• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.427-438
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• 1998

The bit error rate(BER) performance of Trellis Coded QPSK signal in the presence of cochannel interference (CCI) and Rician fading is investigated. The trellis coded QPSK system adopts Maximum Ratio Combining (MRC) diversity reception and Reed-Solomon code to enhance system performance. Using the derived error probability equation, the error performance of trellis coded QPSK system has been evaluated and shown in figures to discuss as a function of signal power to noise power ratio (SNR), signal power to interference power ratio(SIR), direct to indirect signal power ratio ($K_R$), the number of diversity branch (M), the frame length of Reed-Solomon code (n), the number of error correction symbol (t), and the number of state of trellis encoder. From the results, we know that proposed system is affected by cochannel interference and fading in microcell environment. Also, BER performance of Trellis Coded QPSK system can be improved as increasing either the power of desired signal or the value of SIR. And the BER floor in microcellular system is caused by the cochannel interference and it occurs at high BER when SIR is low. And Reed-Solomon code (n=15, t=2) is more effective to restrain the affection of CCI and fading than MRC diversity reception (M=2).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10C
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• pp.995-1006
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• 2003

It is well know that in the wireless communication systems the transmitted signals can suffer from multipath fading due to the wave propagation characteristics and the obstacles over the paths, resulting in serious reduction in the power of the received signals. However, it is possible to take advantage of the inherent diversity imposed in the multipath reception if the underlying channel can be properly estimated. One of the diversity reception methods in this case is Rake processing. In this paper we study the Rake receivers for the direct-sequence spread-spectrum communication systems utilizing PN (pseudo noise) sequences to achieve spread spectrum. A conventional Rake receiver can use the finite-duration impulse (FIR) filter followed by the PN sequence demodulator, where the FIR filter coefficients are the reverse-ordered complex conjugate values of the fading channel impulse response estimates. Here, we propose a new Rake processing method by replacing the aforementioned PN code sequence with a new set of optimum demodulator coefficients. More specifically, the concept of the new optimum Rake processing is first introduced and then the optimum demodulator coefficients are theoretically derived. The performance obtained using the new optimum Rake processing is also calculated. The analytical results are verified by computer simulation. As a result, it is shown that the new optimum Rake processing method improves the MSE performance more than 10 dB over the conventional one using the fixed PN sequence demodulator. It is also shown that the new optimum Rake processing method improves the MSE performance about 10 dB over the Adaptive Correlator that performs the combining of the multipath components and PN demodulation concurrently. And finally, the MSE performance of the optimum Rake demodulator is very close to the MSE performance of OPSK demodulator under the AWGN channel.

• Journal of Korean Theatre Studies Association
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• no.40
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• pp.345-400
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• 2010

Konstantin S. Stanislawski(1863-1938) is one of the great acting-teachers and directors. Especially his 'System' influences this day like his period so many actors and directors in the world. In Korea, Stanislawski was introduced at first in 1920's by Kim, Woojin, dramatist. After that time, his system was influenced fast everyone in the korean drama world. As a result, so many translations of his books and researches of his system are done until nowadays, but it is not perfect for the correct understanding of Stanislawski and his system. It seems to be several causes in this misunderstanding. And the purpose of this thesis is at first to observe historically the results of researches and translations on Stanislawski and his system in Korea and then to bring it in order according to characteristics. In this thesis are the process of reception observed dividing 4 periods. The first period is from the beginning to the liberation in 1945. The second is to 1980's and the next is to the year 2000. And the final period is from that time to the present time. As a result are several characteristics found as followings: 1) translations of Stanislawski's first book like other books, for example, Building a Character and Creating a Role, an Actor Prepares, are fast all secondhand translations, that means, man translated it not from russian direct but japanese or english. It caused man to misusing of terms and then misunderstanding on the system. 2) the researches on Stanislawski in are fast all concentrated on the book, an Actor Prepares, so this leads man to regard it as his whole acting system. On the other hand, thesisses which deal with his last and final acting technique, "the Method of the physical Action" are relatively not so much. As though man knows the last, man used to think that the system is developed systematically from the psychological technique to the physical action or the method of the physical action is only the way to understand of stanislawski's acting method. The psychological method and the physical are not the divided, different acting technique, but pairs which are applied to different objects, that is, the actor himself and the role in texts. 3) the political aspects are not considered especially under the situation of Stalin's social realism. This lack of the political context having relation with the system acts as a obstacle upon understanding the correct, whole his system. But so many thesises on this theme in other countries are so vivacious. For example, man can find subjects like "Stanislawski and Meyerhold", "means of Stanislawski's method for theatres in the social context". There are also many interesting Questions related to the physical action. That is, is the physical action the final acting technique or the materialistic dialectical device to survive under the Stalin's rule? Is there some interrelations between stanislawski's physical action and Meyerhold's biomechanics? In conclusion, the researches on Stanislwski and his system are not enough to understand correctly and overcome the system. We have to start the research again at least from the direct translation his books written russian in order to apply it in a new times.

• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.101-107
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• 2003

In this study, we provide a single element log-periodic antenna that the feeding networks and array structures are aperture coupled and series dipole array type. We made the antenna for direct receiving the Moogoongwha satellite broadcasting signal. The transmission power was able to feed the patch dipole in series due to lay perpendicularly 8 series patch dipole on tapered slot. The patch dipole radiation pattern which fed in series power, make the main beam direction up $37^{\circ}{\sim}42^{\circ}$ within the BS/CS bandwidth. The main beam gain was measured 9.31~11.03 dBi. Using 32 elements to array the elements properly, we acquire $4{\times}8$ array structure on limited PCB board. As a result, it has been found that the new planar DBS antenna structure have high gain over 10dBi and acceptable elevation angle over 42 degree, and we can apply this result to commercial DBS reception antenna manufacturing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.123-130
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• 1996

Experiments were conducted to effect of seeding rates and growth regulator (KIM-112) application on lodging resistance and yield in direct seeding on flooded paddy surface. The number of seedlings per $m^2$ were ranged from 61 to 143, and seedling ratios were from 71.7 to 76.1％. The culm length was increased with the higher seeding rates. The culm length was significantly shortened by KIM-112 application, and the shortened effect of internodes were various with application times. The leaf angles with the culm and top leaves were errected and position of light reception by KIM-112 application, also the weight of culm base was increased. The bending moment at breaking of culm and culm diameter were decreased according to the higher seeding rates. The number of panicles per $m^2$ were increased according to the higher seeding rates. The ripened grain rate and 1, 000 grains weight became higher than the untreated control.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5C
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• pp.555-560
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• 2003

For synchronous direct sequence-code division multiple access (DS-CDMA) systems, the authors propose an adaptive radial basis function (RBF) receiver with suboptimal structure that reduces not only the complexity with regard to the number of centers but also the quantity of instructions required per one bit reception. The proposed receiver is constructed with parallel RBF networks. Each RBF network has the same procedure as the conventional RBF receiver. The performance of each RBF network is affected by interferences which are assigned to the other RBF networks because neither RBF network uses the full user set. To combat these interferences, the partial IC technique is employed. Monte Carlo simulations over additive white Gaussian noise (AWGN) channels confirm that the proposed receiver with its reduced complexity is able to obtain near-optimum performance. Moreover, the proposed receiver is able to properly cope with a various environment.

