• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.5
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• pp.1291-1298
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• 1998

In this paper, a simple algorithm for detection of timing error of a synchronous, band-limited, multi-level data stream is proposed. The proposed algorithm can be applied to multi-level PAM, M-ary PSK, or M-ary QAM. The proposed algorithm for M-ary PSK requires only two samples per symbol for its operation, and it is based on the concept of transition logic table and transition level table. In orer to prove the steady-state operation of the proposed algorithm, its performance is evaluated and compared to BECM by Monte Carlo simulation method under Gaussian noise and fading noise channel environments. The comparison results confirm that the perforance of proposed algorithm is superior to that of BECM in jitter characteristics.

• Korean Management Science Review
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• v.12 no.2
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• pp.43-62
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• 1995

For a complex scheduling system like time table construction, its optimal solution, if exists, is hard to obtain. In this paper, the scheduling environment is reasonably confined as where objects have their own events competing for better slots on boards, and objects have their own board slot preferences and belong to one or more classes of the society which globally constrains them. Here, two phase method is suggested, where the first phase is human-like preference driven and the second phase is for fine tuning by considering all the factors given. Designed and implemented in our system HI-SCHED are dynamic object switching, temporal-constraint-driven intelligent backtracking, case-based revisions, object-based approach, and so on. Some satisfaction degrees are also defined to measure the usefulness of our method. In addition, look-ahead dynamic object switching is considered, and additional global constraints are introduced and processed. A simple scheme is also used to verify the usefulness of the post processing scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.747-752
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• 1996

In this paper, we propose a new SO-MLSE(soft-output maximum likelihood sequence estimation) equalizer, which can be used in GSM digital cellular system) it uses complex correlation of training sequence to obtain the channel information and the equalization is performed by MLSE using Viterbi algorithm. In order to generate a soft-decision input to channel decoder (Viterbi decoder), the soft-output equalization algorithm is needed. The adopted algorithm doesn't require to modify the structure of HO-MLSE(hard output MLSE) equalizer, that is, SO-MLSE equalizer can be implemented by adding soft-output generation block to HO-MLSE equalizer. This algorithm uses the outputs of matched filter and HO-MLSE equalizer. It turns out that the complexity of proposed SO-MLSE equalizer is simpler than those of other SO-MLSE equalizer and its perforance is almost the same as those of others. Finally, the proposed SO-MLSE equalizer is also implemented s a prototype with ADSP-2101 16-bits fixed point digital signal processing chip.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.2
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• pp.79-93
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• 1997

This paper presents a linear shift-invariant system euqivalent to morphological dilation for a memoryless uniform source in the sense of the power spectral density function, and comares it with dialtion. This equivalent LSI system is found through spectral decomposition and, for dilation and with windwo size L, it is shown to be a finite impulse response filter composed of L-1 delays, L multipliers and three adders. Th ecoefficients of the equivalent systems are tabulated. The comparisons of dilation and its equivalent LSI system show that probability density functions of the output sequences of the two systems are quite different. In particular, the probability density functon from dilation of an independent and identically distributed uniform source over the unit interval (0, 1) shows heavy probability in around 1, while that from the equivalent LSI system shows probability concentration around themean vlaue and symmetricity about it. This difference is due to the fact that dilation is a non-linear process while the equivalent system is linear and shift-ivariant. In the case that dikation is fabored over LSI filters in subjective perforance tests, one of the factors can be traced to this difference in the probability distribution.

• Journal of Korean society of Dental Hygiene
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• v.1 no.1
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• pp.53-62
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• 2001

The purpose of this study was to measure of dental impact on daily lining among workers. The number of subjects were 1.457 workes. To predict the oral health of workers, we used the measurement of dental impact on daily living. Using methodology was self-questionnaire which included the perceived oral health status, and performance, appearance, pain, eating restriction and discomfort. The associations between the performance factors and perceived oral health status, pain, eating restriction and discomfort, the results were as follows: 1. There were consisted of 48.3% of female. 63.1% of smokers. 92.3% of lower than 30years and 99.4% of graduating high school. 2. Measurement of daily impact on daily living were classified into the following 6 categories. Facter analysis for validity was carried out for corroboration. 3. Association between performance factors and other factors(pain, eating restriction and discomfort) were evaluated by multiple regression was significant(44%, p<0.01).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3086-3097
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• 1996

Generally, the performance of the computer network may differ according to various parameters like routing, bandwidth and timers. Since the network system requirements may widely very according to specific application, computer network must be tailored at tailored at the design starge by selection of appropriate protocols and assignment of degfault parameter. However, since the condition under which a network actually operates may change from that considered at the design stage, control and managment action are required to adjust the network parameter so that the perforance of network is satisfied.

