, fracture type of Hawkins classification, associated soft tissue injury, method of treatments, complications, and Hawkins scoring system. Results: According to Hawkins classification, type I was 6 cases(32%), type II was 5 cases(26%), typeIII was 7 cases(37%), and typeIV was 1 case(5%). In all cases, complete bony union was obtained. According to the Hawkins scoring system, 8 cases(42%) were excellent and good. Avascular necrosis was 4 cases(25%). Traumatic arthritis was 10 cases which were occurred in type II, III and IV. An ankle fusion was 1 case. Conclusion: In talar neck fractures, non-displaced fracture treated by the cast immobilization and displaced fracture treated by early open reduction and internal fixation were expected good results. The complications were 77% of traumatic arthritis and 31% of avascular necrosis in type II, III and IV. We should preoperatively explain to the patient for high complication rates of traumatic osteoarthritis and avascular necrosis in the talus neck fractures.

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인천광역시 의원기반 건강포인트제도가 고혈압·당뇨병 환자의 지속치료에 미치는 영향 (The Effect of a Clinic Based Incentive Program on Medication Adherence among Patients with Hypertension or Diabetes Mellitus in Incheon)

  • 정원;임준;오대규;임정수;고광필;박이병
    • 보건행정학회지
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    • 제23권4호
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    • pp.427-433
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    • 2013
  • Background: This study was conducted to evaluate the factors affecting adherence in patients with hypertension and type 2 diabetes mellitus before and after a clinic based patient incentive program in Incheon. Methods: An observational follow-up study was done for 28,355 patients in one registered group and 245,598 patients in a non-registered group from March 16th 2009 to December 31th 2010 in Incheon. The registration, mandatory laboratory tests and number of clinic visits were collected by merging the Incheon Chronic Disease Management System data and the National Health Insurance Corporation (NHIC) data. As a measure of patient adherence, we used a variable of prescription days from the NHIC and defined above 80% of average prescription days as an appropriate patient adherence. Repeated measures analysis of variance and logistic regression were used to analyze the differences in patient adherence and factors affecting adherence. Results: The changes in prescription days for the registered group are larger than for the non-registered group. In the logistic regression model, including the variables with sex, age, income status and number of clinic visits, the registered group exhibited a higher Odds ratio in the patient adherence. Conclusion: This study revealed the association between registration and appropriate patient adherence in patients with hypertension or type 2 diabetes mellitus.

Antimicrobial Effects of a Hexapetide KCM21 against Pseudomonas syringae pv. tomato DC3000 and Clavibacter michiganensis subsp. michiganensis

  • Choi, Jeahyuk;Baek, Kwang-Hyun;Moon, Eunpyo
    • The Plant Pathology Journal
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    • 제30권3호
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    • pp.245-253
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    • 2014
  • Antimicrobial peptides (AMPs) are small but effective cationic peptides with variable length. In previous study, four hexapeptides were identified that showed antimicrobial activities against various phytopathogenic bacteria. KCM21, the most effective antimicrobial peptide, was selected for further analysis to understand its modes of action by monitoring inhibitory effects of various cations, time-dependent antimicrobial kinetics, and observing cell disruption by electron microscopy. The effects of KCM21 on Gram-negative strain, Pseudomonas syringae pv. tomato DC3000 and Gram-positive strain, Clavibacter michiganensis subsp. michiganensis were compared. Treatment with divalent cations such as $Ca^{2+}$ and $Mg^{2+}$ inhibited the bactericidal activities of KCM21 significantly against P. syringae pv. tomato DC3000. The bactericidal kinetic study showed that KCM21 killed both bacteria rapidly and the process was faster against C. michiganensis subsp. michiganensis. The electron microscopic analysis revealed that KCM21 induced the formation of micelles and blebs on the surface of P. syringae pv. tomato DC3000 cells, while it caused cell rupture against C. michiganensis subsp. michiganensis cells. The outer membrane alteration and higher sensitivity to $Ca^{2+}$ suggest that KCM21 interact with the outer membrane of P. syringae pv. tomato DC3000 cells during the process of killing, but not with C. michiganensis subsp. michiganensis cells that lack outer membrane. Considering that both strains had similar sensitivity to KCM21 in LB medium, outer membrane could not be the main target of KCM21, instead common compartments such as cytoplasmic membrane or internal macromolecules might be a possible target(s) of KCM21.

외다이아프램 응력경로에 따른 용접조립 각형기둥-보 접합부의 내진성능 평가 (Seismic Evaluation of Welded-formed square Column-Beam Connection for External Diaphragm Stress path)

  • 김선희;염경수;최성모
    • 한국강구조학회 논문집
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    • 제26권4호
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    • pp.311-322
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    • 2014
  • 콘크리트 충전강관 기둥에 모멘트 접합부를 만들기 위해서는 추가적인 다이아프램 설치가 필요하다. 그 중 내측 다이아프램과 관통 다이아프램을 용접하기 위해서는 기둥강관에 특수한 용접기술이 필요하다. 하지만 이런 기술은 제작업체의 특수장비 보유에 따라서 제작성 저하와 생산단가 상승 유도 등의 문제를 갖고 있다. 따라서 본 연구에서는 외다이아프램을 갖는 실대형 기둥-보 접합부를 제작하였고, 반복가력 실험을 수행하였다. 다이아프램의 용접 유무와 콘크리트 충전 여부, 형상에 따른 총 6개의 T자형 접합부 실험을 통해 내진성능을 평가하였다. 또한 외다이아프램 내력식에 대한 분석이 이뤄졌다. 본 실험에서 나온 결과를 인장내력식의 적절성을 검토 하였다.

