• 대한토목학회논문집
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• 제35권6호
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• pp.1309-1320
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• 2015

본 연구는 시내버스 서비스 수준을 의미하는 노선별 차량 운행대수의 영향을 미치는 운행여건과 상관성 분석에 관한 연구이다. 분석방법은 회귀분석방법을 적용하였으며, 분석대상은 울산시 2013년 기준 98개 노선으로 한정하였다. 상관성분석을 위한 모형 도출을 위해 먼저 상관분석을 실시하여 종속변수인 운행대수와 독립변수인 운행거리, 운송수입금, 운송원가간의 관계를 분석한 결과, 아주 높은 유의수분에서 상관성이 있는 것으로 확인되었다. 회귀분석은 모형을 3가지 유형으로 구분하여 실시하였으며, 그 결과는 다음과 같다. 첫 번째 울산시 98개 버스노선 전체를 대상으로 도출한 모형은 Y(운행대수)=$-4.532+0.00002877*X_1$(운송수입금)인데, 이 의미는 운행대수 1대 증차를 위한 필요조건은 1일 승객 수가 140명 정도 증가하여야 시행할 수 있다는 점을 알려준다. 두 번째는 일반형, 좌석형, 중형으로 구분되는 버스 운행형태별 모형은 일반형의 경우 Y(운행대수)=$-10.954+0.00004283*X_1$(운송수입금), 일반형 시내버스를 1대 증차하기 위해서는 1일 승객 수가 약 153명 정도 증가되어야 시행할 수 있음을 보여주며, 중형의 모형은 Y(운행대수)=$-0.859+0.00001438*X_1$(운송수입금)인데, 이 의미는 1일 승객 수가 약 52명 정도 증가되어야 시행 가능함을 보여준다. 세 번째는 버스노선 운행체계별 모형 분석의 경우, 공동배차제의 경우 Y(운송대수)=$-4.786+0.00003028*X_1$(운송수입금)인데, 이 의미는 운행대수 1대 증차를 위한 필요조건은 1일 승객 수가 약 140명 정도 증가해야만 시행할 수 있으며, 개별노선제의 경우 Y(운행대수)=$-2.339+0.00002030*X_1$(운송수입금)인데, 이 의미는 운행대수 1대 증차를 위한 필요조건은 1일 승객수가 약 140명 정도 증가되어야 시행할 수 있음을 보여준다. 따라서 버스노선 운영체계별로 모형을 도출하여 운영체계가 시내버스 노선별 차량 운행대수에 미치는 영향을 분석한 결과, 두 가지 운영체계 모두 차량 증차를 위한 추진할 경우, 1일 승객 수가 140명 정도는 확보되어야 한다는 공통적인 결론에 도달되었으며, 노선운영체계 특성에 따른 노선별 차량 운영대수 차이는 거의 없는 것으로 분석되었다.

• 한국항행학회논문지
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• 제26권6호
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• pp.434-440
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• 2022

ICAO (international civil aviation organization)에서는 전략적인 의사결정과 항공교통관리 평가를 위해 세계항행계획인 GANP (global air navigation plan) 수행을 체약국에게 권고하였다. 본 연구에서는 항공교통관리 평가를 위해 제시된 KPI (key performance indicator) 05 실제 항로 연장에서 항로거리를 구하는 새로운 방법을 제안하였다. 이를 위해 한 달간의 항적 데이터를 수집하고 ICAO에서 제시한 방법과 본 저자가 제시하는 방법으로 각각 항로거리를 산출하였다. ICAO 방법은 반경 40 NM 원형에 대한 원의 방정식과 항적 데이터 내 원에 근접한 내·외부 지점에 대한 직선의 방정식을 통하여 교점을 추정하여야 하고, 네 가지의 비행거리를 계산하여 항로거리를 산출한다. 본 연구에서 제시한 방법은 교점을 추정하지 않고 두 가지의 비행거리를 계산하여 항로거리를 산출한다. 두 방법의 오차를 확인하기 위해 회귀모형 성능평가지표인 RMSE (root mean square error)와 결정계수 R² 를 사용하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.234-236
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• 2007

Even though the existing train route controlling method, using track circuits, ensures the sufficient number of operation, it still has problems such as discordance between train numbers which was planned for operating and train numbers being operated on the track, and allowing only one train entering for one route. To solve those problems, we study and develop the Smart train route controlling system which uses the real-time informations of train positions. This system enables improve the coefficient of utilization in a certain train route controlling section, and the safety level of train route controlling, but we should ensure satisfying reliability of data about tracks operated by trains. In addition, there is a need to protect accidents caused by erroneous information of train position, by reflecting changes of tracks, for example maintenance, improvement, expansion of tracks. In this paper, we describes data structure of a developed program which required to change CAD files to wiring diagrams and to generate them to data of tracks. And we show the result that the simulator, using the data structure, controls speed and route of trains without problems.

• 대한조선학회논문집
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• 제52권2호
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• pp.110-118
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• 2015

Weather routing method is one of the best practices of SEEMP (Ship Energy Efficiency Management Plan) for fuel-efficient operation of ship. KR is carrying out a basic research for development of the weather routing algorithm and making a monitoring system by FOC (Fuel Oil Consumption) analysis compared to the reference, which is the great circle route. The added resistances applied global sea/weather data can be calculated using ship data, and the results can be corrected to ship motions. The global sea/weather data such as significant wave height, ocean current and wind data can be used to calculate the added resistances. The reference route in a usual navigation is the great circle route, which is the shortest distance route. The global sea/weather data can be divided into grids, and the nearest grid data from a ship's position can be used to apply a ocean going vessel's sea conditions. Powell method is used as an optimized routing technique to minimize FOC considered sea/weather conditions, and FOC result can be compared with the great circle route result.

