• 한국항해항만학회지
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• 제40권3호
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• pp.105-111
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• 2016

우리나라 항구 주변에는 입 출항하는 많은 선박으로 인하여 해상교통흐름이 복잡하다. 이러한 선박통항의 안전과 효율성을 증진하기 위해 우리나라에서는 해상교통관제 서비스를 시행하고 있다. 24시간 쉴 틈이 없는 해상교통 관제사들의 노력에도 불구하고 관제구역 내에서의 충돌사고는 지속적으로 발생하고 있다. 해상교통관제에 관한 기본적인 절차는 있지만 선박간 위험에 대한 판단 기준이 없어 VTS관제사의 주관적인 판단으로 관제를 실시하고 있는 실정이다. 이에 본 연구는 부산항관제 VHF채널을 3일간 청취하여, 교신내용을 분석하였다. 부산항관제 교신 중 통항에 관련된 사항을 충돌위험도 모델에 적용하여 위험도로 표현하였으며, 관제사들이 선박에게 권고 지시를 하는 시점의 위험도를 조우상황별, 관제사의 경력별, 주 야간별로 분석하였다. 본 연구는 관제사의 정량적인 관제 시점 연구에 기초 자료로 활용될 수 있을 것으로 판단된다.

• 한국항해항만학회지
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• 제37권6호
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• pp.587-595
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• 2013

항만건설 및 운영에서 해양교통시설의 설치와 운영은 해상충돌방지 및 안전에서 매우 중요한 인자이다. 그리고, 해상교통시설의 설치 및 운영은 IMO SOLAS 5장 제13조에 의하여 당국의 의무사항으로 규정되어 있다. 해양교통시설은 과거의 시각적(광학, 형상) 시설에서 AIS, DGPS 및 기타 전파표지 등을 활용한 e-Navigation의 개념으로 발전하고 있다. 그러나 이러한 해양교통시설의 자동화 흐름에도 불구하고 선박의 안전한 항해를 위한 광파표지 및 형상표지의 역할은 여전히 절대적이다. 본 연구에서는 시각표지의 운영관리 효율을 향상시키기 위한 해양교통시설 서비스수준의 결정방법으로 해상교통관련 전체 시설을 하나의 관리시스템으로 조합하고 더욱 효율적인 시스템 관리방안으로서 항로표지 운영율을 제안하였다. 해외의 서비스 수준에 대한 비교와 이론적 배경을 분석하고, 제안된 서비스수준을 인천해역에 실제 적용하여 항로의 안전성을 평가한 사례를 제시하였다.

• 상하수도학회지
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• 제18권5호
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• pp.573-579
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• 2004

Electroflotation, which is used as an alternative to sedimentation, is a separation treatment process that uses small bubbles to remove low-density particulates. Making allowances for recent collision efficiency diagram based on trajectory analysis, it is necessary to tailor zeta potential of bubbles that collide with negatively charged particles. In this paper, the study was performed to investigate the effects of magnesium and aluminium ions on zeta potential of bubbles. And, it was studied to find out factors which could affect the positively charged bubbles. Consequently, zeta potential of bubbles increased both with higher concentration of metal ions and in the acidic pH value. And, a probable principle that explained the procedure of charge reversal could be a combined mechanism with both specific adsorption of hydroxylated species and laying down of hydroxide precipitate. It also depended on the metal ion concentration in the solution to display its capacity to control the bubble surface.

• 한국안전학회지
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• 제32권1호
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• pp.1-8
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• 2017

In industry AGV's(automated guided vehicles) that can detect and follow guidelines drawn on the factory floor using magnetic or optical sensors are widely used. However, such AGV's without preview capability cannot effectively avoid collision with obstacles that may occasionally pass through the guideline. Furthermore, without preview information, they consume much energy at the right angle corners as they have to make sudden directional change. Also, the risk of dropping payloads increases in such situations. In this study, infrared preview sensors were adopted to a mobile robot for detecting not only the current position but also the forward position of the guideline and the preview control technique was applied to optimally control the mobile robot's motion using the information from the infrared preview sensors. Then the effectiveness of this approach was investigated through a series of experiments. The experimental result shows that the proposed approach is effective for safety enhancement as well as for better efficiency.

