• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.654-660
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• 1998

In preparing PSZT powder by hydrothermal synthesis, effects of reaction temperature, concentration of raw materials and mineralizer on crystallinity, particle size distribution, and dielectric constant were investigated. By varying the concentration of mineralizer and the ratio of Pb to Sr or Zr to Ti, crystalline PSZT powder, having the mean particle size of $0.3{\sim}15{\mu}m$, was prepared by hydrothermal synthesis in the temperature range of $120{\sim}200^{\circ}C$ for a 2h reaction. PSZT ceramics, having dielectric constant of 1000~3000, were prepared at $1150^{\circ}C$ for a 2h sintering reaction of the PSZT powders. Experimental results showed that the weight mean particle size of $0.5{\mu}m$ was obtained when the concentration of KOH in the solution was 10 wt % and the ratio of Pb to Sr was 0.95/0.05, that of Zr to Ti was 0.52/0.48. It also showed that the ceramics of dielectric constant of 2900 were prepared through sintering of this PSZT powder. Size of PSZT particles became smaller with its narrow distribution as the concentration of KOH increased up to 10 wt %. However, it came to be larger at this concentration and above. By adding small amount of Sr that would not affect that crystallinity of particles we can improve dielectric property of sintered materials. Addition of Zr may shift the major crystal phase of synthetic PSZT powder from tetragonal to rhombohedral phase.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.172-178
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• 2022

To investigate the feeding habits and trophic level of the blackthroat seaperch, Doederleinia berycoides in the South Sea of Korea, fish samples were collected by a bottom trawl net from fisheries resources survey vessels of NIFS in February, May, August and November 2021. The total length (TL) of these specimens was from 3.3 to 33.1 cm. D. berycoides fed majorly on Teleostei (especially Engraulis japonicus) based on index of relative importance (%IRI=64.4%). D. berycoides underwent an ontogenetic dietary shift. Smaller individuals (<10.0 cm TL) fed mainly on amphipods. The proportion of amphipods decreased as body size increased, whereas the consumption of Teleostei increased gradually. Examination of the feeding habits according to ontogentic feeding patterns in the diets of D. berycoides revealed that the mean weight of prey (mW/ST) continuously increased, while mean number of prey (mN/ST) decreased and then increased. The estimated average trophic level of the D. berycoides was 3.62±0.64, ranging from 3.31±0.52 to 3.79±0.70.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.347-353
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• 2023

Zenopsis nebulosa were collected by bottom trawl net from 20 areas in the South Sea of Korea during 2021 (February, May, August, November). The range of total length was 10.1~50.2 cm and empty stomach rate was 45.8%. The most important prey of Z. nebulosa was Pisces, with Trichiurus japonicus, Trachurus japonicus and Benthosema pterotum. And the second important prey was Euphausiacea. Z. nebulosa showed dietary shift by size class. In the <20.0 cm size class, Trachurus japonicus was dominant prey item. In the 20.0~25.0 cm size class, Trichiurus japonicus was dominant prey item. In the ≥25.0 cm size class, B. pterotum was dominant prey item. Analysis of the mean weight of preys per stomach (mW/ST) increased with individual size.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.179-195
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• 2002

The purpose of this research is to provide a proper model by analyzing the sports biomechanical of physical movements on the basis of the two patterns(open-stance and cross-stance) at the ready-to-start pose. The subjects for this study are composed of five male handball players from P university and five female shooting players from S university. Three-way moving actions at start(right, left, and forward) are recorded with two high-speed video cameras and measured with two Force platforms and a EMG system. Three-dimensional action analyzer, GRF system, and Whole body reaction movement system are used to figure out the moving mechanisms at the start pose. The analytic results of the moving mechanism at the start pose were as follows. 1. Through examining the three-way moving actions at start, I have found the cross-stance pose is better for the moving speed of body weight balance than the open-stance one. 175 degree of knee joint angle at "take-off" and 172 degree of hip joint angle were best for the start pose. 2. The Support time and GRF data shows that the quickest center of gravity shift was occurred when cross-stanced male subjects started to move toward his lefthand side. The quickest male's average supporting time of left and right foot is 0.19${\pm}$0.07 sec., 0.26${\pm}$0.06sec. respectively. The supporting time difference between two feet is 0.07sec. 3. Through analyzing GRF of moving actions at start pose, I have concluded that more than 1550N are overloaded on one foot at the open-stance start, and the overloaded force may cause physical injury. However, at the cross-stance pose, The GRF are properly dispersed on both feet, and maximum 1350N are loaded on one foot.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.613-620
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• 2008

