• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1287-1288
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• 2013

최근에, 스마트 기기를 이용한 다양한 선 주문 시스템이 나오고 있다. 선 주문 하고, 일정 기한 동안 수령하는 현재의 선 주문 시스템에서 발전하기 위해 필요한 정보는 사용자의 도착시간이다. 따라서 본 논문에서는 선 주문 시스템 내에서 사용자의 도착시간을 예상하는 방안을 제안한다. 이를 통해 선 주문 시스템은 더욱 다양한 영역으로 활용될 수 있을 것이다.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.111-117
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• 2017

The arrival time of rescue ships is very important in the event of distress. This paper presents the development of experimental data to calculate the arrival time of rescue ships. The ship's traffic probability distribution was used. Mokpo Port was selected as the area of study, and AIS data for a 1 year period were used. For the ship's traffic probability distribution, a gateline was established. The lateral range distribution was calculated and fitted to the normal distribution and two Gaussian mixture distributions (GMD2), and each parameter was extracted. After the locations of ${\mu}$, ${\mu}{\pm}1{\sigma}$ of the normal distribution and ${\mu}_1$ of the two Gaussian mixture distribution(GMD2) were set as waypoints, the location and probability were determined. A scenario was established in relation to each type of parameter. Thus, the arrival time can be calculated.

• Journal of Korea Port Economic Association
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• v.28 no.3
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• pp.167-192
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• 2012

The purpose of the study aims to analyse the judgement criterion of arrived ship under voyage charterparty with the Merida Case. A ship is an arrived ship if she is in port and either able to proceed immediately to a berth or in such a position that she is at the immediate and effective disposition of the chaterparty. Identification of the specified destination-whether berth or port-impacts on the incidence of loss occasioned by delay in loading or discharging, when the delay is due to the place at which the vessel is obliged by the terms of the charterparty to load or discharge her cargo being occupied by other shipping. The Merida case is an appeal by the charterers from a final Arbitration award of two very experienced arbitrators, dated 20th April, 2009. The arbitrators held that a voyage charterparty, dated 5th February, 2007, of the vessel, The M/V Merida, entered into between charterers and the owners, was a port rather than a berth Charterparty. The Primary relevance of this distinction does to the allocation, as between owners and charterers, of the risk of delay caused by congestion at load and discharge ports. The question of law arising in this appeal is whether the arbitrators were right to conclude that the charterparty was a port and not a berth charterparty. The arbitrators additionary placed some reliance on a post-contractual e-mail from the agents, which suggested that charterers did not dispute the validity of the NOR-and, hence, that this was a port charterparty.

• Journal of Astronomy and Space Sciences
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• v.20 no.4
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• pp.299-312
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• 2003

Earth to Mars ballistic mission opportunities from Naro Space Center are studied. Determining ballistic mission opportunities can be divided into two major parts, i.e. the launch window and the daily launch window determination. At the launch window determination parts, Porkchop diagrams of Earth launch C3 magnitude, total mission duration, declination of $V_{\infty}$ vector at the Earth launch, and declination & right ascension of $V_{\infty}$ vector at the Mars arrival are examined. The location of launch site and rotation effects of the Earth are considered during the daily launch window determination parts. Using Lambert method, various Porkchop diagrams of launching in 2027 are examined for example. The daily launch window of Naro Space Center at that year was checked to verify the launch possibility by comparing with the Kennedy Space Center.

• Journal of the Korea Society for Simulation
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• v.17 no.3
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• pp.63-73
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• 2008

The aim of study is to analyze the berth occupancy rate according to the ship size. P Iron and steel company operate exclusive bulk terminal at P port and G port and the depth of water at berth are not so equal each other. And to reduce the sea transport cost between loading port and unloading port P and G, P company increases the number of large ship while ship scheduling. But it causes to increase the berth congestion at the specific water depth berth owing to the draught of large ship. At this point, usually ship waiting time starts to rise even at low levels of berth occupancy rate, and will rise more and more sharply at the level of full utilization. But it is not common at exclusive terminal like P port and G port. Bulk ships arrive at port according to the early planned arrival time and the coefficient of variation of ship arrival time is not so big. So queueing time at exclusive terminal does not rise sharply near 80-90 berth occupancy rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.86-89
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• 2018

This paper introduces a ZigBee network-based four-lane lap time measurement system that can be set up for short-distance races. The instructions "Ready-Set-Go" can be announced at the entry point node when the start button is pushed, and foot switches installed at the exit point node can be stepped on by the runner for lap time measurement of the race. The start and exit point nodes are connected to a ZigBee network to communicate time synchronization packets. The exit point node maintains synchronized local time within 10 ms at most. The system does not need expensive measurement equipment and provides lap time recording in a more convenient manner than conventional lap time measurement methods.