• 제어로봇시스템학회논문지
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• 제16권9호
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• pp.905-912
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• 2010

Modern version of advanced supersonic fighter have ATCS (Automatic Thrust Control System) to maximum flight safety, fuel efficiency and mission capability the integrated advanced autopilot system such as TFS (Terrain Following System), GCAS (Ground Collision Avoidance System) and AARS (Automatic Attitude Recovery System) and etc. This paper addresses the design and verification of ATCS based on advanced supersonic trainer in HILS (Hardware In the Loop Simulator) with minimum hardware modification to reduce of development cost and maintain of system reliability. The function of ATCS is consisted of target speed hold mode in UA (Up and Away) and angle of attack hold mode in PA (Power Approach). The real-time pilot evaluation reveals that pilot workload is minimized in cruise and approach flight stage by ATCS.

• Journal of information and communication convergence engineering
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• 제6권4호
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• pp.364-369
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• 2008

The FSA algorithm for identifying multiple tags in RFID systems is based on the slotted ALOHA scheme with a fixed frame size. The performance of FSA algorithm is dependent on the frame size and the number of tags in the reader's identification range. Therefore, this paper proposes a new ODFSA. The proposed ODFSA algorithm dynamically allocates the optimal frame size at every frame based on the number of tags in the reader's identification range. According to the simulation results, the system efficiency of the proposed algorithm should be maintained optimally. Also, the proposed algorithm always obtained the minimum tag identification delay.

• 한국안전학회지
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• 제8권3호
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• pp.56-63
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• 1993

In this study the ultrasound which has the properties of mixing, surface cleaning effect, increasing of the effective reaction surface area and increasing of the effective collision frequency, was used to enhance the recovering efficiency of Cu from the Cu-ion containning waste water. The ultrasonic reactor used in this study was dsigned and constructed for improving the disadvantage of the existing ultrasonic reactor From the experimental result and its analysis. we obtained following conclusions. 1. The ultrasound increased the rate of electrochemical deposition to 582.2% in maximum at the Condition of 0.1M-CuSO$_4$and 2.1V-overpotential. 2. This study gave the possibility of the scale-up of ultrasonic reactor and In particular, ultrasonic reactor would be effective in treatment of waste water contains a low concentration of Cu ion.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2003년도 추계학술발표논문집 (상)
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• pp.515-518
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• 2003

좋은 3D 엔진이란 객체들의 상호 작용을 실세계와 유사하게 표현하는 물리라 엔진을 말하다. 충돌은 이런 상호작용 중의 하나이며, 충돌 유무 검사와, 충돌 지점, 충돌후의 반응을 다룬다. 대부분의 물리학 엔진과 같이 충돌 검사도 정확하게 검출하려면 많은 시간이 소요된다. 그래서 개발자들은 정밀도와 시간을 절충할 수 있는 기법을 사용한다. 이렇게 사용되는 기법들이 얼마만큼의 효율성을 가지는지 검증하는 방법은 많이 제시되지 않았다. 본 논문에서는 효율성의 기준을 연산 시간과 정확도로 책정했으며, 실제 개발에 적용되고 있는 알고리즘을 게임에서 발생하는 표본 상황에 적용하여 테스트 한 결과를 분석하고, 게임에 응용될 수 있는 모델을 제시한다.

• 소성∙가공
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• 제24권5호
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• pp.354-360
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• 2015

AHSS (Advanced High Strength Steels) has been increasingly employed by global automotive OEMs in order to satisfy strengthened regulations and reduce weight for fuel efficiency. Hot stamping using boron steels in AHSS increases not only formability but also strength. The typical hot-stamped automotive part is the center pillar that is critical for vehicle side impact. However, the hot-stamped part can be risky for the passenger safety caused by brittle fracture under a vehicle collision. The high power diode laser is suitable for the heat treatment giving AHSS increased elongation that prevents brittle fracture in car crash. Therefore, local softening by laser heat treatment for energy absorption area on the hot-stamped part improves crash-worthiness.

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.164-169
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• 2009

An RFID system consists of radio frequency tags attached to objects that need to be identified and one or more electromagnetic readers. Unlike the traditional bar code system, the great benefit of RFID technology is that it allows information to be read without requiring contact between the tag and the reader. For this contact-less feature, RFID technology in the near future will become an attractive alternative to bar code in many application fields. In almost all the 13.56MHz RFID systems, FSA (Framed Slot ALOHA) algorithm is used for identifying multiple tags in the reader's identification range. In FSA algorithm, the tag identification time and system efficiency depend mainly on the number of tags and frame size. In this paper, we propose a tag number estimation scheme and a dynamic frame size allocation scheme based on the estimated number of tags.