The genetic parameters used in National Hanwoo Genetic Evaluation(NHGE) were needed to be monitored and updated periodically for accounting any possible changes in population parameters due to selection and environmental changes. Genetic parameters were estimated with single and two-trait models with MTDFREML package using 2,791 carcass records of steers collected from Hanwoo Progeny Test Program(HPTP). Single and two-trait models gave similar parameter estimates for all traits. The heritability estimates from single and two-trait models for carcass weight(CW), dressing percentage(DP), eye muscle area(EMA), back fat thickness(BFT) and marbling score(MS) were 0.30, 0.30, 0.37, 0.44 and 0.44, respectively. The heritability estimates for all the traits except BFT were slightly lower than those used in NHGE but seemed to be within the acceptable ranges. However, further monitoring is needed because the data might not have fully reflected the changes such as carcass grading standards in performance testing program. In order to shift statistical model of NHGE from single trait model to multiple-trait model, the genetic correlations between carcass traits were estimated with pairwise two-trait models. The genetic correlation coefficients between CW and DP, between CW and EMA, between CW and BFT and between CW and MS were 0.44, 0.63, 0.17 and 0.06, respectively. Those between DP and EMA, between DP and BFT and between DP and MS were 0.29, 0.40 and 0.20. Those between EMA and BFT and between EMA and MS were －0.24 and 0.15, respectively. The genetic correlation coefficient between BFT and MS was 0.03.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.2
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• pp.124-134
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• 2005

To investigate the exposure effect of polynuclear aromatic hydrocarbons (PAHs), we measured airborne total PAHs as an external dose, urinary 1-hydroxypyrene (1-OHP) as an internal dose of PAHs exposure, and analyzed the relationship between urinary 1-OHP concentration and PAHs exposure. The study population contained 44 workers in steel-pipe coating and paint manufacture industries. The airborne PAHs was obtained during survey day, and urine were sampled at the end of shift. Personal information on age, body weight, height, eniployment duration, smoking habit, and alcohol consumption was obtained by a structured questionnaire. Airborne PAHs were analyzed by the gas chromatograph with mass selective detector. Urinary 1-OHP levels were analyzed by the high performance liquid chromatograph with ultraviolet wavelength detector. For statistical estimation, t-test, ${\chi}^2$-test, analysis of variance, correlation analysis, arid regression analysis were executed by SPSS/PC (Windows version 10). The mean of environmental total PAHs was $87.8{\pm}7.81{\mu}g/m^3$. The mean concentration ($526.5{\pm}2.85{\mu}g/m^3$) of workers in steel-pipe coating industries using coal tar enamel was the higher than that ($17.5{\pm}3.36{\mu}g/m^3$) of workers in paint manufacture industries using coal tar paint. The mean of urinary 1-OHP concentration ($51.63{\pm}3.144{\mu}\;mol/mol$ creatinine) of workers in steel-pipe coating industries was the higher than that ($2.33{\pm}4.709{\mu}\;mol/mol$ creatinine) of workers in paint manufacture industries. The mean of urinary 1-OHP concentration of smokers was the higher than that of non-smokers. There was significant correlation between the urinary concentration of 1-OHP and the environmental concentration of PAHs (r=O.S48, p<0.001), pyrene(r=0.859, p<0.001), and urinary cotinine (r=0.324, p<0.05). The regression equation between the urinary concentration of 1-OHP in ${\mu}g/g$ creatinine($C_{1-OHP}$) and airborne concentration of PAHs (or pyrene) in ${\mu}g/m^3$ ($C_{PAHs}$ or Cpyrene) is: Log ($C_{1-OHP}$)=-0.650+0.889×Log($C_{PAHs}$), where $R^2=0.694$ and n=38 for p<0.001.Log ($C_{1-OHP}$)=1.087+0.707${\times}$Log(Cpyrene), where $R^2=0.713$ and n=38 for p<0.001. From the results of stepwise multiple regression analysis about 1-OHP, significant independents were total PAHs and urinary cotinine (adjusted $R^2=0.743$, p<0.001). In this study, there were significant correlation between the urinary concentration of 1-OHP and the airborne concentration of PAHs. The urinary 1-OHP was effective index as a biomarker of airborne PAHs in workplace. But it was influenced by non-occupational PAHs source, smoking.

• KDI Journal of Economic Policy
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• v.32 no.4
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• pp.153-195
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• 2010

