• Genomics & Informatics
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• v.6 no.1
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• pp.44-49
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• 2008

Protein kinase C (PKC) is a family of kinases involved in the transduction of cellular signals that promote lipid hydrolysis. PKC plays a pivotal role in mediating cellular responses to extracellular stimuli involved in proliferation, differentiation and apoptosis. Comparative analysis of the PKC-${\alpha},{\beta},{\varepsilon}$ isozymes of 200 recently sequenced microbial genomes was carried out using variety of bioinformatics tools. Diversity and evolution of PKC was determined by sequence alignment. The ser/thr protein kinases of Streptomyces coelicolor A3 (2), is the only bacteria to show sequence alignment score greater than 30% with all the three PKC isotypes in the sequence alignment. S.coelicolor is the subject of our interest because it is notable for the production of pharmaceutically useful compounds including anti-tumor agents, immunosupressants and over two-thirds of all natural antibiotics currently available. The comparative analysis of three human isotypes of PKC and Serine/threonine protein kinase of S.coelicolor was carried out and possible mechanism of action of PKC was derived. Our analysis indicates that Serine/ threonine protein kinase from S. coelicolor can be a good candidate for potent anti-tumor agent. The presence of three representative isotypes of the PKC super family in this organism helps us to understand the mechanism of PKC from evolutionary perspective.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.3
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• pp.59-62
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• 2013

Experimental analyses on the solder joint reliability of plastic ball grid array under harsh random vibration were presented. The chips were assembled on the daisy chained circuit boards for the test samples preparation, half of which were processed for underfill to investigate the underfill effects on the solder failures. Acceptance and qualification levels were applied for the solder failure tests, and the overall controlled RMS of the power spectrum densities of the steps were 22.7 Grms and 32.1 Grms, respectively. It was found that the samples survived without any solder failure during the tests, demonstrating the robustness of the packaging structure for potential avionics and space applications.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.456-460
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• 2012

This study was carried out as a survey on the level of lead (Pb), cadmium (Cd), arsenic (As) and mercury (Hg) in 5 items of agricultural products (lettuce, pumpkin, head lettuce, cabbage and crown daisy) for which safety guidelines are not yet established in Korea. The 407 samples were collected from local markets in 9 regional places and the levels of metals were measured by ICP-MS and mercury analyzer. The average levels of Pb, Cd, As and Hg were 0.026, 0.018, 0.008 and 0.003 mg/kg for lettuce, 0.002, 0.001, 0.001 and 0.0006 mg/kg for pumpkin, 0.002, 0.005, 0.001 and 0.0005 mg/kg for head lettuce, 0.001, 0.002, 0.0002 and 0.0006 mg/kg for cabbage and 0.022, 0.014, 0.006 and 0.004 mg/kg for crown daisy. For risk assessment, the daily dietary exposures of Pb, Cd and Hg by intake of these agricultural products were calculated and compared with PTWI (provisional tolerable weekly intake) established by JECFA. The daily dietary exposure of heavy metals by intake of these agricultural products were 0.13, 0.56 and 0.09% of PTWI, respectively. These monitoring results will be utilized as fundamental data for the establishment of Korean standards of Pb, Cd, As and Hg in 5 items of agricultural products and valuable source for DB construction for science-based safety control of heavy metals in foods including agricultural products.

• Journal of the Korean Dietetic Association
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• v.3 no.1
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• pp.55-62
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• 1997

The waste rates of 98 food items after pre-preparation were surveyed to provide database for good menu planning. The waste rates turned out 0-64.27% in vegetables, 6.38-7.03% in potatoes, 6.25-68.75% in fishes and shellfishes, 16.61% in eggs, and 16.00-56.84% in fruits. Foods with high waste rates were vegetables, fishes and shellfishes. Survey results were compared with other food composition tables. Foods with 30% higher waste rate than other food composition tables were squash leaf, pacific ocean perch, sweet potato stalk, water cress, green peas, alaska pollack, bluefin tuna, beka squid, crown daisy, dodok, amaranth, beef ribs. Food which waste rates turned out to be decreased by about 30% in this study were corb shell, pomfret, sea mussel, warty sea squirt. For the menu planning, reasonaly exact waste rates for each food items are essential. Since survey results show significant deviations, there should be more studies for exact waste rates for each food.

• Journal of the Korean Society of Food Culture
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• v.11 no.1
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• pp.23-35
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• 1996

The main purpose of this study was to observe the effect of school lunch program on dietary habits of elementary school children and their food preferences. A questionnaire survey was conducted on 785 children and their mother in ele-mentary school with and without school lunch program. The results of this study can be summarized as follows: 1. 91.1% of subjects were eating rice for breakfast menu and 12.2% of subjects were skipping breakfast every morning. 2. Most of the children preferred fruits, ddugboggi, ice cream, fritter, cookie, bread, beverage and hot dog for snacks. 3. Despite of its restrictive practice, the school lunch program proved to be contributory to the improvement of children's food intake habits, table manners, keeping social order, sanitary consiousness, gratitude for their parents. 4. Children preferred kimbap, bokumbap and hamburger for main dish, fish jelly soup, brown seaweed soup and bean-sprout soup for soup, animal food for side dish and frying saute for cooking methods. 5. Most of the children disliked crown daisy, green pepper, mushroom, green onion, onion, dropwort, soybean and carrot for their food materials.

