• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.12
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• pp.51-59
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• 1993

A 4${\times}10^{19}cm^{3}$ carbon-doped base AlGaAs/GaAs HBY was grown using carbontetracholoride(CCl$_4$) by atmospheric pressure MOCVD. Abruptness of emitter-base junction was characterized by SIMS(secondary ion mass spectorscopy) and the doping concentration of base layer was confirmed by DXRD(double crystal X-ray diffractometry). Mesa-type HBTs were fabricated using wet etching and lift-off technique. The base sheet resistance of R$_{sheet}$=550${\Omega}$/square was measured using TLM(transmission line model) method. The fabricated transistor achieved a collector-base junction breakdown voltage of BV$_{CBO}$=25V and a critical collector current density of J$_{O}$=40kA/cm$^2$ at V$_{CE}$=2V. The 50$\times$100$\mu$$^2$ emitter transistor showed a common emitter DC current gain of h$_{FE}$=30 at a collector current density of JS1CT=5kA/cm$^2$ and a base current ideality factor of ηS1EBT=1.4. The high frequency characterization of 5$\times$50$\mu$m$^2$ emitter transistor was carried out by on-wafer S-parameter measurement at 0.1~18.1GHz. Current gain cutoff frequency of f$_{T}$=27GHz and maximum oscillation frequency of f$_{max}$=16GHz were obtained from the measured Sparameter and device parameters of small-signal lumped-element equivalent network were extracted using Libra software. The fabricated HBT was proved to be useful to high speed and power spplications.

• Journal of Digital Contents Society
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• v.3 no.2
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• pp.131-142
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• 2002

This paper announces that, with the emergence of the imaginary university for the remote education, which is based on Web due to the education change, the introduction of the Multimedia contents system using computers and the Internet becomes serious. For this reason, this paper suggests search system for managing the imaginary university documents. For the success of the document management of the imaginary university, document search is regarded as an important issue as well as the executive support and search system of the document management. This paper plans and embodies the imaginary university XML document search system to establish the foundation of increasing efficiency o( affairs using XML document, by aiming at the fact that it will be highlighted as a representative application field as well as the efficiency of the executive affairs, by applying of Multimedia documentary creation system, which is about the imaginary university XML documentary that it is seen distinctly an effect of administrative work being a consequence of new technique application of computers.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.257-264
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• 2006

This study investigated the effects of hybrid process(chemical coagulation, Fenton oxidation and ceramic UF(ultrafiltration)) on COD and color removals of commercial reactive dyestuffs. In the case of chemical coagulation, the optimal concentrations of $Fe^{3+}$ coagulant for COD and color removals of RB49(reactive blue 49) and RY84(reactive yellow 84) were determined according to the different coagulant dose at the optimal pH. They were 2.78 mM(pH 7) in RB49 and 1.85 mM(pH 6) in RY84, respectively. In the case of Fenton oxidation, the optimal concentrations of $Fe^{3+}\;and\;H_2O_2$ were obtained. Optimal $[Fe^{2+}]:[H_2O_2]$ molar ratio of COD and color removals of RB49 and RY84 were 4.41:5.73 mM and 1.15:0.81 mM, respectively. In the case of ceramic UF, the flux and rejection of supernatant after Fenton oxidation were investigated. After ceramic UF for 9 hr, the average flux of RB49 and RY84 solutions were $53.4L/m^2hr\;and\;67.4L/m^2hr$ at 1 bar, respectively. In addition, the permeate flux increased and the average flux recovery were 98.5-99.9%(RB49) and 91.0-97.3%(RY84) according to adopting off-line cleaning(5% $H_2SO_4$). Finally, COD and color removals were 91.6-95.7% and 99.8% by hybrid process, respectively.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.139-146
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• 1989

The purpose of this study was to examine the qualitative variation of human fetal-cord sera (HCS) and to accept the sera in human lVF-ET program. One hundred and sixteenth RCS were tested with 1772 2-cell embryos of F1 (C57BL x CBA) virgin mice, Ten to sixteenth embryos were cultured in m-KRB medium with a aliquot of each serum (10%, v/v) or with bovine serum albumin(O.4%, w/v) as a control medium. Embryonic development were recorded at every 24hr for 4 days by such events as cellular compaction, cavitation, and hatching. In the control groups of eight assays, 98.1%(106/ 108) of 2-ce1l embryos developed above expanded blastocyst and the embryonic development was unified through the tests. But the developmental pattern in medium with each serum was various. Namely, the sera that supported development of 100% 2-cell embryos to above morula, early blastocyst, expanded blastocyst and hatching blastocyst was 45,7%(53/116) , 35.3%(41/116), 15.5%08/116.) and 6.9-%(8/116), respectively. And the sera that supported development of above 80% 2-cell embryos to the each embryonic stage was 92.2% (107/116), 83.6%(97/116), 63.8%(74/116) and 36.2%(42/116), respectively. Meanwhile two kinds of toxic pattern to the embryonic development were observed in some sera. The first pattern is that some sera arrested development of most embryos in pre- or post-stage of morula or blastocyst. The second pattern is that some sera promoted or arrested a part of embryos in the same dish. The ability of serum was depended on the batch of serum. Finally we could accept 69%(80/116) of the tested sera for human IVF-ET program. The base line for acceptance was the ability that supported above 80% 2-ce1l embryos to blastocyst. But some deterious sera were contained in this range. We cut off about 10% of the sera (83.6% , 97/116) that passed the baseline. This final percent of sera was similar to that of grade N of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.399-406
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• 2020

