• 한국항해학회지
• /
• 제7권2호
• /
• pp.1-45
• /
• 1983

This paper concerns the applications of the Kalman filter to navigation and the develment of computer programs of the navigational calculations. Methods to apply the Kalman filter to celestial fix, fix by cross bearing and cocked hat are proposed, and numerical simulations under various noise conditiions are conducted. The accuracy of the optimal positions obtained by the Kalman filter is compared with that of the fixed positiions by radial error method. In the case of celestial fix, an algorithm to estimate the optimal positions by using the linear Kalman filter is presented. The optimal positions by the Kalman filter are compared with the running fixes and with the most probable positions obtained from a single line of position. It is confirmed that the resutls of the proposed method are more accurate than the others. In practical piloting, bearings are generally measured intermittently and the measurement process is nonlinear. It is, therefore, difficult for us to apply the Kalman filter to fix by cross bearing. In order to be used in such an unfavorable case, the extended Kalman filter is revised and the aplicability of the revised extended Kalman filter is checked by numerical simulation under various noise conditions. In a cocked hat, an inside or outside fix is dependent only upon azimuth spread, if the error of each line of position is assumed to be equal both in magnitude and sign. A new technique of selecting a ship's position between an inside fix and an outside fix in a cocked hat by using fix determinant derived from the equation of three lines of position is also presented. The relations among the optimal position by Kalman filter, incentre (or excentre) and random error centtre of the cocked hat are discussed theoretically and the accuracy of the optimal position is compared with that of the others by numerical simulation.

• 수산해양교육연구
• /
• 제26권1호
• /
• pp.81-97
• /
• 2014

The purpose of this study is to analyze the level of interest in the achievement evaluation system, under the assumption that the teacher is an important element of curriculum. For this study, surveys targeting the 150 middle school teachers from 6 schools in Pusan was conducted. A questionnaire based CBAM model was used as research tools. For data analysis, mean of relative strength by teacher's level of interest was calculated. And MANOVA was used to investigate the difference among level of interest according to teachers' background such as sex, age, career, job position, and the grade they taught. The results of the analysis are summarized as follows. First, the middle school teachers' overall interest for achievement evaluation system is low. Teachers showed a typical pattern appeared in the early stages of change. They have little interest in the achievement evaluation system. And they should try to fix and change the achievement evaluation system rather than cooperate it. Second, as a result of this analysis of the difference according to teachers' background, no significant differences were found in most of the variables. Significant differences were found only in age, career, and job position from step 0. In running the post hoc, teachers who have less careers, lower positions, and younger ages had less interest in achievement evaluation system.

• 한국군사과학기술학회지
• /
• 제6권1호
• /
• pp.21-29
• /
• 2003

The Strap Down Inertial Measurement Unit(SDIMU) is recently used for the sensor package of the modern underwater vehicles such as torpedoes and unmanned underwater-vehicles. For using SDIMU, an initial alignment must be carried out before the fire or navigation stage. The general initial alignment methods require that a mother vehicle Is a stationary condition or the Inertial Navigation System(INS) of vehicle is received the specific of data navigation from the mother vehicle. But an underwater vehicle dropped from aircraft is hard to satisfy above both necessary conditions of the general initial alignment. So, we suggest a new strap down initial alignment method of an underwater vehicle dropped from aircraft without using any aided sensors. The highlight point of this method is that a period of initial alignment is not before the fire but during running stage to fix alignment error. And we verify it by analyzing various data of S/W simulations, Hardware In the Loop Simulation(HILS) tests and sea trials.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 추계학술대회 논문집
• /
• pp.666-672
• /
• 2008

Train wheels are the most important part of the high-speed rail system with supporting body, running stably and safely. Wheel exchange and fix plan is computed by the worker who managing entire Train Maintenance Process based on his know-how so that this system is losing its reliability and accuracy. And predicting of the wheel's lifetime is absolutely difficult matter because of uncertainty between trains like mileage of the type of trains, condition of operation, curve section and wheel's cutting pattern. Therefore workers always used to hold many wheels. For this reason, the cost of stock is soar when the level of stock was normal. If the stock is sufficient, the cost of stock will rise. On the other hand, If the stock is deficient, we would have trouble that the plan of the train maintenance process will be failed. Thus this paper aimed at application that "Wheel Managing System" which is able to predict wheel's life-cycle and demands under the RIMS(Rolling-Stock Information Maintenance System) with analysing wheel exchanging and cutting status considering economical or stable aspects.