• Korean Journal of Metals and Materials
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• v.46 no.2
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• pp.80-87
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• 2008

Many researches related to the reliability of Pb-free solder joints with PCB (printed circuit board) surface finish under thermal or vibration stresses are in progress, because the electronics is operating in hash environment. Therefore, it is necessary to assess Pb-free solder joints life with PCB surface finish under thermal and mechanical stresses. We have investigated 4-points bending fatigue lifetime of Pb-free solder joints with OSP (organic solderability preservative) and ENIG (electroless nickel and immersion gold) surface finish. To predict the bending fatigue life of Sn-3.0Ag-0.5Cu solder joints, we use the test coupons mounted 192 BGA (ball grid array) package to be added the thermal stress by conducting thermal shock test, 500, 1,000, 1,500 and 2,000 cycles, respectively. An 4-point bending test is performed in force controlling mode. It is considered that as a failure when the resistance of daisy-chain circuit of test coupons reaches more than $1,000{\Omega}$. Finally, we obtained the solder joints fatigue life with OSP and ENIG surface finish using by Weibull probability distribution.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.09a
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• pp.261-278
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• 2003

Concepts.Wafer-Level Chip-Scale Concept with Handling Substrate.Low Accuracy Placement Layout with Isolation Trench.Possible Pitch of Interconnections down to $10{\mu}{\textrm}{m}$ (Sn-Grains).Wafer-to-Wafer Equipment Adjustment Accuracy meets this Request of Alignment Accuracy (+/-1.5 ${\mu}{\textrm}{m}$).Adjustment Accuracy of High-Speed Chip-to-Wafer Placement Equipment starts to meet this request.Face-to-Face Modular / SLID with Flipped Device Orientation.interchip Via / SLID with Non-Flipped Orientation SLID Technology Features.Demonstration with Copper / Tin-Alloy (SLID) and W-InterChip Vias (ICV).Combination of reliable processes for advanced concept - Filling of vias with W as standard wafer process sequence.No plug filling on stack level necessary.Simultanious formation of electrical and mechanical connection.No need for underfiller: large area contacts replace underfiller.Cu / Sn SLID layers $\leq$ $10{\mu}{\textrm}{m}$ in total are possible Electrical Results.Measurements of Three Layer Stacks on Daisy Chains with 240 Elements.2.5 Ohms per Chain Element.Contribution of Soldering Metal only in the Range of Milliohms.Soldering Contact Resistance ($0.43\Omega$) dominated by Contact Resistance of Barrier and Seed Layer.Tungsten Pin Contribution in the Range of 1 Ohm

• Journal of the Microelectronics and Packaging Society
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• v.19 no.3
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• pp.31-36
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• 2012

In this study, the complex vibration reliability of Sn-3.5Ag and Sn-0.7Cu having a high melting temperature was investigated. For manufacturing of BGA test samples, Sn-3.5Ag and Sn-0.7Cu balls were joined on BGA chips finished by ENIG and the chips were mounted on PCB finished OSP by using reflow process. For measuring of resistance change during complex vibration test, daisy chain was formed in the test board. From the results of resistance change and shear strength change, the reliability of two solder balls was compared and evaluated. During complex vibration for 120 hours, Sn-0.7Cu solder was more stable than Sn-3.5Ag solder in complex vibration test.

• Journal of the Korean Society for information Management
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• v.32 no.2
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• pp.221-236
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• 2015

This paper describes the process and methodology followed in developing the Android-based LG Sangnam Audiobook service and an evaluation of its usefulness to the public. The methods included a survey of user needs, analysis of usage statistics, and user interviews. The study found that visually impaired users: 1) were greatly interested and willing to use smartphones if there were no barrier in cost and access; 2) preferred downloads to streaming services; 3) did not mind performance differences between real and TTS (text-to-speech) voices; 4) showed marked differences in book preferences according to age, 5) made about 14,000 downloads in 2014; and 6) indicated bookmarking and moving between pages and tables of content as the most important functions in using audiobooks.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.1
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• pp.55-63
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• 1999

This research was conducted to estimate waste rates of 69 food items after pre-preparation and amounts of food wastes disposed and it's reduction effect by education in some institutional foodservices for reduction of the food wastes. The result are as follows: 1. The waste rates were 55.40% for sweet corn, 5.73% for potatoes, 19.14% for sweet potatoes, and 33.47% for chestnuts. 2. The waste rates of fruits were 0.21-49.36%. Food items with over 40% waste rate were banana, watermelon, and pineapple. 3. The waste rates of vegetables were 1.14-52.90%. The number of foods with under 10% waste rate were 14 items(red pepper, green pepper, chard, and so on), 10-20% was 9 items(perilla leaf, chinese cabbage, ginger root, and so on), 20-30% was 5 items(root of chinese bellflower, garlic, radish-leaves, burdock, welsh onion-large type), 30-40% was 3 items(shepherd's purse, head lettuce, kale) and over 40% was 3 items(water dropwort, crown daisy, mallow). 4. The waste rates were 24.30% in chicken, 9.53-13.79% in eggs, and 9.30-55.32% in fishes. The waste rates of vegetables and fishes were higher than those of other food groups. 5. There were significantly different in amount of food wastes disposed (g/person/day) to institutional foodservices (hospital＞industrial institution＞ Korean restaurant＞elementary school). The amount of food wastes disposed, especially amount in pre-preparation phase, after education for reduction of food wastes was significantly reduced. Since these study results show significant deviations in food waste rates and education effect, there should be more studies for standard waste rates of each food and systematic education method for reduction of food wastes.