• 대한산업공학회지
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• 제23권4호
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• pp.645-660
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• 1997

An application of the genetic algorithm(GA) to the loading sequencing problem in port container terminals is presented in this paper. The efficiency of loading operations in port container terminals is highly dependent on the loading sequence of export containers. In order to sequence the loading operation, we hove to determine the route of each container handling equipment (transfer crane or straddle carried in the yard during the loading operation. The route of a container handling equipment is determined in a way of minimizing the total container handling time. An encoding method is developed which keeps intermediate solutions feasible and speeds up the evolution process. We determine the sequence of each individual container which the container handling equipment picks up at each yard-bay as well as the visiting sequence of yard-bays of the equipment during the loading operation. A numerical experiment is carried out to evaluate the performance of the algorithm developed.

• 한국항행학회논문지
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• 제24권5호
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• pp.348-357
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• 2020

eVTOL PAV의 상용화에 있어 해결해야할 중요한 과제들 중 하나는 도심항공 모빌리티 운용에 따른 소음을 감소시키는 것이다. 따라서 본 논문에서는 우리나라 수도권 행정구역별 인구 분포 데이터를 분석하여 소음에 영향을 받는 인구수가 최소화될 수 있도록 AEDT (aviation environmental design tool) 소프트웨어를 사용하여 소음 우선 경로를 생성하고, 운용 시의 소음 분석을 수행하였다. 또한, 최단 거리 경로 운영 시 소음에 영향을 받는 인구수와 비교하여 소음 우선 경로가 소음 노출을 얼마만큼 감소시킬 수 있는지 분석하였다. eVTOL PAV 개발 회사에서 소음 데이터를 제공하지 않는다는 점을 감안하여 헬리콥터 모델을 사용하여 분석을 진행하였다. 결과적으로 소음 노출량을 최소화한 소음 우선 경로가 타 경로들에 비해 더 효율적임을 증명하였다.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권4호
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• pp.473-477
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• 2013

The railway developed countries in Europe, Japan such as ERTMS Regional, FFB, COMBAT, it is the stage of development or testing the train control system for the signal system of branch interval of low density. Similar to the signal system used by the mainline and branch sections of low density domestic portions not suitable in terms of maintenance operational efficiency in accordance with the installation and operation in many cases. Therefore these low-density branch railway lines required that oriented train control system of wireless communication to improve the operation efficiency and line side equipment controlled on board the train. In this paper, We was published a route on setting is the operation of the new on-board oriented train control system for controlling a line converter of the train so that it is possible to improve the operational efficiency of the branch of the low density.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권2호
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• pp.157-160
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• 2006

Nasotracheal intubation is performed routinely in maxillofacial surgery to optimize visualization of the surgical field. The CaldwellLuc operation is an approach to the maxillary sinus through the labiogingival sulcus and canine fossa. The operation is used to treat chronic maxillary sinusitis, and involves curettage of the mucosa of the maxillary sinus and the creation of an inferior meatal antrostomy. After the operation, a nasal Foley catheter is inserted into the inferior nasal meatus for the discharge of blood and tissue fluid. Then, the nostril is packed with vaseline gauze. Before the patients awaken, they experience impaired switching from nasal to oral breathing. Pulmonary edema can result from excessive negative intrathoracic pressure caused by acute airway obstruction in patients breathing spontaneously. During anesthesia and sedation, airway obstruction can occur at the levels of the pharynx and larynx. Even in patients who are awake, alteration in the ability to change the breathing route from nasal to oral may affect breathing in the presence of an airway obstruction, causing this catastrophic event. We experienced a case in which acute pulmonary edema resulted from acute airway obstruction triggered by the patient's inability to switch the breathing route from nasal to oral during emergence from anesthesia.

• Advances in aircraft and spacecraft science
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• 제5권4호
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• pp.431-444
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• 2018

Numerical simulations have been conducted to study the unstart/restart characteristics of an over-under turbine-based combined-cycle propulsion system (TBCC) inlet during the inlet transition phase. A dual-solution area exists according to the Kantrowitz theory, in which the inlet states may be different even with the same input parameters. The entire transition process was divided into five stages and the unstart/restart hysteresis loop for each stage was also obtained. These loops construct a hysteresis surface which separates the operating space of the engine into three parts: in which a) inlet can maintain a started state; b) inlet keeps an unstarted state; c) inlet state depends on its initial state. During the transition, the operation of the engine follows a certain order with different backpressures and splitter angles, namely control route, which may result in disparate inlet states. Nine control routes with different backpressures and transition stages were designed to illuminate the route-dependent behavior of the inlet. The control routes operating towards the unstart boundary can make the inlet transit from a started state into an unstarted one. But operating backward the same route cannot make the inlet restart, additional effort should be made.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.72-75
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• 2005

Uncertainty of objects in Moving Object Database is a coherent property. It has been discussed in a lot of researches on modelling and query processing. The previous studies assume that uncertain future time is determined through utilizing recent speed and direction of vehicles. This method is simple and useful for estimating the time of the near future location. However, it is not appropriate when we estimate the time of the far future location. Therefore, in this paper, we propose a concept of planned route. It is used to estimate uncertain future time, which has to be located at a given point. If the route of an object is planned beforehand its locations are uncertainly distributed near that route. By a simple projection operation, the probability that a location lies in the planned route is increased. Moreover, we identify the future time of an object based on the speed for passing the route, which is offered via a website.