• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.5
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• pp.450-454
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• 2003

This paper proposes a new driving scheme for single-phase SRM. The driving scheme is very simple and inexpensive. By use of this scheme, simple power devices based on low switching losses enable to high efficiency SRM drive. Starting, One of the main problem in single-phase SRM is overcame by a new starting algorithm with one hall sensor and a parting magnet. The proposed single phase SRM has a high efficiency and robust drive characteristics compared to that of a universal motor.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1231-1236
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• 2008

Since the bi-modal tram is too long so that the traditional steering system controlled only the first axle increases its turning radius, it is not suitable to the domestic road environment. In addition, it become hard to make fine parking with the traditional steering system. To resolve the problem, the bi-modal tram requires an all wheel steering system (AWS) that the second axle is controlled by the first axle's degree and the velocity of vehicle, and the third axle is steered by the articulation angle's degree and the velocity of degree. This paper addresses the factors for the AWS ECU design, the strategies to solve the problems, the core technologies for the implementation, and also the outcomes and analysis of the performance evaluation of implemented system.

• Journal of Advanced Navigation Technology
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• v.2 no.1
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• pp.61-67
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• 1998

In this paper, we have described the Ramp Activity Coordination Expert System (RACES) which can solve aircraft parking problems. RACES includes a knowledge-based scheduling problem which assigns every daily arriving and departing flight to the gates and remote spots with the domain specific knowledge and heuristics acquired from human experts. RACES processes complex scheduling problem such as dynamic inter-relations among the characteristics of remote spots/gates and aircraft with various other constraints, for example, custome and ground handling factors at an airport. By user-driven modeling for end users and knowledge-driven near optimal scheduling acquired from human experts, RACES can produce parking schedules of aircraft in about 20 seconds for about 400 daily flights, whereas it normally takes about 4 to 5 hours by human experts. Scheduling results in the form of Gantt charts produced by the RACES are also accepted by the domain experts. RACES is also designed to deal with the partial adjustment of the schedule when unexpected events occur. After daily scheduling is completed, the messages for aircraft changes and delay messages are reflected and updated into the schedule according to the knowledge of the domain experts. By analyzing the knowledge model of the domain expert, the reactive scheduling steps are effectively represented as rules and the scenarios of the Graphic User Interfaces (GUI) are designed. Since the modification of the aircraft dispositions such as aircraft changes and cancellations of flights are reflected to the current schedule, the modification should be notified to RACES from the mainframe for the reactive scheduling. The adjustments of the schedule are made semi-automatically by RACES since there are many irregularities in dealing with the partial rescheduling.

• Journal of the Korea Safety Management & Science
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• v.18 no.1
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• pp.1-8
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• 2016

This study was conducted by survey and inspection of stair passage leading lights in shopping buildings which are more than 5 stories and have an underground parking lot located at Pyeongtaek-si and Seongnam-si. Number of shopping building for this study is 30 and of stair passage leading light inspected by two lights in each shopping building is 60. The result of this study is that the type of installed leading lights is LED(77%), and 60% of leading lights has problem such as no cleaning, scratch and discoloration, etc. The height of installed leading lights meets the fire law which is less than 1m from the floor. Visible condition of leading lights is good except some leading lights which have a little visible problem due to banner advertisement. 37% of standby power has flickered and went out. 93% of total leading lights meets the fire law which is more than 1lux from 0.5m distance, but cold cathode fluorescent lamps(CCFLs) have the problem which not meets proper brightness level based on fire law. In additional measurement result, zero lux of leading lights is 32%(from 1m distance), 68%(from 1.5m distance) and 98%(from 2m distance). Leading light is very important facility because it is eyes and guide when emergency. Therefore, proper fire facility operating function inspection and total detailed inspection are important to keep the good condition of leading light except simple visual check, and also improvement in law system of type approval, fire construction inspection and illumination level will be needed.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.550-557
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• 2005

Because each building is built in different time, there exists different equipment to meet the need for each age. Before the announcement of "Community Management Regulation", the old communities usually suffer the problem of lower requirement and living quality. This may bring some security problem that we should face. In this research, we construct "Building Administration System" to provide users a tool to perform a standard operation procedure in community management. This powerful tool will also help manager to effectively handle important tasks in property administrating by reducing unnecessary documentation. In the current regulation, all community committee members shall be voted each year. This will seriously affect the cumulative of management knowledge and cause a worse efficiency. In this research, we use Object Oriented concept and Visual Modeling techniques to combine with Interbase, ER/Studio, and Delphi to develop this management system for Building Property. Through the help of current computing technology, we can solve the problem that can not be inherited and the storing of the huge amount of data. In this system, we develop the modules such as Basic Data Module, Administrative Expense Calculation, Receipt Print, and Inquiring for Inheritance. In this system, we have integrated all houses, parking lots, and public equipments in it. Manager will only need to handle some basic accounting data; the system will automatically handle the rest. Through the help of this system, the community management staff can be easily accomplished and put more manpower on some needed aspect to improve the living quality.

