• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2023.11a
• /
• pp.21-22
• /
• 2023

충방전조절기 PCB(PRINTED CIRCUIT BOARD) 내 션트저항단 저항을 개선하여 표준 S/W 데이터 오류 수정

• Journal of Energy Engineering
• /
• v.29 no.3
• /
• pp.64-73
• /
• 2020

This paper presented a methodology for calculating daily load curves per city by taking into account the charging/discharging location of electric vehicle. In other words, this is the daily load curve calculation algorithm by city, which takes into account the charging/discharging location of electric vehicles, so that the impact of loads generated by charging/discharging of electric vehicles on the power grid can be easily understood in certain cities. Specifically, in accordance with the PEVs share scenario, the PEVs discharge power was calculated to reflect both the characteristics of the arriving vehicle in the morning and the SMP plan after establishing a assumption that the electric vehicle arrived at work in the morning and the electric vehicle arrived at home in the afternoon for each of the charging/discharging locations, that is, work and home, of electric vehicles in the city. After calculating the daily load curve for each charging/discharging power type for the PEVs charging strategy, which takes into account both the characteristics of the vehicle arriving at home in the afternoon and the TOU fare system, it was analyzed by comparing the impact assessment on the grid by adding the existing load.

• Journal of fish pathology
• /
• v.10 no.1
• /
• pp.21-29
• /
• 1997

We investigated on the prevalence and extermination of scuticociliatids parasitic on cultured japanese flounder, Paralichthys olivaceus in land-marine tank system of southern Korea from January to February in 1997. The gills and the skin showed the highest infection rate(60%), and the brain showed the lowest(22%). Also, fish secreted large quantity of mucus with a bleeding and ulcerated lesions on the infected sites. The number of the parasites in inflowing sea water, surface water and bottom water of farming tank ranged 0~1 individuals/$100m\ell$, 0~413 individuals/$100m\ell$ and $7\sim7.3{\times}10^4$ individuals/$100m\ell$, respectively. This parasite was died within 2 hours in 50~500 ppm, 48 hours of 10 ppm formalin or hydrogen peroxide, 1 hour in 50~500 ppm, 80 minutes of 10 ppm oligo chitosan and 10 minute in 100% but did not died until 48 hours in 10~70% fresh water.

• Research in Plant Disease
• /
• v.21 no.4
• /
• pp.273-279
• /
• 2015

Major diseases and insect pests in nursery season of strawberry were anthracnose, powdery mildew, Fusarium wilt, two-spotted spider mite, and aphids. Environmental-friendly and chemical application schedules can improve diseases and insect pests control with relatively fewer organic and chemical materials inputs compared with spray programs when it's occurred. Field experiments were performed in 2012 to 2013 according to calendar-based spray programs with environmental-friendly spray calendar (EFSC) and conventional chemical spray calendar (CSC) for controlling diseases and insect pests of strawberry plants cv, Seolhyang during the two nursery seasons. EFSC did reduce the incidence of diseases and insect pests as compared to the non-treated control. Incidence of anthracnose and powdery mildew by EFSC and CSC was similar in 2012 and 2013 seasons. In addition, occurrence of two-spotted spider mite in EFSC in 2013 was similar to those of CSC and was shown highly in early and mid-June both 2012 and 2013 seasons. Occurrence of aphid in EFSC was shown highly in early and mid-June both 2012 and 2013 seasons. These results suggest that EFSC program may be effective for controlling strawberry diseases and insect pests by using environmental-friendly organic materials.

• Journal of the Korean Electrochemical Society
• /
• v.19 no.3
• /
• pp.114-121
• /
• 2016

This study investigates a CFD modeling of the charge-discharge behavior due to heat generation during charge-discharge cycles of a Li-ion secondary battery(LIB). Present LIB system adopted a current-density equation, heat and mass transfer governing equations upon the 1-dimensional system to the thickness direction for the rectangular pouch configuration. According to the 3-kinds of the charge-discharge current densities of 1C($17.5A/m^2$), 3C($52.5A/m^2$) and 5C($87.5A/m^2$) subject to a 3 V of cut-off voltage, a constant-temperature system at 298 K and three different heat generating systems were analyzed with comparison. Battery capacity decreases with increment of charge-discharge densities not only at the constant-temperature system but also at the heat-generating system. The time for charge-discharge cycles increases at the heat-generating system compare to the constant-temperature system. These trends are considered that the increase of temperature due to heat generation causes the decrement of equilibrium potential of electrodes and the increment of diffusivity of Li ions. Furthermore, cooling effects were discussed in order to control the influence of heat generation due to charge-discharge behavior of a Li-ion secondary battery.

