• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.45-53
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• 2004

An experimental study was carried out to obtain the fundamental data about the effects of radicals induced injection on premixture combustion. A constant volume combustor divided to the sub-chamber and the main chamber was used. The volume of the sub-chamber is set up to occupy less than 1.5％ of that of whole combustion chamber. Radial twelve narrow passage holes are arranged between the main chamber and the sub-chamber. The products including radicals generated by spark ignition in the sub-chamber will derive the simultaneous multi-point ignition in the main chamber. While the equivalence ratio of pre-mixture in the main chamber and the sub-chamber is uniform. We have examined the effects of the sub-chamber volume, the diameter of passage hole, and the equivalence ratio on the combustion characteristics by means of burning pressure measurement and flame visualization. In the case of radical ignition method(RI), the overall turning time including the ignition delay became very short and the maximum burning pressure was slightly increased in comparison with those of the conventional spark ignition method(SI), that is, single chamber combustion without the sub-chamber. The combustible lean limit by RI method is extended to more ER=0.25 than that by SI method. Therefore the decrease of every emission including NOx and the improvement of fuel consumption is anticipated due to lean burn.

• Korean Institute of Interior Design Journal
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• no.21
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• pp.154-165
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• 1999

It is characteristic that houses designed by Adolf Loos show commonly a contradictory aspect between the exterior and interior. The exteriors of the houses are simple and on the other hand the interiors are affluent to the greatest degree. At that time, a stylized gorgeous decoration of the inner space had been prevailed in general among the historicism and Vienna Secession people, and such an inner spatial conception as by Loos must have brought a turning point for the development of a new inner spatial conception which can by itself be called revolutionary. This study is gong to clarify the fact that Loos has been in full consideration of the emotional side basically for the human being in the conception of inner space, by complementing the respect that his conception of the inner spatial composition, concentrating purity, comfort and classicalism on the furniture. Despite the independency of the Loos furniture is near copying, different from existing creative conception, it can be meaningful in respect that it creates out a rather accustomed and still a new space thought adding a little transformation to the existing classical furniture. So this study is going to re-establish the characteristics of the Loos furniture which work as the greatest impact in the composition of affluent inner space, the prototypical characteristics of that furniture, and the basical thinking system of Loos which can be found out in a little transformatiov.

• Journal of Korean Library and Information Science Society
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• v.27
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• pp.97-136
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• 1997

Korea has good mutual relations with Russia and China in many fields, not just in science and technology, but also in trade. That is, it stands on a point of time in which an epoch-making turning point for mutual interests could be realized depending on how to join Russia's high technology with Korea's industrial technology with capital, or how to connect Korean -Chinese mutual concern and each other's advanced technology. The purpose of this study is to present scientific and technical information management policy for efficient su n.0, pport for technical cooperation with Russia and China. Bearing this purpose in mind, the concept of technical cooperation along with scientific and technical information management policy was closely examined. The correlation between the progress of technology and the type of scientific and technical information was examined, while the flow of scientific and technical information accompanying technical cooperation was studied. The methodology adopted for this study includes document research, empirical analysis and fact-finding survey. For document research, the writer analyzed the contents of scientific and technical information managing operations and the types of information to be utilized in the course of technical cooperation by examining domestic and foreign documents on international technical cooperation. For empirical analysis, the contents of actual results of scientific and technical information managing operations for technical cooperation with Russia and China were put in order and analyzed, while contents of survey conducted by organizations related to these countries for technical cooperation were synthesized and examined for fact -finding survey.

• Smart Structures and Systems
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• v.8 no.1
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• pp.39-52
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• 2011

We are developing a biomimetic robot based on the Sea Lamprey. The robot consists of a cylindrical electronics bay propelled by an undulatory body axis. Shape memory alloy (SMA) actuators generate propagating flexion waves in five undulatory segments of a polyurethane strip. The behavior of the robot is controlled by an electronic nervous system (ENS) composed of networks of discrete-time map-based neurons and synapses that execute on a digital signal processing chip. Motor neuron action potentials gate power transistors that apply current to the SMA actuators. The ENS consists of a set of segmental central pattern generators (CPGs), modulated by layered command and coordinating neuron networks, that integrate input from exteroceptive sensors including a compass, accelerometers, inclinometers and a short baseline sonar array (SBA). The CPGs instantiate the 3-element hemi-segmental network model established from physiological studies. Anterior and posterior propagating pathways between CPGs mediate intersegmental coordination to generate flexion waves for forward and backward swimming. The command network mediates layered exteroceptive reflexes for homing, primary orientation, and impediment compensation. The SBA allows homing on a sonar beacon by indicating deviations in azimuth and inclination. Inclinometers actuate a bending segment between the hull and undulator to allow climb and dive. Accelerometers can distinguish collisions from impediment to allow compensatory reflexes. Modulatory commands mediate speed control and turning. A SBA communications interface is being developed to allow supervised reactive autonomy.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.3
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• pp.266-273
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• 2012

