• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.385-391
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• 2022

In this study, a multivariate time series analysis was conducted to identify various variables that impact ocean freight rates in addition to supply and demand factors. First, we used the ClarkSea Index, Clarksons Average Bulker Earnings, and Clarksons Average Tanker Earnings provided by the Shipping Intelligence as substitute variables for the dependent variable, ocean freight. The following ndependent variables were selected: World Seaborne Trade, World Fleet, Brent Crude Oil Price, World GDP Growth Rate, Industrial Production (IP OECD) Growth Rate, Interest Rate (US$ LIBOR 6 Months), and Inflation (CP I OECD) through previous studies. The time series data comprise annual data (1992-2020), and a regression analysis was conducted. Results of the regression analysis show that the World Seaborne Trade and Brent Crude Oil P rice impacted the ClarkSea Index. Only the World Seaborne Dry Bulk Trade impacted the Clarksons Average Bulker Earnings, World Seaborne Oil Trade, Brent Crude Oil Price, IP, and CP I on the Clarksons Average Tanker Earnings.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.2
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• pp.121-128
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• 2003

This study was conducted to investigate the effect of tall type mixtures and tall+short type mixtures on dry matter yield, botanical composition and quality. The experimental design includes two mixture types: Tall type mixtures(TM); orchardgrass(Potomac) 40+tall fescue(Fawn) 20+Festulolium braunii (Paulita) 10+perennial ryegrass(Reveille) 10+timothy(Climax) 10+red clover(Kenland) 5+alfalfa(Vernal) 5%) and tall+short type mixtures(TSM); orchardgrass(Potomac) 40+tall fescue(Fawn) 20+Kentucky bluegrass(Newport, turf type) 10+redtop(Barricuda, turf type) 10+perennial ryegrass(Palmer III, turf type) 10+red fescue(Flyer II, turf type) 5+white clover(Regal) 5%. The dry matter(DM) yield was higher obtained in TSM than that of TM, but there was no significant difference between TM and TSM. In the chemical composition, there was no significant difference between TM and TSM, but the content of cellulose, lignin were higher in TM than those in TSM(p<0.05). Also, the content of acid detergent fiber which affected dry matter digestibility was higher in TM than that of TSM. The crude protein dry matter yield was not observed significant difference between TM and TSM, but digestible dry matter(DDM) yield was higher in TSM than that of TM. In botanical composition, tall fescue, alfalfa and orchardgrass were highly maintained in TM but white clover, tall fescue and orchardgrass were highly, and redtop, red fescue were continuously maintained in TSM. In this experiment, DM yields and quality of two mixture types were no difference. However, the tall+short type mixtures(TSM) were more effective in enhancing the dry matter digestibility and DDM yield, and in maintaining the various botanical composition.

• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.32-36
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• 2007

When the vacuum system for the process of $SiH_{4}$ gas used in the semiconductor and FPD field is partially vented from vacuum to atmospheric state, a fire often occurs due to auto-ignition of $SiH_{4}$ gas. In order to prevent the fire, the concentration of $SiH_{4}$ should be kept under LFL. This means that the higher capacity pump is needed to meet the process conditions as well as the condition that the concentration of $SiH_{4}$ should be kept under LFL. In this article, we conducted the injection of the dilution gas at the manifold between booster pump and dry pump compared with the typical method that the dilution gas was injected into inlet port of booster pump using computer simulation. According to the result, we can flow further more purge gas for safety without any change of the condition in the process chamber, which means that the higher capacity pump is not required for safety in some cases.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1778-1780
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• 2004

Microwave heating system of KSTAR consists of ECH and LHCD. ECH and LHCD offer the reliability of operation in the beginning of plasma formation and non-inductive current drive for long time steady state operation with maintaining MHD stability, respectively. LHCD demands 5 GHz of frequency and consists of c-band waveguide, 4-port circuitor, dry dummy load, dual directional coupler, E-bend, arc detector. Our system is a lineup type pulse modulator that has 45 kV of output pulse voltage, 90 A of pulse current, 4 us of pulse width. 1:4 step-up pulse transformer, 7 stages of PFN and thyratron tube (E2V, CX1191D) are used in this modulator. The purpose of this paper is to show the modulator design and experimental result.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.667-675
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• 2008

As a large construction such as highway, dam, reclaimed land etc. increase in number more and more, large amount of fill materials are required. However, it's difficult to obtain it because of environmental problems and economical efficiency. A alternative plan is to utilize a gypsum which is a by-product yielded from chemical plants and verify suitability to use gypsum as fill materials. Therefore, a characteristic of compaction for gypsum is analyzed and construction methods are given regard to this characteristic from construction of dike using gypsum. Based on the results obtained, it is found that moisture of gypsum in compaction should to be more dry side of O.M.C(optimal moisture content) because of sponge phenomenon. When gypsum is used to fill materials, standards of compaction should be decided from laboratory test.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1253-1253
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• 2001