• Korean Journal of Environmental Biology
• /
• v.29 no.2
• /
• pp.81-91
• /
• 2011

To understand the spatio-temporal fluctuations and ecological characteristics of heterotrophic dinoflagellate $Noctiluca$ $scintillans$, we investigated their population densities and environmental factors during four seasons at 20 stations of Gwangyang Bay and at 23 stations of Jinhae Bay in 2010. $N.$ $scintillans$ was seasonally abundant during spring and summer, with temperature ranging 15 to $27^{\circ}C$ in the both bays, whereas the density reduced in fall and winter. The populations of $N.$ $scintillans$ at each station in both bays showed a significantly positive relationship with water temperature, indicating that relatively high water temperature within its optimum temperature stimulates the growth of $N.$ $scintillans$ population. In particular, low water temperature (<$4^{\circ}C$) and salinity (<12 psu) led to disappear of $N.$ $scintillans$ population, although they were observed at all season in both bays. Spatio-temporal variations of Chl.$a$ concentration was not significantly correlated with $N.$ $scintillans$ population densities. However, the $Noctiluca$ abundances were also high during spring and summer season when relatively high Chl.$a$ concentration was observed in both bays. This result suggests that standing crops of phytoplankton may be one of important contributing factors to enhance the abundance of $N.$ $scintillans$.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.50-50
• /
• 1999

마이크로 공정을 이용한 초소형 정밀 기계는 공정 기술과 재료 기술의 발전에 의하여 더욱 소형화되고 있으며 특히 기능을 갖는 부분과 이 부분을 제어하는 주변회로의 on-chip화의 요구가 증가되기 시작하였다. 이와 같은 추세에 있어서의 문제점은 초소형 정밀기계 부품 소자의 구동을 위한 에너지원의 개발이다. 즉, 소자의 크기가 작아진 것에 부합되는 초소형의 전지가 필요하게 된 것이다. 따라서 보다 완전한 초소형 정밀 기계 및 마이크로 소자의 구현을 위하여 마이크로 소자와 혼성 (Hybrid) 되어 이용될 수 있는 고성능 및 초소형의 전지의 개발이 필수적이다. 초소형 전지의 구현을 위하여 Li계의 2차 전지를 선택하여 이를 박막화하고 반도체 공정을 도입할 수 있다. 이러한 전지를 박막형 2차 전지 또는 박막형 마이크로 전지(thin film Secondary Battery : TFSB or Thin Film Micro-Battery : TFMB)라 하며 이러한 2차 전지는 일반적인 벌크 전지와 동일하게 cathode/Electolyte/Anode의 구조를 갖는다. 박막의 특성상 전해질은 고상의 물질을 사용하는 것이 벌크형 2차 전지와 다른 점이다. TFSB의 성능은 주로 cathode에 의하여 결정되며 지금까지 많은 cathode 물질에 대한 연구 보고가 발표되고 있다. 반도체 공정을 이용한 TFMB의 제작시 무엇보다 중요한 점은 우수한 고상 전해질 및 anode 물질의 선택에 있다. 최근에 2차 전지를 위한 carbon계 anode를 대체할 수 있는 SnO에 대한 보고가 있는데 이는 한 개의 Sn 원자당 2개 이사의 Li가 반응하여 높은 용량을 갖는 전지의 제작이 가능하기 때문이다. Sno2의 anode는 매우 높은 충전용량을 갖는데 첫 번째 방전시에 Li2O를 생성하여 비가역적 반응을 나타내고 계속되는 충방전 동안 Li-Sn 합금이 생성되어 2차전지의 가역적 반응을 가능하게 한다. SnO2 는 대기중에서 Li 금속보다 안정하기 때문에 전지의 제작 공정 및 사용 면에서 매우 우수한 물질이지만 아직까지 SnO2 구조적 특성과 전지의 충, 방전 특성에 대한 관계의 규명을 위한 정확한 정설은 제시되고 있지 못하다. 본 연구에서는 TFSB anode 물질로써 SnOx박막을 상온에서 여러 전도성 콜렉터 위에 증착하여 그 충, 방전 특성을 보고하였다. 증착된 SnOx박막의 표면은 SEM, AFM으로 분석하였으며 구조의 분석은 XR와 Auger electron spectroscope로 하였다. 충, 방전 특성을 분석하기 위하여 리늄 foil을 대극과 참조 전극으로 하여 EC:DMC=1:1, 1M LiPF6 액체 전해질을 사용한 Half-Cell를 구성하여 100회 이상의 정전류 충, 방전 시험을 행하였다. Half-Cell test 결과 박막의 구조, 콜렉터의 종류 및 Sn/O비에 따라 서로 다른 충, 방전 거동을 나타내었다.