• 한국통신학회논문지
• /
• 제41권3호
• /
• pp.347-358
• /
• 2016

본 논문은 사용자의 행동을 실시간 인지하여 그 행동과 연동하여 생체 신호를 측정 할 수 있는 착용형 단말 소프트웨어 구조를 제안한다. 착용형 단말은 사용자가 일상생활 동안 항상 착용하고 있기 때문에 이러한 장치를 통하여 생체 신호를 측정하는 것은 사용자 행동과 관련된 건강 정보를 얻을 수 있게 해준다. 이 중 산소포화도와 심박수는 사용자가 운동을 하거나 수면을 취하는 동안 변화를 측정하면 호흡기 상태를 진단하는데 사용할 수 있다. 그러나 이런 생체 신호를 생활 중에 측정하는데 있어서 기존의 방법과 같이 연속적으로 측정하는 것은 움직임으로 인한 신호 왜곡 때문에 정확성을 떨어뜨리게 된다. 또 왜곡을 고치기 위해서 복잡한 알고리즘을 적용하는 것도 착용형 단말의 한정적인 자원을 고려하면 적절하지 않다. 따라서 본 논문에서는 연산이 간단한 필터와 가속도 센서를 이용하여 사용자 행동을 먼저 판단하고 그에 연동하여 정확한 생체신호를 측정할 수 있는 착용형 단말 소프트웨어 구조를 제안한다.

• Bulletin of the Korean Chemical Society
• /
• 제33권4호
• /
• pp.1135-1140
• /
• 2012

An electrochromatographic microchip with carboxyl-group-derivatized mono-disperse silica packing was prepared from the corresponding colloidal silica solution by utilizing capillary action and self-assembly behavior. The silica beads in water were primed by the capillary action toward the ends of cross-patterned microchannel on a cyclic olefinic copolymer (COC) substrate. Slow evaporation of water at the front of packing promoted the self-assembled packing of the beads. After thermally binding a cover plate on the chip substrate, reservoirs for sample solutions were fabricated at the ends of the microchannel. The packing at the entrances of the microchannel was silver coated to fix utilizing an electroless silver-plating technique to prevent the erosion of the packed structure caused by the sudden switching of a high voltage DC power source. The electrochromatographic behavior of the microchip was explored and compared to that of the microchip with bare silica packing in basic borate buffer. Electrophoretic migration of Rhodamine B was dominant in the microchip with the carboxyl-derivatized silica packing that resulted in a migration approximated twice as fast, while the reversible adsorption was dominant in the bare silica-packed microchip. Not only the faster migration rates of the negatively charged FITC-derivatives of amino acids but also the different migration due to the charge interaction at the packing surface were observed. The electrochromatographic characteristics were studied in detail and compared with those of the bare silica packed microchip in terms of the packing material, the separation potential, pH of the running buffer, and also the separation channel length.

• 한국정보통신학회논문지
• /
• 제22권4호
• /
• pp.691-699
• /
• 2018

천문을 이용한 측위는 과거로부터 육분의(Sextant)를 이용하여 시행하여 왔다. 주로 천측력과 천측계산표를 이용하여 St. Hilaire 방식을 사용하였는데, 현대에는 IT 기술과의 접목으로 LOP(Line of Position) 방식을 원활히 사용할 수 있게 되었다. 그러나 과거의 방식 대비 LOP 방식은 항상 위치가 진위(True Position)와 허위(False Position) 두 가지로 나타나게 되는데, 이를 항해사가 반드시 판별하지 않으면 안 된다. 따라서 본 논문에서는 LOP 방식에서 발생하는 허위의 제거를 위해 방위를 이용하는 알고리즘을 제안한다. 특히 방위를 이용하게 되는 이론적 고찰을 여러 방법으로 제시하여 그 타당성을 확보하였으며, 시뮬레이션을 통하여 본 논문의 이론적 근거가 타당성을 가지고 있음을 평가하였다.

• 한국항만경제학회지
• /
• 제29권4호
• /
• pp.27-53
• /
• 2013

용선계약에서 정박기간은 확정할 수도 있고 미확정인 상태로 그 항만의 관습적인 방법에 따라 선적 및 양하를 행하는 것이 일반적인 관례이다. 항만설비나 기타 제반 여건이 좋아 하역작업이 조속히 이루어 질 수 있는 상황이라면 선주는 그 항만의 관습에 따라 행하는 하역작업을 허용할 수도 있으나, 항만이 신설되거나 여건이 좋지 않을 경우 일정한 기한 내에 작업을 행하도록 용선 계약상에 명문화 하는 것이 통상적인 운송계약방식이다. 그 이유는 용선자나 선주가 조속한 하역작업을 위해 각자의 권리와 의무에 최선을 다하고, 가능한 조속히 하역을 완료하여 선박이 항만에서 체류하게 되는 시간을 최소화시켜 운항효율성을 제고하는 한편, 그에 따라 운임과 항만비용 등 제반 운송비용을 절감함으로써, 용선자나 선주가 공동의 이익을 실현할 수 있기 때문이다. 이러한 기한부 하역조건에는 용선계약의 양식과 화물의 종류 등에 따라 매우 다양하게 표한할 수 있다. 그러나 이러한 용어에 관하여 용선자나 선주의 명확한 이해부족으로 많은 분쟁이 발생한다. 따라서 본고에서는 용선계약에서 언급되는 기한부 하역조건 또는 정박기간의 조건을 영국법의 판례로 살펴보고 그에 따른 법적의미와 해석기준을 제시하여, 국제무역과 해운기업의 실무에 도움이 되고자 한다.