• 제목/요약/키워드: Three-port

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단일 페라이트 공진기를 이용한 4단자 스트립라인 서큘레이터 (A four-port stripline circulator using a single ferrite disk)

  • 김혜진;남민희;이재현
    • 한국위성정보통신학회논문지
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    • 제4권2호
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    • pp.52-56
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    • 2009
  • 본 논문에서는 그린 함수(Green's function) 방법을 이용하여 하나의 페라이트 디스크를 사용하는 4 단자 스트립라인 서큘레이터 설계 방법을 제안한다. 통신 시스템 설계의 유연성을 높일 수 있는 4 단자 서큘레이터는 이제까지 2개의 3 단자 서큘레이터를 연결하여 사용하고 있다. 이를 하나의 페라이트 디스크를 사용하는 4 단자 서큘레이터로 대체하면 무게와 부피를 감소시킬 수 있어서 위성용으로 장점을 갖는다.

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A Study on the Profitability of Private Finance Initiative Ports Companies and the Use of Old Ports Rehabilitate-Project

  • Yang, HuckJun
    • 한국항해항만학회지
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    • 제44권5호
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    • pp.430-437
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    • 2020
  • This paper analyzes the profitability of the Private Finance Initiative(PFI) ports and proposes the application plans of the R-project(Rehabilitate project) for old ports to attract and activate private investment in the port industry. The R-project of old ports can reduce the government's financial budget and provide improved facilities for users more quickly than the public sector comparator. Before suggesting the R-project for old ports, the profitability of the currently operating 11 companies of the PFI ports are analyzed using the four ratios of profitability, and the results show that all the companies indicate low profitability, except for the top three companies. To apply the R-project, the three types of R-project ports are categorized as maintaining the function of the port, changing the function of the port, and mixing the function of the port. Additionally, three obstacles and improvement measures are suggested; attracting private business, legal issues, and administrative procedures. This study is conducive to the policy making for the port renewal and the activating PFI for the port industry.

항만물류 서비스품질 차원이 고객만족도에 미치는 영향 - 인천항 컨테이너 터미널을 중심으로 - (The Relative Effects of Three Dimensions of Port Logistics Service Quality on Customer Satisfaction)

  • 김병일
    • 한국항만경제학회지
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    • 제22권1호
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    • pp.125-149
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    • 2006
  • The main purpose of this study is to develop new measurement device of the quality of terminal service, applying the existing research output of service marketing to the specific industrial aspect of container terminal. Especially we tried to help marketing managers present the points of effective marketing strategy with each dimension of service quality. To achieve this aim, we defined the service quality demensions of container port as the following three ones; the internal, the external, and the interactive qualities. The applied measuring instruments could be divided into three dimensions by carrying out factor analysis. Additionally, by analyzing the relative effects of the three dimensions of service quality on customer satisfaction, we found that the relative importance are as follows; interaction quality>internal quality> external quality. We confirmed that the three dimensions of service quality could affect customer loyalty and information, through customer satisfaction.

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Three-Port Laparoscopic Exploration is not Sufficient for Patients with T4 Gastric Cancer

  • Huang, Hua;Jin, Jie-Jie;Long, Zi-Wen;Wang, Wei;Cai, Hong;Liu, Xiao-Wen;Yu, Hong-Mei;Zhang, Li-Wen;Wang, Ya-Nong
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권19호
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    • pp.8221-8224
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    • 2014
  • Gastric cancer continues to be a leading cause of cancer death. The majority of patients with gastric adenocarcinoma in China present with advanced disease. Ruling out unresectable cancers from an unnecessary "open" exploration is very important. The aim of this study was to assess the value of five-port anatomical laparoscopic exploration in T4 gastric cancer in comparison with three-port laparoscopic exploration and laparotomy exploration. We conducted a retrospective study on 126 patients with T4 stage scheduled for D2 curative gastrectomy based on computed tomography (CT) staging at Department of Gastric Cancer and Soft Tissue Sarcoma, Fudan University Shanghai Cancer Center, from Apr. 2011 to Apr. 2013. Laparotomy exploration (Group I), three-port laparoscopic exploration (Group II) or five-port anatomical laparoscopic exploration (Group III) were performed prior to radical gastrectomy. Accuracy rate for feasibility of D2 curative gastrectomy in laparotomy exploration and five-port anatomical laparoscopic exploration groups was higher than that in the three-port laparoscopic exploration group. Five-port anatomical laparoscopic exploration group had the highest accuracy resection rate (Group I vs Group II vs Group III,92.6% vs78.6% vs 97.7%; p<0.05) and shorter length of hospitalization (Group I vs Group II vs Group III, $9.58{\pm}4.17$ vs $6.13{\pm}2.85$ vs $5.00{\pm}1.81$; p<0.001). Three-port laparoscopic exploration has low accuracy rate for assessing feasibility of D2 curative gastrectomy and five-port anatomical laparoscopic exploration should be performed on patients with T4 gastric cancer.

리버스 엔지니어링을 통한 디젤엔진 흡기포트의 성능 비교 (Diesel Engine Intake Port Analysis Using Reverse-engineering Technique)

  • 김창수;박성영
    • 한국자동차공학회논문집
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    • 제23권5호
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    • pp.502-507
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    • 2015
  • In this paper, we built a three-dimensional model by applying reverse engineering techniques on targeting the intake port of 2900cc class diesel engine before that three-dimensional design technique is applied. The performance of the intake port is predicted and analysed using the computational flow analysis. Flow Coefficient and Swirl Ratio have been analyzed for two intake port models. One is the intake port for the diesel engine with plunger-type fuel system, and the other is for the diesel engine with CRDI fuel system. Computational result shows that the Flow Coefficient of the intake port with CRDI fuel system is increased upto 10 percentage compared with that with plunger-type. Also, the intake port with plunger-type has high Swirl Ratio at high valve lift, and the intake port with CRDI fuel system has high Swirl Ratio at relatively low valve lift. It is believed that because of high performance of the fuel injector, the intake port with CRDI fuel system is designed for more air amount and not much swirl flow at high valve lift. However, high swirl flow is required at low valve lift for initial fuel and air mixing. The result of this study may be useful for the re-manufacturing industry of automotive parts.