• The Journal of Industrial Distribution & Business
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• v.10 no.10
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• pp.45-51
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• 2019

Purpose - The purpose of this study was to propose a win-win development plan for not only suppliers of delivery applications but also traditional market vendor companies and delivery riders by analyzing existing delivery models and presenting a new delivery model to enhance competitiveness of the traditional market using delivery apps. Research desgin, data, and methodology - Specifically, small retailers, such as traditional markets and supermarkets, presented a compromised delivery model that utilizes the platform of specialized delivery app service providers for order reception, and that the delivery is delivered by delivery systems jointly hired by Vendor companies, such as franchising companies. To validate the significance of the trade-off delivery model, a cost-benefit analysis was conducted by those involved in the delivery application. Results - From the perspective of suppliers of specialized delivery applications, it is analyzed that the use of specialized delivery applications in traditional markets will be a new market opportunity for service providers to achieve increased sales. It is expected that consumer choice and satisfaction will be increased as convenience and accessibility of traditional market businesses that were available only through direct visit from the user side of the delivery application will be expanded. From the standpoint of delivery application franchises, it is analyzed that they can seek to increase sales and increase customer service as well as ease labor cost burden due to joint employment of delivery riders. The delivery rider will be able to seek to improve customer service due to job security, wage stability, risk reduction and overheated competition due to direct employment. Conclusion - In conclusion, the compromised delivery model solved the problems raised in the preceding study conducted on delivery application suppliers, users, franchises, and riders to establish that it could be a strategic alternative to increasing sales and expanding detailed rights for the self-employed in the traditional market, which are experiencing difficulties in management. However, the adoption of a compromise delivery model requires social consensus from those involved in the delivery application and requires legal, institutional and policy support, which will require continued follow-up research on the delivery model in the future.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.5
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• pp.1-14
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• 1997

We consider transmission beamforming techniques for frequency-division-duplex (FDD) wireless communication systems using adaptive arrays to improve the signal quality of the array transmission link. We develop a simple effective transmission beamforming technique based on an approximated frequency tranlsation (AFT) to derive the tranmsiion beamforming weights from the uplink channel vector. This technique exploits the invariance of the short-time averaged fast fading statistics to small frequency translations. A simple approximate relationship that relates the transmission channel vector to the reception channel vector is derived. We have developed its practical alternative in which the frequency translation of the channel vector is performed at the principal angle of arrival (AOA) of the u;link synthestic angular spectrum instead of the mean AOA. To analyze the performance of the proposed methods, we consider the power loss incurred by applying the estimated channel vector instead of the true downlink channel vector. The performance is analyzed as a function of the mean AOA, the angular spread, the number of elements, frequncy difference between the uplink and the downlink, and the angle distribution. Their performance is also compared with that of the direct weight reuse method and the AOA based methods.

• Korean Institute of Interior Design Journal
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• v.13 no.6
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• pp.167-174
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• 2004

The purpose of this study is to examinethe present illumination conditions in office environment and to suggest an efficient illumination plan in office planning process. Illumination conditions in work environment were surveyed in 6 offices to investigate whether the present illumination conditions were appropriate to the work type. The results of this study are as follows: Most of the general Illuminance level in the area of work were all at an adequate level, except one. The average Illuminance level in the all meeting rooms were met for the standard. Illuminance in the all reception area were extremely over the standard, The illuminations of this area were rather designed according to the image of the company than the standard. As for the illumination method in the area of general work, four offices used a general lighting by a direct lighting type, while two offices used a general lighting and a task lighting at the same time. This survey suggested that first, each company should consider illumination plan in the building planning process, second, illumination plan considering the type of places is needed, and third, illumination environment may be differentiated according to the work type. In conclusion, efficient illumination environment should be considered in office building planning process, especially In terms of illumination materials and methods.

• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.188-196
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• 2003

In this paper, a demultiplexer for MPEG-2 Transport Stream which can be applied to terrestrial digital broadcast is developed. The demultiplexer separates video, audio, and data from MPEG-2 multimedia stream and transports them to each decoders respectively. While most existing demultiplexers of MPEG-2 transport stream have been developed as hardware systems, but the fast increment of computer's performance enables a software demultiplexer to be worked in realtime. The developed demultiplexer is implemented as a software module called a filter using DirectShow of Microsoft which is based on COM(Component Object Model)and works on the Windows system. The operation of the demultiplexer is verified by using the GraphEdit tool and rendering a test file formatted as MPEG-2 transport stream.