• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.5
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• pp.321-328
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• 2015

In recent years, there has been an increasing demand to apply the new IACS(International Association of Classification Societies) standards for ice and polar-classed ships. For ice-class vessel propulsion system, the ice impact torque design criterion is defined as a periodic harmonic function in relation to the number of the propeller blades. However, irregular or transient ice impact torque is assumed to occur likely in actual circumstances rather than these periodic loadings. In this paper, the reliability and torsional vibration characteristics of a comparatively large six-cylinder marine diesel engine for propulsion shafting system was examined and reviewed in accordance with current regulations. In this particular, the transient ice impact torque and excessive vibratory torque originating from diesel engine were interpreted and the resonant points identified through theoretical analysis. Several floating ice impacts were carried out to evaluate torque responses using the calculation method of classification rule requirement. The Newmark method was used for the transient response analysis of the whole system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.12
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• pp.1-9
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• 2009

A full adders is an important component in applications of digital signal processors and microprocessors. Thus it is imperative to improve the power dissipation and operating speed for designing a full adder. We propose a new adder with modified version of conventional static CMOS and pass transistor logic. The carry-out generation circuit of the proposed full adder is different from the conventional XOR-XNOR structure. The output Cout of module III is generated from input A, B and Cin directly without passing through module I as in conventional structure. Thus output Cout is faster by reducing operation step. The proposed module III uses the static CMOS logic style, which results full-swing operation and good driving capability. The proposed 1bit full adder has the advantages over the conventional static CMOS, CPL, TGA, TFA, HPSC, 14T, and TSAC logic. The delay time is improved by 4.3% comparing to the best value known. PDP(power delay product) is improved by 9.8% comparing to the best value. Simulation has been carried out using a $0.18{\mu}m$ CMOS design rule for simulation purposes. The physical design has been verified using HSPICE.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.336-341
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• 2013

In this paper, the design concept of a low-temperature vacuum blackbody was described, and thermophysical model of the blackbody was numerically evaluated. Also the working performance of low-temperature vacuum blackbody was evaluated using infrared camera system. The blackbody system was constructed to operate under high-vacuum conditions ($2.67{\times}10^{-2}$ Pa) to reduce temperature uncertainty, which is caused by vapor condensation at low temperatures usually below 273 K. In addition, both heat sink and heat shield including cold shield were installed around radiator to prevent heat loss from the blackbody. Simplified mathematical model of blackbody radiator was analyzed using modified Stefan-Boltzmann's rule. The infrared radiant performance of the blackbody was evaluated using infrared camera. Based on the results of measurements, and simulation, temperature stability of the low-temperature vacuum blackbody demonstrated that the blackbody system can serve as a highly stable reference source for the calibration of an infrared optical system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.5
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• pp.38-48
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• 2010

Adverse weather (e.g. strong winds, snow and ice) will probably appear as a more serious and frequent threat to road traffic than in clear climate. Another consequence of climate change with a natural disastrous on road traffic is respond to traffic accident more the large and high-rise bridge zone, tunnel zone, inclined plane zone and de-icing zone than any other zone, which in turn calls for continuous adaption of monitoring procedures. Accident mitigating measures against this accident category may consist of intense winter maintenance, the use of road weather information systems for data collection and early warnings, road surveillance and traffic control. While hazard from reduced road friction due to snow and ice may be eliminated by snow removal and de-icing measures, the effect of strong winds on road traffic are not easily avoided. The purpose of the study described here, was to design of amber information the relationship between traffic safety, weather, user information on road weather and driving conditions in local-scale Geographic. The most applications are the optimization of the amber information definition, improvements to road surveillance, road weather monitoring and improved accuracy of user information delivery. Also, statistics on wind gust, surface condition, vehicle category and other relevant parameters for wind induced accidents provide basis for traffic control, early warning policies and driver education for improved road safety at bad weather-exposed locations.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.108-116
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• 2002

This paper presents the measurements and evaluation of voltage waveforms due to human electrostatic discharge(ESD). The principle of operation and design rule of a new device for measuring the ESD fast transient voltages with very fast rise time were described. Peak values and rise time of ESD voltages derived from a charged human body under a variety of experimental conditions were examined. The frequency bandwidth of the proposed voltage measuring system ranges from DC to 400[㎒]. The ESD voltage waveform is nearly equal to the ESD current waveform and the peak amplitude of ESD current waveform is roughly proportional to the ESD voltage in each experimental conditions. A rapid approach results in a discharge voltage with a faster initial rise time than for a slow approach. The voltages caused by direct finger ESDs have an initial slope with a relatively long, 10∼30[ns] rise time, but the amplitude is small. On the other hand, the voltages caused by direct hand/metal ESDs have a steep initial s1ope with 1 ∼3[ns] rise time, but an initial spike is very big. As a consequence, it was found that the ESD voltage and current waveforms strongly depend on the approach speed and material of intruder. These measurement results would be useful to design the ESD protective devices.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.327-330
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• 2008

Resently as ubiquitous environment rapidly emerges due to the development of network and information communication technology, ubiquitous computing is being noticed as a technology that will take the lead in information technology industry of the future. For the realization of this Ubiquitous Service requires some technique such as situations of environment and recognition of locations by the Sensor Network, then sensor data have to be transferred to an application service after processes. Also the creation rule of registration and search of the event is necessary because the USN sensor data must be possible to specific the multi condition of event which relates on using time. And for using a numerous sensor data provision service, service provider can publish its service in standardized registry for users to search and use the service registry. Currently there is the web service for a WS-Eventing and a UDDI with standard, but the event and the service registry is unnecessary or there is a portion which is insufficient. In this paper, I design and implementated standardzation of event definition for USN application service and service registry structure, standard API.