• Defense and Technology
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• no.11 s.297
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• pp.32-43
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• 2003

달에 착륙한 지 6시간 20분이 지난 후 암스트롱은 온 인류가 긴장하여 TV로 지켜보는 가운데 착륙선의 문을 열고 아홉 계단의 달착륙선 사다리를 천천히 그리고 조심스럽게 내려오기 시작하였다. 인간이 지구상에 그 모습을 나타낸 이후 40만km의 먼거리에 있는 달은 인간에게는 바라볼 수는 있지만 영원히 닿을 수 없는 것으로만 생각하였는데, 4일간의 비행 끝에 전인미답의 달에 도착하여 역사적인 첫 발을 내딛는 암스트롱에게는 형용할 수 없는 감회와 감격의 순간이었을 것이다. 그는 용솟음치는 흥분을 누를 수 없었는지 착륙 직후 "이것은 한 인간에게는 작은 발걸음이지만 인류에게는 커다람 도약이다"라고 부르짖었다.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.451-462
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• 2005

Optimal Trajectory Correction Maneuver (TCM) design algorithm has been developed using the B-plane targeting method for future Korean Mars missions. For every-mission phase, trajectory informations can also be obtained using this developed algorithms which are essential to design optimal TCM strategy. The information were computed under minimum requiring perturbations to design Mars missions. Spacecraft can not be reached at designed aim point because of unexpected trajectory errors, caused by many perturbations and errors due to operating impulsive maneuvers during the cruising phase of missions. To maintain spacecraft's appropriate trajectory and deliver it to the designed aim point, B-plane targeting techniques are needed. A software NPSOL is used to solve this optimization problem, with the performance index of minimizing total amount of TCM's magnitude. And also executing time of maneuvers on be controlled for the user defined maneuver number $(1\~5)$ of TCMs. The constraints, the Mars arrival B-plane boundary conditions, are formulated for the problem. Results of this work show the ability to design and analyze overall Mars missions, from the Earth launch phase to Mars arrival phase including capture orbit status for future Korean Mars missions

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.162.1-162.1
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• 2012

한국형 달 착륙선의 안전하고 효율적인 달 착륙을 위해 임무 시나리오 시뮬레이션을 수행하였다. 달 착륙은 보통 두 가지 방법이 사용되는데, 지구에서 출발하여 달에 도착한 후 달착륙지에 직접 착륙하는 방법과 달의 주차궤도를 돌다가 달 착륙지에 착륙하는 방법이 있다. 미국의 Surveyor호는 직접 착륙 방법을 사용하였고 아폴로 시리즈는 달 궤도를 공전하다가 착륙하는 방법을 사용하였다. 본 연구에서는 두 가지 방법을 모두 사용하여 착륙 임무 시나리오를 시뮬레이션을 수행한 후 장단점을 비교분석하였다. 달 주차궤도를 이용한 착륙은 달고도 100km에서 공전을 하다가 고도 15km까지 하강한 후 Powered descent 단계를 통해 착륙지에 착륙하는데 Powered descent 단계는 다시 감속단계, 접근 단계, 최종 하강 단계로 나뉘어진다. 달 착륙선은 나로우주센터에서 KSLV-2에 실려 2025년에 발사되며, 달 착륙지는 달의 과학적 임무를 고려하여 달 남극 근처로 가정하였다. 달 착륙 시뮬레이션을 통해 달 착륙선의 비행 궤적과 필요한 연료량 계산 등의 정보를 통해 직접 착륙 방법과 달 주차궤도를 이용하는 방법의 장단점을 확인할 수 있었다.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.64-73
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• 2020

This paper presented a methodology for calculating daily load curves per city by taking into account the charging/discharging location of electric vehicle. In other words, this is the daily load curve calculation algorithm by city, which takes into account the charging/discharging location of electric vehicles, so that the impact of loads generated by charging/discharging of electric vehicles on the power grid can be easily understood in certain cities. Specifically, in accordance with the PEVs share scenario, the PEVs discharge power was calculated to reflect both the characteristics of the arriving vehicle in the morning and the SMP plan after establishing a assumption that the electric vehicle arrived at work in the morning and the electric vehicle arrived at home in the afternoon for each of the charging/discharging locations, that is, work and home, of electric vehicles in the city. After calculating the daily load curve for each charging/discharging power type for the PEVs charging strategy, which takes into account both the characteristics of the vehicle arriving at home in the afternoon and the TOU fare system, it was analyzed by comparing the impact assessment on the grid by adding the existing load.