• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.529-532
• /
• 2001

We synthesized polypyrrole (PPy) by electrolysis of the pyrrole monomer solution containing support electrolyte KCl and/or p-toluene sulfonic acid sodium salt (p-TS). The electrochemical behavior was investigated using cyclic voltammetry and AC impedance. In the case of using electrolyte p-75, the redox potential was about -0.3 V vs. Ag/AgCl reference electrode, while the potential was about 0 V for using electrolyte KCl. It is considered as the backbone forms a queue effectively by doping p-TS Therefore, it is possible to be arranged regularly. That leads to improvement in the electron hopping. The AC impedance plot gave a tent of betterment of mass transport. PPy doped with p-TS has improved in mass transport, or diffusion. That is because the PPy doped with p-TS has a good orientation, and is more porous than PPy with KCl.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.4 no.3
• /
• pp.257-267
• /
• 1999

This paper deals with the water cooling system of HVDC(High Voltage Direct CUlTentJ. It is generally accepted that water is a veη effective medium to remove heat losses from any type of equipment. Because of this benefits the water cooling method is used in HVDC. The water cooling system consists of a heat exchanger, circulation pump and a connecting pipe. According to thYI1stor temperature level. thyristor junction temperature is controlled by controlling the f fan of exchanger. In this paper. the water cooling system of HVDC system is analyzed and estimated.

• Electrical & Electronic Materials
• /
• v.8 no.5
• /
• pp.633-639
• /
• 1995

Dropouts in magnetic media are a primary quality deficiency which is detrimental to magnetic signal quality and thus the major impediment to error-free recording, especially in high density digital recorders. The specific form of defects and causes found to be responsible for signal dropouts occurring in magnetic tape were studied. Dropout occurred when the RF signal falls to low level due to the various types of surface defects. However, the fall in the level of the RF signal in gravure roll coated tapes was most often caused by foreign particles adhering to the magnetic tape. It was also shown from the present study that scattered particles trapped under the tape surface or put on the top can lift it as it crosses the head, creating a spherical tent shaped defect and causing a temporary signal drop. Dropout producing substances were identified through optical and microchemical analyses. The results were correlated with measured electrical signal losses combined with analytical microscopy to clarify source identification of defects.

• Korean Journal of Organic Agriculture
• /
• v.3 no.1
• /
• pp.79-85
• /
• 1994

Worm cast is one of the effective and the least harmful organic fertilizer. The purpost of this work is to elucidate the physiological role of worm cast in the plant growth. Worm cast extract contains 17.83ppm of zinc, but either cadmium or lead were not detected in it. Cucumber (Cucumis sativus L. cv. H. N. Semiwhite) was germinated and incubated with percentage-varied extract. While 10% extract stimulated sprouting of seeds, 100% extract had no effct on it. 50% extract and 100% extract enhanced hypercotyl elongation and fresh weight most effectively. Dry matter and zinc concentration in hypercotyl were increased as percentage of extract increased. Protein con-tent was not affected by extract, 100% extract inhibits water uptake of seedling. Considering these, enhancement of seedling growth was mainly based on increment of water uptake.

• Journal of Advanced Navigation Technology
• /
• v.17 no.3
• /
• pp.292-297
• /
• 2013

In this paper, The design of digital circuits for chaotic composition function which is used for the key-stream generator is studied in this work. The overall design concept and procedure due to the mathematical model of chaotic key-stream generator is to be the explained in detail, and also the discretized truth table of chaotic composition function is presented in this paper. consequently, a composition state machine based on the compositive map with connecting two types of one dimensional and two dimensional chaotic maps together is designed and presented.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.2
• /
• pp.167-174
• /
• 1995

This experiment was carried out to investigate the major characters affecting the popping volume of popcorn. Tuygimok 1 (Kp1 ${\times}$ Kp2) and 8 popcorn hybrids' agronomic characters were tested to evaluate a certain extent how much they affect on the popping volume. Moisture con-tent was considered as the most important factor, but failed to evaluate the optimum moisture con-tent level in this experiment moisture range (12.2-14.4%) because popping volume increased as moisture content of kernels increased. The maximum popping volume was obtained at 55-60kg of kernel hardness, 80-90,um of pericarp thickness and 45-50% of S/H (Soft/Hard starch). But the Em/En(Embryo/Endosperm) ratio was negatively associated with the popping volume. Therefore the minimum popping volume was observed at the 10-11 % of Em/En ratio. Moisture content, hardness, pericarp thickness, Em/En and S/H ratio were selected as the appropriate variables for the maxi-mum popping volume using the stepwise forward regression method and the expecting popping volume was estimated by the multiple linear regression formular. The mean popping volume of ninepopcorn hybrids was about 29.2cm3/g.