• Archives of design research
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• v.12 no.4
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• pp.182-190
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• 1999

There has been the rapid change of paradigm with the overflow of terms related to computers such as information, digital, cyber, virtual world and the change of time concept on the ground that it is common to change the world into virtual time. This study is about cybercharacters working in air-broadcasting with rapidly-developing internet, The cybercharacters including 3D animation developed from 2D animation are know to be manufactured with use of electronic mediun and computers and to exist in electronics. Though the emergence of the cybercharacters has a lot of gflnetic roots according to their objectives, they have in common that they are made by 3D graphics and they work in the virtual space, The great traits of the cybercharaters lie in the extension of interfacial function and ecological growth. In the cyberspace the interface, the meeting point between a computer and its users is the most important, The cybercharacters as medium providing new ruman interface become effective with growing interest in virtual reality, The cybercharacters also keep the ecological traits, They can also bring about added value with infusion of image and development of the network, These cybercharacters can also play the important parts in the continually developing cyberspace, The successful birth of the cybercharacter are based on, the technological power. assistance of fund and the ctrltural background, The information-entertainment of the cybercharacters functions well with the accompinimene of these three things, The cybercharacters can make a subject which keeps single issue as a central point of the virtual realty, The cybercharacters can also be connected with equity of "Korean knowledge information society" in the cultural rule of the internet and sociocul tural identity, identity.

• The KIPS Transactions:PartB
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• v.15B no.1
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• pp.37-44
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• 2008

With the growing proliferation of mobile computing devices, several industrial and academic research groups have a vigorous studying to remote control for various appliances with mobile devices such as Notebooks, PDAs, and Smartphones in home network environments. We can utilize the good points of mobile devices such as portability and usability so that we can remote control and manage the mobile devices connected on home networks anytime, anywhere. However, mobile devices use different languages. Therefore, they cause some problems because their interfaces and the methods of operation are different each other. To solve these problems, there are two consideration. First, we may be solved development of the user interface and difficulty of maintenance in order to control various heterogeneous devices. Second, we may provide the user interface which is dynamically adapting user's preferences and device characteristics. To satisfy these considerations, we describe the design of an adaptive user interface for home network environments using the UIML (User Interface Markup Language) based on XML (eXtensible Markup Language) and the profile information of the user and device. Therefore, we present several implementation examples that show how the framework can form the basis of prototypical applications.

• Journal of KIISE:Information Networking
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• v.33 no.6
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• pp.407-419
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• 2006

As substituting IPv6 network for all IPv4 network in a short time seems unattainable due to high cost and technical limitation, IPv4 and IPv6 are expected to coexist for a certain period of time. Under the co]existing environment of IPv4 and IPv6, interworking brings a number of extra security considerations even if it may have no security problem for each protocol respectively. Thus, the analysis and solutions for those various attacks toward IPv4/IPv6 interworking-related security are inevitably required for the sake of effective transition and settlement to IPv6. In this paper we carried out a proper rule of packet filtering for IPv6-in-IPv4 tunneling interworking environment to protect the IPv4/IPv6 interworking-related security attacks. Design and implementation of the packet filtering system suitable for IPv4/IPv6 tunneling environment in the form of Linux netfilter and ip6tables are also shown. Thru this study, the packet filtering system was found operating correctly ill the tunneling mechanism.

• Journal of KIISE
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• v.42 no.8
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• pp.998-1009
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• 2015

In recent years, there has been a growing interest in RDFS Inference to build a rich knowledge base. However, it is difficult to improve the inference performance with large data by using a single machine. Therefore, researchers are investigating the development of a RDFS inference engine for a distributed computing environment. However, the existing inference engines cannot process data in real-time, are difficult to implement, and are vulnerable to repetitive tasks. In order to overcome these problems, we propose a method to construct an in-memory distributed inference engine that uses a parallel graph structure. In general, the ontology based on a triple structure possesses a graph structure. Thus, it is intuitive to design a graph structure-based inference engine. Moreover, the RDFS inference rule can be implemented by utilizing the operator of the graph structure, and we can thus design the inference engine according to the graph structure, and not the structure of the data table. In this study, we evaluate the proposed inference engine by using the LUBM1000 and LUBM3000 data to test the speed of the inference. The results of our experiment indicate that the proposed in-memory distributed inference engine achieved a performance of about 10 times faster than an in-storage inference engine.