In this paper, the new open fault detection and tolerant operation method for 3 phase PWM rectifier is proposed. When open fault occurred on the inverter switches of 3 Phase PWM rectifier, the DC link voltage ripple is increased because the input current of the faulty phase is distorted. In this case, the quality of electric power would decrease, and the life time of DC link capacitor is decreased. The open fault is detected by a simple MRAS(Model Reference Adaptive System) without additional hardware sensors, and the tolerant operation carried out by turning on the opposite switch of the faulty switch without any redundancy. By the proposed method, the faulty phase input current can be controlled, so that 3-phase input current is balanced relatively under the faulty condition and the voltage ripple of DC link output is reduced. The validity of the proposed technique is proved on the 6kW 3-phase PWM rectifier system by simulation and experiment.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.2
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• pp.154-161
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• 2014

Naval ships have hull appendages which are more exposed to the outside because of its small block coefficient compared with commercial ships. These exposed hull appendages like skeg, strut and shaft line affect the maneuverability of a ship. The effect of hull appendages has considered at initial design stage to estimate more accurate maneuverability. In this paper, sensitivity analysis is used to analyze the effect on maneuverability by hull appendages. 3 DOF maneuvering equations based on Mathematical Modelling Group (MMG) model are used and propeller & rudder model are modified to reflect the characteristics of twin propeller & twin rudder. Numerical maneuvering simulations (Turning test, Zig-zag test) for benchmark naval vessel, David Taylor Model Basin (DTMB) 5415 are performed. In every simulation, it is calculated that stability indices and maneuverability characteristics (Tactical Dia., Advance, 1st Overshoot, Time of complete cycle) with respect to the parameters (area times lift coefficient slope, attachment location) of hull appendages. As a result, two regression formulas are established. One is the relation of maneuverability characteristics and stability indices and the other is the relation of stability indices and hull appendages.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.367-373
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• 2014

Surface texturing is a machining process on the surface to give engineering functions. The representative process of the surface texturing is lotus effect to give hydrophobic property by the lithography and chemical etching, which is the bio mimic from the nature. Surface texturing can be manufactured by a lot of processes, in particular using mechanical method such as a precise diamond turning, grinding, rolling, embossing, vibrorolling, and abrasive jet machining (AJM). Among them, the grinding process is notable in terms of the wide range of texturing area and fast processing time. The patterning by grinding is done by the grooved grinding wheel on the work piece. In this case, the pattern shape is determined by the grinding conditions as well as the wheel dressing conditions. In this paper, experimental study on the pattern shapes were done and provide the feasibility in use for the large area patterning.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.4
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• pp.132-137
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• 2007

A point-wise car-like robot moving in the plane changes its direction with a constraint on turning curvature. In this paper, we consider the problem of computing a shortest path of bounded curvature between a prescribed initial configuration (position and orientation) and a polygonal goal, and propose a new geometric proof showing that the shortest path is either of type CC or CS (or their substring), where C specifies a non-degenerate circular arc and S specifies a non-degenerate straight line segment. Based on the geometric property of the shortest path, the shortest path from a configuration to a polygonal goal can be computed in linear time.

• Journal of Korea Multimedia Society
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• v.25 no.3
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• pp.546-557
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• 2022

Recently, the demand to interpret image data with artificial intelligence in various fields is rapidly increasing. Object recognition and detection techniques using deep learning are mainly used, and video integration analysis to determine unstructured object recognition is a particularly important problem. In the case of natural disasters or social disasters, there is a limit to the object recognition structure alone because it has an unstructured shape. In this paper, we propose intelligent video integration analysis system that can recognize unstructured objects based on video turning point and object detection. We also introduce a method to apply and evaluate object recognition using virtual augmented images from 2D to 3D through GAN.

• Journal of Distribution Science
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• v.21 no.1
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• pp.95-105
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• 2023

Purpose: This study aims to explore the distribution of work-life integration against COVID-19 and its Implications by analyzing remote work in Switzerland. Research design, data and methodology: The study performed literature review and descriptive analyses using various data such as perception surveys, statistics, and related documents. Results: The infectious disease was a turning point for many people in Switzerland by changing where and how people want to live. Since the COVID-19 crisis demonstrated that disease could be spread by proximity, negative perception about urban areas expanded, and rural areas are increasingly preferred due to fresh and clean air and a more ecological lifestyle. In addition, increased remote work, a change brought about by COVID-19, has subsequently led to changes in household habits and needs. Distance from work is no longer an important factor when someone chooses where to live. A trend is now emerging where households wanting to improve the quality of life leave the city center and move to the suburbs. Conclusions: Paradoxically, such trend accelerated by the COVID-19 crisis has an unintendedly positive impact on the distribution of work-life integration across society while providing more flexibility in terms of place and time management and lowering the burden on roads and infrastructure.