Study on the Relationship and Validity of the Management Evaluation Factors in Public Firms With a Focus on the Port Authorities

  • Lee, Sung-Yhun;Ahn, Ki-Myung
    • 한국항해항만학회지
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    • 제43권6호
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    • pp.450-461
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    • 2019
  • According to the results of the management evaluation of the nation's public firms over the past seven years, the rating of the port corporation is generally insufficient. According to the results of the seven-year study 2011-2017, the average debt ratio of the port corporation was 34.5%, two to three times lower than that of the general public company, the operating profit ratio of sales was three times higher, and the value added per person was 1.6-1.9 times better. However, the aggregate score and grade were generally low, with 4.1% of the total number of employees of the general public corporation, 10% of the average total assets, and 1% of the average sales volume. The distributed analysis results and panel return analysis results show that the size significantly impacts the overall score and grade. Additionally, major business standards such as port volume, not controlled by the port corporation, appear to have a decisive influence on the low grade of the port corporation. Thus, it appears that improvement and supplementation of key business indicators of port construction are urgently needed in the management evaluation system, which can be properly controlled.

Field investigations on port non-tranquility caused by infra-gravity water waves

  • Najafi-Jilani, A.;Rahimi-Maleki, D.
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제2권1호
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    • pp.34-38
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    • 2010
  • Field investigations have been carried out in two 60-day stages on the surf beat low frequency waves in Anzali port, one of the main commercial ports in Iran, located in southwest coast of the Caspian Sea. The characteristics of significant water waves were measured at three metering stations in the sea, one at the entrance of the port and three in the basin. The measured data were inspected to investigate the surf beat negative effects on the tranquility of the port. Using field measurements and complementary numerical modeling, the response of the basin to the infra-gravity long waves was inspected for a range of wave frequencies. It was concluded that the water surface fluctuations in the port is strongly related to the incident wave period. The long waves with periods of about 45s were recognized as the worst cases for water surfaceperturbation in the port. For wave periods higher than the mentioned range, the order of fluctuation was generally low.

Calibration of frequency propagation channel sounder based on five-port reflectometer

  • Yem Van;Braga Judson;Huyart B;Begaud X;de Sousa F.R;Huyen Nguyen Bich
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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    • pp.23-26
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    • 2004
  • Five-port reflectometer which consists of a ring with 5 arms (two inputs, three outputs) and three RF power detectors has been used as a vector network analyser, a demodulator in the homodyne receiver as well as in Phase Looked Loop (PLL) and so on. Calibration of five-port reflectometer is an important task. In this paper, we present a calibration method of five-port for a propagation channel sounder. The method is based on measurement of the phase differences between the three voltages at the five-port's outputs in order to determine the ratio of two input incident waves. The frequency channel sounder based on five-port is calibrated for each frequency from 2.2 GHz to 2.6 GHz with 1 MHz step. This method can also determine the absolute delays of each propagation path in the propagation channel. The calibration method is validated using measurement data.

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중복배제의 관점에서 본 우리나라 항만관리에 관한 연구 - 항만 관련법률을 중심으로 - (A Study on the Korean Port Management in a viewpoint of Overlap Elimination - Focused on the Related Port Law -)

  • 최근배
    • 무역상무연구
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    • 제39권
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    • pp.281-310
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    • 2008
  • An understanding of importance of port has increased according to the in and out environment changes surrounding port. And the jurisdiction of physical distribution including port logistics integrated to Ministry of Land, Transport and Maritime Affairs. It is a good time for review the related port law once more. Present related port law has no problems itself. But because there are many laws about port, so overlap is shown in many aspects. According to this viewpoint, this study has focused to reduce the overlap in the contents of the laws and propose the improvement methods. So as to achieve this goal, I divided study fields into three aspects. The first is the subject of port management and second is the object of port management, the third is contents of port management. And also improvement plan provided in three aspects. Improvement plan is as follows. Firstly, the diversity of management subject is reduced considerably due to the integration of government organization but the problem which what laws among the various laws would adopt to same object is still remained. So it is necessary to make into one or two laws. Secondly, in the case of object of port management, it is essential to cover the port, port facilities and port hinterland with one comprehensive law. Therefore it is important to adjust the related clauses in various laws. Thirdly, in connection with the contents of port management, port development plan or other related port business and etc. described in various laws have to cordinated. At the same time, it is desirable that the similar terminology used in various laws would be unified.

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Comparative Studies on Ports Management System in Northeast Countries

  • Kim, Jin-Hwan
    • 유통과학연구
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    • 제14권1호
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    • pp.29-38
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    • 2016
  • Purpose - The purpose of paper is to review and look into the process of port development of each country, and compare with their system of port management. Research design, data and methodology - The methods to be taken is to examine a process of port development in terms of historic and regulated point of views, and each country's port is compared with various port models. Results - China has evolved of port governance into 3 stages, which has lead to almost liberalized port management system in process of privatization slogan. Japan has three stages of port development, and key commitments have been done by local government, rather than national one. Korea has also several stages of port reforms, and national government has been deeply involved in port industry, as well as regional government and port authority in certain areas. Conclusions - whatever port management system each countries has taken, it eventually aims to port productivity in country's port. To adopt most proper port management system may be answer for country to cope with environmental changes around port industry.