• Journal of architectural history
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• v.24 no.4
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• pp.19-28
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• 2015

This study examines the Singapore public housing supplied by Singapore Improvement Trust (SIT) in the 1950s. Focused on the Princess Elizabeth estate and Princess estate of Queenstown, this study surveys their construction backgrounds, site plans, unit plans, architectural designs and meanings. The Princess Elizabeth estate was the model estate for workmen's flats. This estate showed mixed blocks of flats arranged around a large quadrangled open space for children. The Princess estate was a neighborhood of Queenstown, Singapore's the first new town. At this Estate, there were some new architectural occurrences departing from the Tiong Bahru Estate. Those are the appearance of high-rise typology, and the increased specificity in the functions of open spaces. Thus the open space became to get hierarchy, and divided an estate to small neighborhood units. For the SIT, open space is synonymous with the improvement of urban environment. Through the purposeful creation of open space, the SIT intended to solve the problem of sanitation and to make a neighborhood unit which can be pleasant place for regional community.

• Journal of the Korea Concrete Institute
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• v.11 no.6
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• pp.57-67
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• 1999

Optimization scheme is presented for the design of precast prestressed double-tee beams used as slabs in the parking or market structures. The objective considered is defined by a function that minimizes the hight of the double-tee beam, including the prefabricated element and the concrete topping poured in a second phase. The Sequential Quadratic Programming method is adopted to solve the problem. As an example 12 double-tee beams are designed with the design loads of the current design code of our country. The results from optimization process show that at least 29cm less in overall height than that designed by PCI design handbook. The section determined from the optimization process was refined for practical considerations. A MathCad 7.0 Pro Spreadsheet was prepared to verify all ACI requirements for flexure, shear and deflections. Flexural tests are performed on four full-scale 12.5m prototype models and show that all the specimens are fully comply the flexural strength requirements as specified by ACI 318-95. The present optimization scheme can be used for wider application of the design of precast prestressed double-tee beams with different materials and configurations particularly for in a large scale or for important designs.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1217-1224
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• 2010

These days, the maintenance of closed waste landfill come to the fore social problem such as legal maintenance period, after closed maintenance deposits, stability evaluation guides and environmental survey for closed landfill management. Therefore the many non-sanitary closed waste landfill has been removed by selection and transfer to sanitary landfill and incineration. When the remove the non-sanitary landfill, the pollution level of bottom soil was investigated by related government law. In this case study, the soil contamination survey was performed to evaluate the pollution level of non-sanitary closed landfill bottom soil. Based on this study, the pollution level of studied non-sanitary landfill bottom soil was content with related government law for third area(factory, parking lot, gas station, road, railroad use etc.).

• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.221-228
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• 1998

The effect of air drag was researched when a low-earth orbit spacecraft using power-limited thruster rendezvoused another low-earth orbit spacecraft. The air density was assumed to decrease exponentially. The radius of parking orbit was 6655.935km and that of target orbit was 7321.529km. From the trajectories of active vehicles, the fuelconsumption and the magnitude of thrust acceleration, we could conclude that the effect of air drag had to be considered in fuel optimal rendezvous problem between low-earth orbit spacecrafts. In multiple-revolution rendezvous case, the air drag was more effective.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.3
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• pp.95-102
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• 2018

The objective of this research is to explore the diverse challenges faced by the customer as well transport providers through the selected modes of transportation of the second most populous country in the world - India. Two separate well-structured questionnaires administered to garner the opinions on different challenges. A random sample of 100 equally selected from the customers of 3 modes of transportation along with 30 transport providers. The collected data was analyzed in Microsoft Excel and R Studio platforms using Percentile Rank Tool and R Programming Language for Chi-square test respectively. Traffic congestion coupled with parking is the major problem in case of roadways while Safety and cleanliness in railways are the first amongst the problems to reckon with. High fares and lack of trained employees are the biggest challenges faced by aviation industry. The research is concentrated only in the states of Andhra Pradesh and Telangana in India with most widely used three modes of transportation viz., Road, Rail and Airways. This research paper is first of its kind which has collected the opinions of both customers as well transport providers on the problems faced. This research proffers information about the challenges faced by the customers which there will be an enormous possibility to review their strategies and plans.