The R.O.K Army has developed and operated TM to maintain the operation of weapons systems since its establishment. As more modern weapons systems were developed, the more efficient operation was limited by a large quantity. As a countermeasure, the DAPA has operated the IETM using the KAIS TOOL since 2003. However, 16 years later, they were shunned by operators for software instability and other reasons. Based on the results of an operational test and evaluation team of the Army headquarters, the analysis results of software instability, limited compatibility and integration, limited real-time updates, etc. were analyzed. It was confirmed that KAIS development tools were urgently needed. Therefore, in order to solve this current problem for the Army IETM, the first phase of this paper focused on improving the IETM by maintaining the application present, the second of the Army Electronic Technology manual, phase going to propose improvement plans for operational test and evaluation by lining 11 elements of comprehensive logistics support with an electronic technology code.

• Journal of the Korean Society of Food Culture
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• v.24 no.3
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• pp.331-337
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• 2009

The principal objective of the present study was to survey the demands of an education program for evaluations of the efficacy of health functional foods. A questionnaire was developed and sent to 2,225 members of the Biofood Network Center. A total of 101 (4.6%) individuals responded, 54.5% of the respondents were male and 45.5% were female; the respondents' occupations (in order of prevalence) were as follows: company worker (48.5%)>researcher (27.7%)>student (13.9%)>professor (5.0%)>pharmacist (2%), and dietitian (2%). The businesses in which the respondents worked were (again in order of prevalence) as follows: research & development (64.4%)>marketing (11.9%)>consultation and education (5.9%)>manufacturing and others (17.9%). 41.6% of the respondents reported experience in businesses relevant to KFDA approval for functional ingredients and health functional foods. The results showed that 63.4% of the respondents had previously been educated about functional foods; the types of education program reported were (in order of prevalence): 'overview and acts of health functional food' (n=49)>'standards and specification for health functional food' (n=41)>'efficacy evaluation-human study' (n=24)>'safety evaluation' (n=21)>'efficacy evaluation-in vivo study' (n=13)>and 'others' (n=10). Respondents preferred off-line education programs (62.4%) to on-line programs (22.8%). The preferred duration of an educational program was '$2{\sim}3$ days: total $14{\sim}24$ hours' (30.7%); thus, short-term programs were favored. The primary requirements of a program, from the perspective of the learner, were as follows (scored on a 7-point scale); 'efficacy evaluation and case study-human study' (5.80 points)>'standards and specification for health functional food' (5.72 points)>safety evaluation' (5.7 points)>'overview and acts of health functional food' (5.67 points) and 'efficacy evaluation methods of health functional food by efficacy (intensive)' (5.67 points). Preference for functionality was as follows; 'body weight & body fat' (21.8%), 'immune function' (18.8%) > 'blood glucose' (10.9%). In summary, the educational demand for 'efficacy evaluation and case study' was highest among the curriculum options provided, and with regard to functionality, 'body weight & body fat', 'immune function' and 'skin care' were considered most important by respondents. These results differed among respondents with different jobs and duties, and this suggests that customized education programs for health functional food should be developed.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.10
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• pp.493-501
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• 2007

The imprecise real-time system provides flexibility in scheduling time-critical tasks. Most scheduling problems of satisfying both 0/1 constraint and timing constraints, while the total error is minimized, are NP-complete when the optional tasks have arbitrary processing times. Liu suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on uniprocessors for minimizing the total error. Song et at suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on multiprocessors for minimizing the total error. But, these algorithms are all off-line algorithms. In the online scheduling, the NORA algorithm can find a schedule with the minimum total error for the imprecise online task system. In NORA algorithm, EDF strategy is adopted in the optional scheduling. On the other hand, for the task system with 0/1 constraint, EDF_Scheduling may not be optimal in the sense that the total error is minimized. Furthermore, when the optional tasks are scheduled in the ascending order of their required processing times, NORA algorithm which EDF strategy is adopted may not produce minimum total error. Therefore, in this paper, an online algorithm is proposed to minimize total error for the imprecise task system with 0/1 constraint. Then, to compare the performance between the proposed algorithm and NORA algorithm, a series of experiments are performed. As a conseqence of the performance comparison between two algorithms, it has been concluded that the proposed algorithm can produce similar total error to NORA algorithm when the optional tasks are scheduled in the random order of their required processing times but, the proposed algorithm can produce less total error than NORA algorithm especially when the optional tasks are scheduled in the ascending order of their required processing times.