• The Korean Journal of Quaternary Research
• /
• v.23 no.2
• /
• pp.48-55
• /
• 2009

To investigate the paleoceanographic environmental changes around the Okinawa Trough, Japan, a piston core (RN88-PC5) was conducted on benthic foraminiferal species composition, assemblage, sedimentological and geochemical analyses. Trubidite sediment intercalated in studied core contains different benthic foraminiferal species, dwelling in shallow coral reef species, from normal hemipelagic sediment. These different benthic foraminiferal species and its assemblage are interpreted as reworked sediment when turbidite current occurred, synchronically. Grain size analysis clearly showed that mean grain size difference occurred between trubidite and hemipelagic sediments. Geochemical analysis also showed the difference of chemical composition between two sedimentary facies. Results of the foraminiferal oxygen isotope analysis showing global surface water warming records since the last 10 ka. The geochemcial analysis and previous works showed that turbidite sediment of studied core indicating sporadic occurrence of regional paleoceanographic events. Assemblage of shallow coral reef benthic foraminifera especially occurred with turbidite layer clearly support the sporadic occurrence of paleoceanographic events such as regional earthquake.

• Parasites, Hosts and Diseases
• /
• v.26 no.4
• /
• pp.275-284
• /
• 1988

This study was performed to observe the present status of intestinal parasitic infections in a remote island, Yondo, located in southern part of Jeonranam-do (Province) , Korea. In February and May, 1988, total 1,011 individual stool samples were collected and examined for intestinal helminths and protozoa using formalin-ether centrifugal sedimentation technique. The results are summarized as follows: 1. Of 1,011 inhabitants examined, 398(39.4%) were positive for intestinal parasites. Helminth positives were 372(36.8%) , and protozoan cyst positives were 56(5.5%) . 2. Ten species of parasites were found. Trichuris trichiura revealed the highest infection rate of 27.5%, Ascaris lumbricoides 17.4%, Taenia sp. 5.8%, Entamoeba coli 3.3%, Ciardia Zamblia 1.5%, Endelimax nasa 0.8%, Hymenolepis nana 0.4%, Hookworm 0.2%, Trichostrongylus orientalis 0,2%, and Entamoeba histolytica 0.2%, respectively. 3. The female group showed higher positive rate(44.0%) than males (34.7%). Also, higher positive rates were observed among adults as compared with the group younger than 10 years old. 4. Average value of E.P.G. was 1,876(range 200∼17,800) in A. lumbricoides positives, and 327 (range 200∼1,600) in T. trichiura positive cases. 5. In helminth egg Positive cases, single in(traction was 63.4%, double infection 34.7%, and triple infection 1.9%, respectively. Among protozoan cyst positives, single infection was 94.6%, and double infection was 5.4%. The present study revealed that the prevalence of intestinal parasites among inhabitants in Yondo island is still so high that special control measures should be performed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.4 no.2
• /
• pp.144-154
• /
• 1999

Masan Bay is highly polluted by the discharge of large quantities of effluents from the industrial complex and domestic sewage of Masan City, Southeast Korea. Surface sediments from 9 stations were used for geochemical and foraminiferal analyses in order to investigate foraminiferal response to sedimentary pollution in the Bay. The heavy metal concentrations in sediments are relatively higher than those in Kyeonggi Bay and Daesan area, west coastal region of Korea. Zn, Cd, Pb, and As are more concentrated than in world average shale, indicating that the municipal and industrial effluents cause sediment contamination. Responses of benthic foraminifera to the sedimentary pollution effect document a degree of pollution in Masan Bay. The species number and diversity in Masan Bay had lower values than those in Gadeog Channel. In Masan Bay, agglutinated foraminifera are abundant and calcareous foraminiferal tests were frequently pyritized. Eggerella advena and Trochammina pacifica dominated at levels of pollution and could be opportunistic species. These data will provide a baseline for future assessments of environmental quality in Masan Bay.