• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1752-1757
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• 2011

In a traditional phased array radar, closely spaced antenna elements transmit a scaled version of single waveform to maximize the signal energy. On the contrary, a multiple-input multiple-output (MIMO) radar consists of widely separated antennas and transmits an arbitrary waveform from each antenna element. These waveforms and spatial diversity enable superior capabilities compared with phased array radar. At high signal-to-noise ratio (SNR), the detection performance of the MIMO radar is better than the phased array radar due to the diversity gains. However, the phased array radar outperforms the MIMO radar at low SNR, due to the energy maximization. In this paper, we investigate the compromised scheme between the MIMO radar and the phased array radar. Employing the MIMO radar equipped with phased array elements, the compromised scheme achieves both array gain and diversity gain. Also, we compare the performance degradation when the steering direction is incorrect.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.143-150
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• 2007

A meander slot antenna with open-end fed by a microstrip line which can be used at 400 MHz ISM band is newly proposed. The main difference between the proposed slot antenna and the previous slot antenna is the introduction of the open-end to miniaturize the previous meander slot antenna in the space restricted within narrow limit. In order to check the validity of the proposed antenna, the resonant frequency and radiation pattern of the proposed antenna have been simulated and examined. Good agreements between simulated results and measured results have been observed.

• The Research Journal of the Costume Culture
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• v.25 no.6
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• pp.847-861
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• 2017

As the excavated costumes from the unknown tomb of the Joseon Dynasty were unearthed, estimating the age of the costumes became very important. This research investigat and estimates the age of the excavated costumes from Couple's Tomb for Lee General in Seosan, Chung-nam. By inspecting and analyzing the costumes, the features can be compared with other similar costumes that have been excavated from other tombs. The result of this study is as follows: First, the period with dopo, cheol-rik, jungchimak, and baji for females among the relics of General Lee can be estimated. For dopo, there are morphometric features such as the shape of moo; for cheol-rik, there is a ratio of top and bottom; for jungchimak, there is a ratio of width of arm and skit and a ratio of side tim, total length, etc. By comparing relics of same period, it can be estimated to be from the late 16 century around the Japanese invasion of Korea to the early 17 century. Second, the period with jangui and jeogori among the relics of Couple's Tomb for General Lee can be estimated. By comparing jangui with the arm and width of sleeves, and by comparing jeogori and the shape of the collar, arm, length, etc., with other relics identical to the period, it can be estimated to be from the late 16 century around the Japanese invasion of Korea, which is a similar date to the one with the husband to the early 17 century.

• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.167-173
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• 2010

In order to design small printed antenna restricted within narrow area of $30mm{\times}8mm$ for the Zigbee module and improve its return loss, meander slot antenna with a floating conductor as the parastic element has been proposed. The resonant frequency and bandwidth(VSWR${\leq}$2) of the antenna designed and fabricated in the present study is about 2.44GHz and 113MHz respectively. The radiation pattern is almost similar to that of dipole antenna within the operation frequency range. Also the radiation efficiency and gain of the proposed antenna is more than 60% and 2.7dBi respectively. It has been observed that the characteristics the proposed antenna mentioned above satisfy the specification required of the Zigbee application. In order to validate the proposed antenna, some simulated and measured results are presented and compared.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.441-455
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• 1997

An agent system is comsisted of agents that have the following properties: autonomy, scial ability, reactivity, pro-activeness.It provides a good enbironment to an end-user.Therefore, an end-user can feel more natural and comfortable in using a computer system.However, a system develper will have difficulty because he(or she) has to follow the funditons and the speiciffcation which are generally required for an agent system.Moreover, it is hard to ues resoures mutually and share information between agent systems that are solely developed without satisfying the standardization .In this paper, we describe the requirments for and agent development tools(ADT).We also introduce the ADT that is developed to efficiently resolve the problems occurred in develping an agent system.The main properties of the ADT are:ether expert or non-expert can easily intervace an appli-cation to existiong agent systems and effectively manage the resoures that are related to the agent systems.There-fore , one can easily expand agent system and achieve high quality of services with our ADT.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.644-651
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• 1997