Geographic Genetic Contour of A Leaf Beetle, Chrysolina aurichalcea (Coleoptera: Chysomelidae), on the Basis of Mitochondrial COI Gene and Nuclear ITS2 Sequences

  • Park, Joong-Won;Park, Sun-Young;Wang, Ah-Rha;Kim, Min-Jee;Park, Hae-Chul;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • 제23권1호
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    • pp.155-166
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    • 2011
  • The leaf beetle, $Chrysolina$ $aurichalcea$ (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) of the species collected from seven Korean localities. A total of 17 haplotypes (CACOI01~CACOI17), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 16 sequence types (ITS2CA01~ITS2CA16), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in COI gene sequence. Phylogenetically, the COI gene provided two haplotype groups with a high nodal support (${\geq}87%$), whereas ITS2 provided only one sequence type group with a high nodal support (${\geq}92%$). The result of COI gene sequence may suggest the presence of historical biogeographic barriers that bolstered genetic subdivision in the species. Different grouping pattern between COI gene and ITS2 sequences were interpreted in terms of recent dispersal, reflected in the ITS2 sequence. Finding of unique haplotypes and sequence types only from Beakryeng-Islet population was interpreted as an intact remnant of ancient polymorphism. As more samples are analyzed using further hyper-variable marker, further fruitful inference on the geographic contour of the species might be available.

급속도로 진행된 전이성 척추종양에 의한 흉통 (Chest Pain due to Rapidly Developed Metastatic Spinal Tumor - A case report -)

  • 이준학;김형태;문철신;허현언;권영은
    • Journal of Hospice and Palliative Care
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    • 제12권2호
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    • pp.88-94
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    • 2009
  • 흉통은 외래 및 응급실에서 볼 수 있는 흔한 증상으로 그 원인 또한 다양하다. 또한 흉통의 원인에 따라 치료와 예후가 다르기 때문에 흉통의 원인을 정확히 진단하는 것은 무엇보다 중요하다. 흉통을 호소하는 환자들 중 대부분은 개인병원, 종합병원의 내과, 흉부외과 등을 거쳐 기본적인 검사를 실시하고 특별한 이상이 없다고 진단 받고 통증클리닉으로 보내지는 경우가 많지만, 최근에 다른 과를 거치지 않고 직접 통증클리닉을 찾는 환자가 많아짐을 고려할 때 정확한 진단이 필수적이다 하겠다. 본원에 흉통을 주소로 입원치료 중에 있던 환자에서 전이성 척추종양에 의해 급속도로 진행된 척추파괴 및 척수압박 증상을 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

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하수처리장 소수력 수차 블레이드의 압력변화 특성 분석을 통한 구조안전성 평가 (Structural Safety Evaluation by Analysis of Pressure Variation Characteristics of Small Hydro Power Hydraulic Turbine Blades in Sewage Treatment Plant)

  • 박유신;김기중;윤병돈
    • 한국구조물진단유지관리공학회 논문집
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    • 제21권6호
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    • pp.126-131
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    • 2017
  • 저유속 조건에서 소수력 에너지 생산 효율 증진을 위한 항력식 수직축 수차를 개발하기 위하여 전산 유체 동역학(CFD) 기법을 이용하여 수치해석을 수행하였다. 1.0~3.0 m/s의 유속 조건에서 수차 블레이드의 타공 유무에 따른 블레이드 압력 변화와 내부유동을 분석하였다. 수치해석 결과, 타공이 있는 경우 유속에 따라 수차 블레이드의 압력 및 유체 속도가 영향을 크게 받는 것으로 나타난 반면에, 타공이 없는 경우에는 유속에 따른 수차 블레이드의 압력 및 유체 속도의 영향이 상대적으로 감소하는 것으로 나타났다. 또한, 타공이 포함되지 않은 수차 블레이드에 비교하여 타공이 포함된 수차 블레이드 표면에서 압력 분포와 유체의 속도가 고르게 나타났으며, 따라서 수차 블레이드에 타공을 형성하는 것이 구조안전성 측면에서 도움이 될 것으로 판단된다.

허프만 복호화를 위한 균형이진 검색 트리 (A Balanced Binary Search Tree for Huffman Decoding)

  • 김혜란;정여진;임창훈;임혜숙
    • 한국통신학회논문지
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    • 제30권5C호
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    • pp.382-390
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    • 2005
  • 허프만 코드는 영상이나 비디오 전송뿐만 아니라 여러 분야에서 광범위하게 사용되고 있는 데이터 압축 알고리즘으로서, 실시간 데이터의 양이 증가함에 따라 효율적인 디코딩 알고리즘에 관한 많은 연구가 진행되고 있다. 본 논문에서는 호프만 디코딩을 위해 균형 트리를 형성하여 효율적인 이진 검색을 수행하는 구조를 제안하고 타 구조와의 성능을 비교하였다. 제안하는 구조는 길이가 다른 코드워드 간의 크기 비교를 가능하게 하는 정의를 사용하여 비어있는 내부 노드를 포함하지 않는 완전 균형 트리를 구성하므로, 디코딩 테이블을 위해 필요로 하는 메모리의 크기에 있어 매우 우수한 구조이다. 실제 영상 데이터를 사용하여 실험한 결과, 256개의 심볼 set에 대해 제안하는 구조는 매우 적은 수의 테이블 엔트리를 요구하며, 디코딩 성능은 최소 1번, 최대 5번, 평균 2.41번의 메모리 접근을 소요함을 보았다.