• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.53-60
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• 1987

This experiment was performed on mice to investigate the effects of an immunopotentiator, picibanil(PC), on the immune responses such as phagocytic activity of reticuloen-dothelial(RE) system, E rosette formation rate of splenic lmphocytes and morphological changes of lymph node tissue. Groups of mice were treated with a single(1KE/kg BW) or sequential(0.1, 0.25 and 0.5KE/kg BW for successive 3 days) intravenous injections of PC. PC treated and untreated control mice were sensitized with 50% sheep erythrocyte suspension(0.2ml/mouse) at 1, 3, 5, 7 and 10 days after PC treatment. Functional and morphological examinations were carried out 5 days after sensitization. The following results were obtained: The phagocytic activity of RE system and the weight of liver and spleen were increased significantly at 3rd, 5th and 7th day. The peripheral polymorphonuclear leukocyte and percent of lymphocyte and monocyte were slightly increased. The rates of E rosette formation of splenic lymphotytes, sequential PC treated groups were more increased at 3rd and 5th day in sequential PC treated groups than in single treated groups. Thereafter it returned gradually to the control level by the time of 10th day. Microscopically primary lymph follicles with indistinct germinal center (GC) were partially disrupted and the parafollicular areas were consisted of the pyroninophilic cells in control group. In PC treated group, the parafollicular areas were markedly proliferated and developments of secondary lymph follicles with enlarged and prominent GC were more pronounced in the sequential injected groups compared to single injected groups. These results indicate that PC affected not only parafollicular area of the T-cell area, but also GC of the B-cell area. It suggests that PC may potentiate both cell mediated immunity and humoral immunity.

• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.327-338
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• 2022

This study determined the recent status and trend of Pneumocystis jirovecii pneumonia (PcP) in the non-human immunodeficiency virus (HIV) (non-HIV-PcP) and HIV (HIV-PcP) infected populations using data from the Health Insurance Review & Assessment Service (HIRA) and the Korea Disease Control and Prevention Agency (KDCA). SaTScan and Join-point were used for statistical analyses. Non-HIV-PcP cases showed an upward trend during the study period from 2010 to 2021, with the largest number in 2021 (551 cases). The upward trend was similar until 2020 after adjusting for the population. Seoul had the highest number of cases (1,597) in the non-HIV-PcP group, which was the same after adjusting for the population (162 cases/1,000,000). It was followed by Jeju-do (89 cases/1,000,000). The most likely cluster (MLC) for the non-HIV-PCP group was Seoul (Relative Risk (RR)=4.59, Log Likelihood Ratio (LLR)=825.531), followed by Jeju-do (RR=1.59, LLR=5.431). An upward trend was observed among the non-HIV-PcP group in the Jeju-do/Jeollanam-do/Jeollabuk-do/Gyeongsangnam-do/Busan/Daejeon/Daegu/Ulsan joint cluster (29.02%, LLR=11.638, P<0.001) located in the southern part of Korea. Both women and men in the non-HIV groups showed an overall upward trend of PcP during the study period. Men in the 60-69 age group had the highest annual percentage change (APC 41.8) during 2014-2019. In contrast, the HIV groups showed a falling trend of PcP recently. Men in the 60-69 age group had the most decrease (APC -17.6) during 2018-2021. This study provides an analytic basis for health measures and a nationwide epidemiological surveillance system for the management of PcP.

• Journal of Korean Public Health Nursing
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• v.16 no.1
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• pp.190-200
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• 2002

This study was carried out to investigate and analyze TSP of the PC rooms. The concentration of the total suspended particulate and heavy metals contained in the total suspended particulate of the 15 PC rooms located in one local city were measured. The statistical correlation coefficients between the total suspended particulate and factors of the indoor condition (number of fan or size of pc room, illumination), between the heavy metals and factors of the indoor condition were studied. The results are as follows: 1. The factors of the indoor condition of the 15 PC rooms are as follows. Average illumination was 24 luxes. Average number of computers installed were 37. Average number of the fans was 7. and the size of investigated PC rooms was $139.94m^2$. 2. The mean age of the subjects was 21.8 years old. they $(51.5\%)$ used the 15 pc rooms for fewer than 2 hours per one day. 3. The mean concentration of total suspended particulate (TSP) is lower in the evening ${139.085\;(2.462)\;{\mu}g/m^3}$ than the night ${166.216(2.609){\mu}g/m^3}$. 4. The mean concentration of total suspended particulate was industrial work area) residential area) commercial area. 5. The distribution of heavy metals were indicated as Zn>Cr>Pb>Cd in the indoor air at PC rooms. and the concentration rate of Zn was the highest among heavy metals. but this increase didn't show any relationship with many factors of indoor condition (number of fan or size of pc room, lighting) 6. The concentration of TSP & heavy metals didn't have any relationship between the factors of indoor environment (number of fans, size of pc room, lighting).