The recent global financial crisis has been the outcome of, among other things, the mismatch between institutions and the reality of the market in the current global financial system. The International financial institutions (IFIs) that were designed more than 60 years ago can no longer effectively meet the challenges posed by the current global economy. While the global financial market has become integrated like a single market, there is no international lender of last resort or global regulatory body. There also has been a rapid shift in the weight of economic power. The share of the Group of 7 (G7) countries in global gross domestic product (GDP) fell and the share of emerging market economies increased rapidly. Therefore, the tasks facing us today are: (i) to reform the IFIs -mandate, resources, management, and governance structure; (ii) to reform the system such as the international monetary system (IMS), and regulatory framework of the global financial system; and (iii) to reform global economic governance. The main focus of this paper will be the IMS reform and the role of the Group of Twenty (G20) summit meetings. The current IMS problems can be summarized as follows. First, the demand for foreign reserve accumulation has been increasing despite the movement from fixed exchange rate regimes to floating rate regimes some 40 years ago. Second, this increasing demand for foreign reserves has been concentrated in US dollar assets, especially public securities. Third, as the IMS relies too heavily on the supply of currency issued by a center country (the US), it gives an exorbitant privilege to this country, which can issue Treasury bills at the lowest possible interest rate in the international capital market. Fourth, as a related problem, the global financial system depends too heavily on the center country's ability to maintain the stability of the value of its currency and strength of its own financial system. Fifth, international capital flows have been distorted in the current IMS, from EMEs and developing countries where the productivity of capital investment is higher, to advanced economies, especially the US, where the return to capital investment is lower. Given these problems, there have been various proposals to reform the current IMS. They can be grouped into two: demand-side and supply-side reform. The key in the former is how to reduce the widespread strong demand for foreign reserve holdings among EMEs. There have been several proposals to reduce the self-insurance motivation. They include third-party insurance and the expansion of the opportunity to borrow from a global and regional reserve pool, or access to global lender of last resort (or something similar). However, the first option would be too costly. That leads us to the second option - building a stronger globalfinancial safety net. Discussions on supply-side reform of the IMS focus on how to diversify the supply of international reserve currency. The proposals include moving to a multiple currency system; increased allocation and wider use of special drawing rights (SDR); and creating a new global reserve currency. A key question is whether diversification should be encouraged among suitable existing currencies, or if it should be sought more with global reserve assets, acting as a complement or even substitute to existing ones. Each proposal has its pros and cons; they also face trade-offs between desirability and political feasibility. The transition would require close collaboration among the major players. This should include efforts at the least to strengthen policy coordination and collaboration among the major economies, and to reform the IMF to make it a more effective institution for bilateral and multilateral surveillance and as an international lender of last resort. The success on both fronts depends heavily on global economic governance reform and the role of the G20. The challenge is how to make the G20 effective. Without institutional innovations within the G20, there is a high risk that its summits will follow the path of previous summit meetings, such as G7/G8.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.347-355
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• 1999

Background: Phospholipase C(PLC) plays a central role in cellular signal transduction and is important in cellular growth, differentiation and transformation. There are currently ten known mammalian isozymes of PLC reported to this date. Hydrolysis of phosphatidylinositol 4,5-bisphosphate($PIP_2$) by PLC produces two important second messengers, inositol 1,4,5-trisphosphate($IP_3$) and diacylglycerol. PLC-${\gamma}1$, previously, was known to be activated mainly through growth factor receptor tyrosine kinase. Other mechanisms of activating PLC-yl have been reported such as activation through tau protein in the presence of arachidonic acid in bovine brain and activation by $IP_3$, phosphatidic acid, etc. Very recently, another PLC-${\gamma}1$ activator protein such as tau has been found in bovine lung tissue, which now is considered to be AHNAK protein. But there has been no report concerning AHNAK and its associated disease to this date. In this study, we examined the expression of the PLC-${\gamma}1$ activator, AHNAK, in lung cancer specimens and their paired normal. Methods: From surgically resected human lung cancer tissues taken from twenty-eight patients and their paired normal counterparts, we evaluated expression level of AHNAK protein using immunoblot analysis of total tissue extract Immunohistochemical stain was performed with primary antibody against AHNAK protein. Results: Twenty-two among twenty-eight lung cancer tissues showed overexpression of AHNAK protein (eight of fourteen squamous cell lung cancers, all of fourteen adenocarcinomas). The resulting bands were multiple ranging from 70 to 200 kDa in molecular weight and each band was indistinct and formed a smear, reflecting mobility shift mainly due to proteolysis during extraction process. On immunohistochemistry, lung cancer tissues showed a very heavy, dense staining with anti-AHNAK protein antibody as compared to the surrounding normal lung tissue, coresponding well with the results of the western blot Conclusion: The overexpression of PLC-${\gamma}1$ activator protein, AHNAK in lung cancer may provide evidence that the AHNAK protein and PLC-${\gamma}1$ act in concerted manner in carcinogenesis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.210-219
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• 2021

In recent years, air temperature has been increasing rapidly compared to the 1980s because of global warming. This increase in temperature reduces the yield and quality of rice; therefore, measures are needed to prevent such effects and ensure food security. The early maturing type (EMT) of rice is mainly cultivated in the central northern mid-mountainous area (CNMA). This study was conducted to shift the transplanting date of EMT and to examine the adaptability of the mid-maturing type (MMT) or mid-late maturing type (MLMT) in the Jecheon region of the CNMA to address global warming. The air temperature increased by 0.7-0.9℃ in the 2010s, compared to that in the 1980s, and was similar to other decades during the ripening period. Over the past 35 years, considering rice quality, the heading date of the Odae variety has arrived sooner by approximately 10 days, the ripened grain ratio has increased by more than 10%, and the thousand grain weight; however, the mean temperature at 40 days after heading has increased by more than 2℃. The late marginal heading date in the Jecheon region was determined as August 11 based on the accumulated temperature of 880℃ and August 15 based on 840℃ for 40 days after heading. According to different transplanting dates, milled rice yield per 10 a was the highest at 567 kg with June 10 in EMT, 595 kg with June 10 in MMT, and 572 kg with May 30 in MLMT. Considering the late marginal heading date, rice yield, and quality, the optimum transplanting date was June 15 in EMT, June 5 in MMT, and May 30 in MLMT in the Jecheon region of CNMA. Owing to global warming, MMT and MLMT are expected to be reliably cultivated in the CNMA.