• Microbiology and Biotechnology Letters
• /
• v.29 no.4
• /
• pp.234-239
• /
• 2001

In order to maximize the RNA accumulation and biomass production is Saccharomyces cerevisiae MTY62, a high-content RNA yeast strain, batch and fed-batch cultures were performed. Among the feeding modes of fed-batch cultures examined, the intermittent feeding mode R\`(IFB-lV), in which 50 ml of 40% molasses and 20% com steep liquor (CSL) solution was intermittently fed for 5 times, resulted in the cell concentration of 33.8 g- dry cell weight/1 and the RNA concentration of 5221 mg-/l, and RNA content of 153 mg-RNA/g-dry cell weight. The constant fed-batch with feeding mode III (CFB-III), in which the feeding rate of 40% molasses and 20% CSL solution was stepwisely decreased from 48 mph (9-13 h), to 24 mph (13-21 h), and to 18 ml/h (21∼ 48 h), gave the highest cell concentration of 42.7 g-dry ceil weigh71 and R7IA concentration of 5536 mg-RNA/1, which were about 2.4-fold and 1.9-fold increased levels, respectively, compared to the results of batch culture. However, the RNA con- tent of 130 mg-RNA/g-dry cell weight of the fed-batch was lower than that of the batch culture (171 mg-RNA/g-dry cell weight) and other fed-batch cultures. When the specific growth rates in the fed-batch cultures were increased, the RNA contents increased. This result indicates that the RNA content is adversely proportional to the cell concen- tration. However, at the same specific growth rate, the RNA content was maintained at higher level in the intermit- tent fed-batch than in the constant fed-batch culture.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.49 no.1
• /
• pp.29-38
• /
• 2012

Due to the rapid development of network environment and wireless communication technology, the distribution of digital video has made easily and the importance of the protection for digital video has been increased. This paper proposes the digital video encryption system based on multiple chaos maps for MPEG-2 video encoding process. The proposed method generates secret hash key of having 128-bit characteristics from hash chain using Tent map as a basic block and generates $8{\times}8$ lattice cipher by applying this hash key to Logistic map and Henon map. The method can reduce the encryption overhead by doing selective XOR operations between $8{\times}8$ lattice cipher and some coefficient of low frequency in DCT block and it provides simple and randomness characteristic because it uses the architecture of combining chaos maps. Experimental results show that PSNR of the proposed method is less than or equal to 12 dB with respect to encrypted video, the time change ratio, compression ratio of the proposed method are 2%, 0.4%, respectively so that it provides good performance in visual security and can be applied in real time.

• Journal of Wetlands Research
• /
• v.14 no.4
• /
• pp.687-698
• /
• 2012

This study was conducted to monitor and prevent outbreak of insect pestsin dredged soil dumping area after completion of dredging construction in Masan City. Monitoring was carried out using tent trap, colored sticky trap, and CDC light trap. A total of 217,073 individuals belonging to 23 species from 10 families in 3 orders were collected. In overwintering survey using tent trap, 3 species were collected. 2 species (Leptocera fuscipennis (Haliday) and Ephydra japonica Miyagi) of them were outbreak species. In color sticky trap, more than 96% of total individuals were comprised of five species: Urolepis maritima Walker (43%), E. japonica (19%), Fucellia sp. 1 (13%), Philotelma sp. 1 (10%), and Homalometopus sp. 1 (9%). In CDC light trap, three dominant species were Homalometopus sp. 1 (91%), Glyptotendipes tokunagai Sasa (6%), and L. fuscipennis (1%), representing about 98% of the total. To prevent damage caused by outbreak of insect pests, we carried out ecological control methods such as covering the fresh soil in outbreak area, using light trap, pumping up water and so on, minimizing use of thermal fogging and insect growth regulatorwhen the insect pest population was rapidly increasing.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.3
• /
• pp.46-53
• /
• 2019

Recently, the need for emergency medical facilities is increasing due to a large-scale disaster. The Ministry of the Interior and Safety has completed the development of Disaster Resource Sharing System (DRSS). In this system, only air tent and negative pressure tent, which are classified and managed as equipment are resources related to emergency medical facility at disaster site. However, the characteristics of resources for the facility such as the time of input, a period of stay, transportation, and installation methods were not reflected. So, The purpose of this study is to propose improvements of management of resources for emergency medical facility at disaster site, that classified to materials and equipment in DRSS. This study analyzed the state of resources for facilities and the attributes of resources based on literature and disaster medical consultation of mobile hospitals. The resources for emergency medical facility are required to be linked to medical support resources and reflected in the DRSS, since emergency medical facility resources at the disaster site should be managed through a combination of medical resources classified as equipment. And future research on installation of emergency medical facilities plan considering the cost of the disaster management resources should be carried out.