• Polymer(Korea)
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• v.35 no.6
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• pp.537-542
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• 2011

Fracture behaviors of polycarbonate (PC)/polyestrercarbonate (PEC) blends and their miscibility have been examined to find out the mechanism of ductilie-brittle transition of fracture behavior which would be a main governing factor on the thickness sensitivity of impact strength of PC. $T_g$ measurement showed that PEC with a carbonate content higher than 30 mol% was miscible with PC. In the notched Izod impact test of PC, ductile-brittle transition occurred in the range of 4 to 5 mm thickness. The impact strength of miscible PC/PEC5 blends ductile-fractured in the thin specimens decreased with increasing PEC5 content, which was in accordance with the decrease of elongation at break in tensile test. In the brittle fracture of the thick specimens, the impact strength was well correlated with the plastic zone size in the vicinity of the notch tip.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.798-803
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• 2018

In order to use Si as an anode material for lithium-ion battery, the particle size was controlled to less than $0.5{\mu}m$ and carbon was coated on the surface with the thickness less than 10 nm. The carbon fiber was grown on the Si surface with 50~150 wt%, and the carbon coating was carried out once again. The Si composite material was mixed with dissimilar metals to increase the conductivity, and graphite was mixed to improve cyclic life characteristics. The physical and electrochemical characteristics of composite materials were measured with XRD, SEM, TEM and coin cell. The discharge capacity of Si/PC/CNF/PC was lower than that of Si/PC (Pyrolytic Carbon)/CNF (Carbon Nano Fiber). However, the cyclic life of Si/PC/CNF/PC was higher. Initial discharge capacity of 1512 mA h g-1 at 0.2 C rate and initial efficiency of 78% were shown. It also showed a capacity retention of 94% in 10 cycles.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.211-224
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• 2015

Financial companies have invested a lot in their disaster recovery system and exercised training more than once a year to comply related laws and regulations. But massive PCs(Personal Computers) became disrupted simultaneously and it took a lot of time to recover massive PCs concurrently when March 20 cyber attack occurred. So, it was impossible to meet the tartgeted business continuity level. It was because the importance of PC recovery was neglected compared to other disaster recovery areas. This study suggests the measure to recover massive branch terminal PCs of financial companies simultaneously in cost-effective way utilizing the existing technology and tests recovery time. It means that in the event of disaster financial companies could recover branch terminal PCs in 3 hours which is recommended recovery time by regulatory body. Other financial companies operating similar type and volume of branches would refer to the recovery structure and method proposed by this study.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.11-15
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• 2004

This paper deals with EMC filter for a personal computer( PC). A PC contains many sources of noise inside and out, with many connected cables. High noise levels are also emitted from the PC became of high-speed signals. So radiated noise from the computer body may sometimes cause problems. Therefore, we design and fabricate an electromagnetic compatibility (EMC) filter for PC, which is composed of feed-through capacitors and ferrite beads with high permeability. Through extensive test, the proposed EMC filter is shown to have excellent differential-mode and common-mode noises filtering characteristics above 30 dB in the frequency band from 10 MHz to 1.5 GHz. The immunity characteristics are improved more than 10 to 30 dB over the frequency band from DC to 1.8 GHz

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.715-719
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• 2004

This paper deals with EMC filter for a personal computer(PC). A PC contains many sources of noise inside and out, with many connected cables. High noise levels are also emitted from the PC because of high-speed signals. So radiated noise from the computer body may sometimes cause problems. Therefore, we design and fabricate an electromagnetic compatibility (EMC) filter for PC, which is composed of feed-through capacitors and ferrite beads with high permeability. Through extensive test, the proposed EMC filter is shown to have excellent differential-mode and common-mode noises filtering characteristics above 30 dB in the frequency band from 10 MHz to 1.5 GHz. The immunity characteristics are improved more than 10 to 30 dB over the frequency band from DC to 1.8 GHz.

• 정보화사회
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• s.124
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• pp.78-86
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• 1998

한국정보통신진흥협회에서는 지난 4월부터 고객에게 일방적으로 불리하게 적용된 PC통신.인터넷서비스의 이용약관을 개선, 이용자 보호규정 등이 강화되도록 정부 및 PC통신.인터넷서비스와의 협의를 거쳐 최근, “PC통신.인터넷서비스 기본약관” 제정작업을 완료하고 각 사업자의 여건에 따라 7월1일까지 시행하기로 하였다.

• Journal of the KSME
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• v.30 no.S1
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• pp.38-44
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• 1990

본 글에서는 PC가 정밀계측 및 측정분야에 있어서 어떻게 응용될 수 있는가를 몇 가지 실예를 들어 기술하였다. 결론적으로 현재의 PC에 관한 기술과 앞으로의 발전 가능성을 고려할 때 동 분야에서의 PC의 응용은 기술적 및 경제성의 어려움은 극히 미약하다고 할 수 있는 반면 응용 효과는 대단하다고 할 수 있다. 그러므로 본 분야에 종사하고 있는 연구진과 기업들은 국내의 측정기술의 도약을 실현하기 위해 이러한 응용연구에 주력하여야 한다고 믿는다.