In the water purification plant, chemicals are injected for quick purification of raw water. It is clear that the amount of chemicals intrinsically depends on water quality such as turbidity, temperature, pH and alkalinity. However, the process of chemical reaction to improve water quality (e.g., turbidity) by chemicals is not yet fully clarified nor quantified. The feedback signal in the process of coagulant dosage, which should be measured (through the sensor of the plant) to compute the appropriate amount of chemicals, is also not available. Most traditional methods focus on judging the conditions of purifying reaction and determine the amounts of chemicals through manual operation of field experts using Jar-test data. In this paper, a systematic control strategy is proposed to derive the optimum dosage of coagulant, PAC(Polymerized Aluminium Chloride), using Jar-test results. A neural network model is developed for coagulant dosing and purifying process by means of six input variables (turbidity, temperature, pH, alkalinity of raw water, PAC feed rate, turbidity in flocculation) and one output variable, while considering the relationships to the reaction of coagulation and flocculation. The model is utilized to derive the optimum coagulant dosage (in the sense of minimizing turbidity of water in flocculator). The ability of the proposed control scheme validated through the field test has proved to be of considerable practical value.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.795-802
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• 2018

This study describes the semantic theoretic interpretation through the extensive use of semantic metaphors for intensive web interface with information and the metaphoric value of metaphors for interface design. Common factors that influence web design are empirical establishment and verification for generating web symbols and these are have important elemental perspectives that are used to assess the usefulness and key elements of the site. In addition, the structure of the screen has begun to change dynamically from the application of web technological functions, and the media functions have become important to make web standards when implementing visual structuring from the perspective of semiotic. Instead of using a technical expression approach to examine semiotic, a semiotic approach is applied to create aesthetic codes through the human-computer interface in terms of semiotic in a variety of natural and universal fields. Based on this, it is used as means of communication to convey the intended meaning to users so as to highlight the importance of the usability issues and metaphors user interface.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.426-435
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• 2011

In this study, PM emission factors for commercial meat cooking were developed by the experiment using the similar restaurant model. The commercial material types of meat cooking were beef, pork and duck. And meat cooking materials were classified with marinated and raw cooking methods. The marinated and raw cooking methods were flat griddle (LPG) and under fired charbroiling grill. As a results, $PM_{10}$ emission factors for underfired pork cooking was estimated as 7.39 g/kg-meat which was the highest value in this study. The emission factors of under fired charbroiling grill method were higher than that of flat griddle method regardless of meat cooking material types and marinated meat. The particle size distribution of meat cooking was 0.23~5 ${\mu}m$ and median diameter was 2~2.5 ${\mu}m$.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.40-46
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• 2015

Stoichiometric combustion engine with Three-way catalyst had an advantage that can reduce the harmful emissions effectively. Fuel equivalence ratio controlled from engine is very important because Fuel equivalence ratio with high conversion efficiency was narrow. This study analyzed the conversion efficiency under whole range of operating area for to evaluate the performance of three-way catalyst. In order to identify the Optimum conversion efficiency, the conversion efficiency due to change the control value of fuel equivalence ratio was investigated. The result show that conversion efficiency of emissions(more than 95%) has discovered by means of fuel equivalence ratio control at each test condition. As engine power increases, optimal fuel equivalence ratio tended to increase linearly under operating conditions of similar exhaust gas temperature.

• Korean Journal of Medicinal Crop Science
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• v.18 no.3
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• pp.151-156
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• 2010

Obesity has become one of the main public health problems. Saussurea lappa (Asteraceae), syn Aucklandia lappa and Saussurea costus, is a well-known herbal medicine that has been used for treating various ailments, such as inflammatory and gastrointestinal diseases. The present study examined the anti-obesity effect of S. lappa extract (SLE) in 3T3-L1 adipocytes and high fat diet (HFD)-induced obese mouse model. SLE significantly inhibited the differentiation from preadipocytes to adipocytes of cultured 3T3-L1 in dose-dependent manner. In addition, SLE significantly decreased the body weight gain and the food efficiency ratio of mice fed HFD during 9 weeks. Further study must be performed for the pharmacological mechanism and safety of SLE as well as the identification of active compound in SLE. Our results revealed that S. lappa suppresses the adipogenesis in cultured cells and the obesity in rodent models. Therefore, S. lappa may be useful toward the development of new potent anti-obesity drugs.