• 수산해양기술연구
• /
• 제32권2호
• /
• pp.132-147
• /
• 1996

The optimal design of floating type fisheries facilities in the open sea is demanded considering with the severe hydrodynamic forces on floating body, mooring tension and holding force of anchor. For conserving the facilities in most effective state, design and selection of anchor system is one of the most important fundamental subject. To enhance the design procedure of anchor system the holding forces of anchor are investigated by the hydraulic model test and are compared with the typical conventional results for various anchors. Applicability of previous estimation methods of holding force are checked and holding mechanism of anchor is discussed. Using the results a new computational concept of holding force is suggested considering mainly the effects of passive soil pressure (resistance), steady soil pressure, and surface friction etc. The new estimation method is proved as a feasible one by comparing the results of hydraulic model experiments. Applicability of various anchors to the anchor system on open sea fisheries structures is comprehensively reviewed using the present model tests and previous study results in the viewpoint of economy, construction and stability etc. Using the results, fundamental anchoring system design procedures are suggested to apply huge marine ranching complex with increase of the holding capacity of anchor under the optimum cost.

• 한국태양에너지학회 논문집
• /
• 제33권2호
• /
• pp.84-92
• /
• 2013

Blinds are a common type of shading device and are increasingly operated automatically to overcome the limitations of manual operation. Automated blinds need to be controlled to maximize benefits of daylight in the point of occupant comfort and energy consumption. However, the previous control methods could cause occupant's distractions by the undesirable control time interval and amount of blind movement. A few researches suggested the control concept for minimizing occupant's distractions by automatic blind control, but they did not provide optimal control algorithm to be useful in practice. In this paper, we propose an optimal control algorithm for automated blinds that can maximize not only visual comfort but also sunlight penetration into buildings based on occupants' preferences on blind movement and sunlight. The proposed control algorithm can prevent solar glare on workplane and minimize occupant's distractions to maximize occupants' visual comfort.

• 한국철도학회논문집
• /
• 제11권3호
• /
• pp.286-293
• /
• 2008

본 연구에서는 국내 실정에 적합한 표준 기반의 코드체계를 구현하기 위하여 u-FOS 시스템을 적용하고 물류정보를 인식하기 위하여 900MHz 대역의 수동형과 2.45GHz 대역의 능동형 RFID 시스템을 이용하였다. RFID 정보를 획득하기 위하여 철도차량과 화물차량의 이동속도 및 최적으로 인식이 가능한 부착위치를 현장 테스트를 통해 확보하였다. 인식된 RFID 정보는 u-FOS 시스템으로 전달할 수 있도록 하고, RFID ODS 네트워크 상에서 육송 물류 관리를 하기 위하여 표준코드체계를 KKR코드체계로 제시함으로써 연관기관 및 기업이 쉽고 빠르게 도입한 수 있도록 가이드라인을 제시하였다.

• Computational Structural Engineering : An International Journal
• /
• 제3권1호
• /
• pp.61-68
• /
• 2003

A recently developed semi-active control system employing magneto-rheological (MR) fluid dampers is applied to vibration control of a wind excited tall building. The semi-active control system with MR fluid dampers appears to have the reliability of passive control devices and the adaptability of fully active control systems. The system requires only small power source, which is critical during severe events, when the main power source may fail. Numerical simulation studies are performed to demonstrate the efficiency of the MR dampers on the third ASCE benchmark problem. Multiple MR dampers are assumed to be installed in the 76-story building. Genetic algorithm is applied to determine the optimal locations and capacities of the MR dampers. Clipped optimal controller is designed to control the MR dampers based on the acceleration feedback. To verify the robustness with respect to the variation of the external wind force, several cases with different wind forces are considered in the numerical simulation. Simulation results show that the semi-actively controlled MR dampers can effectively reduce both the peak and RMS responses the tall building under various wind force conditions. The control performance of the MR dampers for wind is found to be fairly similar to the performance of an active tuned mass damper.

• 한국군사과학기술학회지
• /
• 제10권2호
• /
• pp.90-99
• /
• 2007

We demonstrate an 80km-reach 64-channel DWDM-PON based on wavelength-locked F-P LDs by changing the position of the C-band BLS for upstream channels from the CO to the RN. It mitigates the necessity of the high power C-band BLS and its handling problems. It also reduces back scattering induced penalty. We obtained less than $10^{-6}$ PLRs in all 128channels through 80km SMF. We also demonstrate a 240km-reach DWDM-PON based on wavelength-locked F-P LDs by adding a bidirectional erbium-doped fiber amplifier(EDFA). We show packet-loss-free transmission in all 128channels at 125 Mb/s per channel over 240km SMF We report the detuning effect of arrayed waveguide gratings(AWGs) and crosstalk effect in the implemented system. We Propose an architecture of a next generation defense wire communication system with the demonstrated long-reach DWDM-PON.