• Journal of the Korean Society of Costume
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• v.32
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• pp.243-259
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• 1997

The object of this research is to inform readers of the chronikal change of Military Uniform in wars how the features and colors of uniforms have been changed along with the innovations of firearms. Military uniforms can be put into two differ-ent categories which are 'Battle wear' and 'Rank wear' A battle wear features of protec-tion and user fiendliness, These features of a battle wear can possibly minimize injuries and help increase the level of battling perform-ance. On the other hand a rank wear help dis-tinguish soldiers from their ranks and posi-tions. A rank wear symbolizs the pride that soldiers take n their unit and by wearing a rank wear soldiers feel more attached to their collegues and unit. Concrete process of military uniforms is as follows. 1. As firearms were innovated corres-pondant innovation of military uniforms were also needed this innovation were in the formstructure design color etc. 2. In the beginning features of military uniforms changed toward protection and then after social status of solders rised features changed forward show-off Finally as firearms became more fortal camouflage became the most significant feature of the military uniforms. 3. During war colors of military uniforms tended to be a means of show -off and camou- flage and while not in war they functioned as symbol which represent froops and the unit is tradition. 4. Other accessaries support the perforance and the symbolical function of uniforms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.91-102
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• 1996

The multicast routing algorithm is necessary to transmit multimedia traffic efficiently in ATM (asynchronous transfer mode) networks. In this paper, we propose the multicast routing algorithm which is based on VP/VC characteristic. The proposed algorithm is based on VP tree concept and using cost function which is based on VP/VC switching. The cost funication is composed of link cost, delay and weighting factor on delay and the weighting factor is calculated by delay sensitivity of the traffic. The proposed algorithm can choose delay bounded path which satisfies delay constraint, moreover it can choose optimal path among VPs which has the same link cost and satisfying delay constraint. With controlling weighting factor, proposed algorithm can set-up efficient path. When the weighting factor sets to be between 0.8 and 1, experimental results show that the perforance of proposed scheme is approximated to that of cost optimal algorithm and strongly delay optimized algorithm.

• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.884-892
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• 1997

Currently, there are 100 community emergency centers which expect to provide professional emergency care like Level 1 trauma centers in U.S.A. To evaluate perforance of emergency centers, most studies have been widely adopted death rate based methods such as Trauma and Injury Severity Score(TRISS) and A Severity Characterization of Trauma(ASCOT). However, these methods are only applicable in situation where registration process of trauma patients is well established. Therefore, an alternative method should be applied to evaluate performance of emergency centers in Korea which does not have well-developed registration scheme. This study aims to develop new performance measures which are applicable to Korea and evaluate performance of 35 community emergency centers through new measures. The new measures are included that 'W-statistic' ; death rate calculated on the basis of International Classification based Injury Severity Score(ICISS), and 'the degree of severity' ; rate of severe trauma patients of each emergency medical centers. The study results can be summarized as follows. First, about 34% of sample emergency centers show they provide proper care in terms of their function. Second, tertiary hospitals, university hospitals, and hospitals located in Seoul show higher severity degree of patients and lower severity-adjusted death rate.

• The Transactions of the Korea Information Processing Society
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• v.5 no.8
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• pp.1997-2012
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• 1998

It is necessary to find out the parallelism in tlle sequential Java program to execute it on the parallel machine. The loop is a fundamental source to exploit parallelism as it process a large portion of total execution time in sequential Java program on the parallel machine. However, a complete parallel execution can hardly be achieved due to data dependence. This paper proposes the method of exploiting the implicit parallelism by structuring a dependence graph through the analysis of data dependence in the existing Java programming language having a nested loop structure. The parallel code generation method through the restructuring compiler and also the translation method of Java source program into multithread statement. which is supported by the Java programming language itself, are proposed here. The perforance evaluatlun of the program translaed into the thread statement is conducted using the trip cunt of loop and the trip Count of luop and the thread count as parameters The resttucturing compiler provides efficient way of exploiting parallelism by reducing manual overhead conveliing sequential Java program into parallel code. The execution time for the Java program as a result can be reduced un the parallel machine.