• KIEAE Journal
• /
• 제9권5호
• /
• pp.97-104
• /
• 2009

In the process of urban development, the increase in the number and the complexity of urban facilities gives rise to a variety of problems, such as increase in construction and maintenance cost. In particular, taking into account the fact that an emergency situation in an urban facility can cause substantial loss of property as well as casualties, it becomes important to intelligently perceive states of facilities and properly execute countermeasures through real-time monitoring. In recent years, practitioners and researchers have made efforts to improve current passive and manpower-dependent facility management systems to be more active and intelligent, by applying diverse ubiquitous computing technologies for the u-City project. In this study, after discussing major drawbacks of the conventional facilities management, the concept and the model of a sensor-based integrated intelligent management system for urban facilities are proposed. The proposed model, by analyzing and processing real-time sensor data from urban facilities, not only supports the management of individual facilities, but also enables the detection of complex facility-related events and the process of their countermeasures. This active and intelligent management of urban facilities is expected to overcome the limitation of the conventional facilities management, and provide more suitable facility management services for the u-City development.

• 국제초고층학회논문집
• /
• 제2권2호
• /
• pp.131-139
• /
• 2013

The field of structural fire engineering has evolved within the construction industry, driven largely by the acceptance of performance-based or goal-based design. This evolution has brought two disciplines very close together - that of structural engineering and fire engineering. This paper presents an overview of structural systems that are frequently adopted in tall building design; typical beams and columns, concrete filled steel tube columns and long span beams with web openings. It is shown that these structural members require a structural analysis in relation to their temperature evolution and failure modes to determine adequate thermal protection for a given fire resistance period. When this is accounted for, a more explicit understanding of the behaviour of the structure and significant cost savings can be achieved. This paper demonstrates the importance of structural fire assessments in the context of tall building design. It is shown that structural engineers are more than capable of assessing structural capacity in the event of fire using published methodologies. Rather than assumed performance, this approach can result in a safe and quantified design in the event of a fire.

• 한국주거학회논문집
• /
• 제15권2호
• /
• pp.87-96
• /
• 2004

In this study, we analyzed the state of outdoor-space use and green-environment development for apartment residents, and investigated their ways of thinking on nature orientation and green environment. The results are as follows. 1) The ways of thinking and actual use of outdoor space by apartment residents appear different. 2) Due to the difference of apartment locations and complex environments, the state and reason of green environment construction are different between the residents of high-rise and low-storied apartments. 3) The residents of the low-storied apartments are more satisfied with the green environments of the complex than those of the high-rise apartments. In addition, constructing the green environment in a balcony and outdoor space enhances the satisfaction level of the apartment residents. 4) The residents of the low-storied apartments are passive in nature orientation, while those of the high-rise apartments are active. 5) Depending on the types of nature orientation, the apartment residents are grouped as 'people of nature experience', 'nature appreciators', or 'people of living-thing contact'. These groups show different patterns on the ways of thinking for outdoor space and green environment.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.828-830
• /
• 2003

We have constructed a level-1 processor to generate brightness temperatures using the direct-broadcast data from the passive microwave radiometer onboard Aqua satellite. Although 50-minute half-orbit data, called a granule, are being routinely produced, to our knowledge, this is the first attempt to process about 10-minute long direct-broadcast data. We modified the processor designed for a granule to process the direct-broadcast data. After the modification, our brightness temperature product differs from the reference by 0.2K rms. Sea surface temperatures are retrieved to demonstrate the utility of AMSR-E.

• Structural Engineering and Mechanics
• /
• 제76권3호
• /
• pp.367-378
• /
• 2020

This paper presents a new design concept for ocean nuclear power plants (ONPPs) using a tension leg platform (TLP). The system-integrated modular advanced reactor, which is one of the successful small modular reactors, is mounted for demonstration. The authors define the design requirements and parameters, modularize and rearrange the nuclear and other facilities, and propose a new total general arrangement. The most fundamental level of design results for the platform and tendon system are provided, and the construction procedure and safety features are discussed. The integrated passive safety system developed for the gravity based structure-type ONPP is also available in the TLP-type ONPP with minor modifications. The safety system fully utilizes the benefits of the ocean environment, and enhances the safety features of the proposed concept. For the verification of the design concept, hydrodynamic analyses are performed using the commercial software ANSYS AQWA with the Pierson-Moskowitz and JONSWAP wave spectra that represent various ocean environments and the results are discussed.