The ability to accurately assess wine quality is important during the wine making process, particularly when allocating batches of wines to styles determined by consumer requirements. Grape payments are often determined by the quality category of the wine that is produced from them. Wine quality, in terms of sensory characteristics, is normally a subjective measure, performed by experienced winemakers, wine competition judges or winetasting panellists. By nature, such assessments can be biased by individual preferences and may be subject to day-to-day variation. Taste and aroma compounds are often present in concentrations below the detection limit of near infrared (NIR) spectroscopy but the more abundant organic compounds offer potential for objective quality grading by this technique. Samples were drawn from one of Australia's major wine shows and from BRL Hardy's post-vintage wine quality allocation tastings. The samples were scanned in transmission mode with a FOSS NIR Systems 6500, over the wavelength range 400-2500 ㎚. Data analysis was performed with the Vision chemometrics package. With samples from the allocation tastings, the best correlations between NIR spectra and tasting data were obtained with dry red wines. These calibrations used loadings in the wavelengths related to anthocyanins, ethanol and possibly tannins. Anthocyanins are a group of compounds responsible for colour in red wines - restricting the wavelengths to those relating to anthocyanins produced calibrations of similar accuracy to those using the full wavelength range. This was particularly marked with Merlot, a variety that tends to have relatively lower anthocyanin levels than Cabernet Sauvignon and Shiraz. For dry white wines, calibrations appeared to be more dependent on ethanol characteristics of the spectrum, implying that quality correlated with fruit maturity. The correlations between NIR spectra and sensory data obtained using the wine show samples were less significant in general. This may be related to the fact that within most classes in the show, the samples may span vintages, glowing areas and winemaking styles, even though they may be made from only one grape variety. For dry red wines, the best calibrations were obtained with a class of Pinot Noir - a variety that tends to be produced in limited areas in Australia and would represent the least matrix variation. Good correlations were obtained with a tawny port class - these wines are sweet, fortified wines, that are aged for long periods in wooden barrels. During the ageing process Maillard browning compounds are formed and the water is lost through the barrels in preference to ethanol, producing “concentrated” darkly coloured wines with high alcohol content. These calibrations indicated heaviest loadings in the water regions of the spectrum, suggesting that “concentration” of the wines was important, whilst the visible and alcohol regions of the spectrum also featured as important factors. NIR calibrations based on sensory scores will always be difficult to obtain due to variation between individual winetasters. Nevertheless, these results warrant further investigation and may provide valuable Insight into the main parameters affecting wine quality.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.161-173
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• 2021

The shipping industry plummeted and was depressed due to the global economic crisis caused by the bankruptcy of Lehman Brothers in the US in 2008. In 2020, the shipping market also suffered from a collapse in the unstable global economic situation due to the COVID-19 pandemic, but unexpectedly, it changed to an upward trend from the end of 2020, and in 2021, it exceeded the market of the boom period of 2008. According to the Clarksons report published in May 2021, the decrease in cargo volume due to the COVID-19 pandemic in 2020 has returned to the pre-corona level by the end of 2020, and the tramper bulk carrier capacity of 103~104% of the Panamax has been in the ports due to congestion. Earnings across the bulker segments have risen to ten-year highs in recent months. In this study, as factors affecting BDI, the capacity and congestion ratio of Cape and Panamax ships on the supply side, iron ore and coal seaborne tonnge on the demand side and Granger causality test, IRF(Impulse Response Function) and FEVD(Forecast Error Variance Decomposition) were performed using VAR model to analyze the impact on BDI by congestion caused by strengthen quarantine at the port due to the COVID-19 pandemic and the loading and discharging operation delay due to the infection of the stevedore, etc and to predict the shipping market after the pandemic. As a result of the Granger causality test of variables and BDI using time series data from January 2016 to July 2021, causality was found in the Fleet and Congestion variables, and as a result of the Impulse Response Function, Congestion variable was found to have significant at both upper and lower limit of the confidence interval. As a result of the Forecast Error Variance Decomposition, Congestion variable showed an explanatory power upto 25% for the change in BDI. If the congestion in ports decreases after With Corona, it is expected that there is down-risk in the shipping market. The COVID-19 pandemic occurred not from economic factors but from an ecological factor by the pandemic is different from the past economic crisis. It is necessary to analyze from a different point of view than the past economic crisis. This study has meaningful to analyze the causality and explanatory power of Congestion factor by pandemic.

• Journal of Korea Port Economic Association
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• v.27 no.1
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• pp.263-280
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• 2011

The global financial crisis, triggered by the subprime mortgage crisis in 2007, has put the world economy into the recession with financial market turmoil. I tested whether variables were cointegrated or whether there was an equilibrium relationship. Also, Generalized impulse-response function (GIRF) and accumulation impulse-response function (AIRF) may be used to understand and characterize the time series dynamics inherent in economical systems comprised of variables that may be highly interdependent. Moreover, the IRFs enables us to simulate the response in freight to a shock in the USD/JPY exchange rate, Dow Jones industrial average index, Dow Jones volatility, Chinese Import volatility. The result on the cointegration test show that the hypothesis of no cointergrating vector could be rejected at the 5 percent level. Also, the empirical analysis of cointegrating vector reveals that the increases of USD/JPY exchange rate have negative relations with freight. The result on the impulse-response analysis indicate that freight respond negatively to volatility, and then decay very quickly. Consequently, the results highlight the potential usefulness of the multivariate time series techniques accounting to behavior of Freight.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.2
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• pp.129-134
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• 2003

This study was conducted to investigate the effect of tall type mixtures(TM) and tall + short type mixtures(TSM) on nutritive utilization. DM intake, digestibility and utilization of nitrogen and energy of herbages from pastures by Korean native goats were determined. This experiment was conducted by total collection method in laboratory, 2000. The experimental herbage included two treatments: Tall type mixtures(orchardgrass, Potomac 40+tall fescue, Fawn 20+Festulolium braunii, Paulita 10+perennial ryegrass. Reveille 10+timothy, Climax 10+red clover, Kenblue 5+alfalfa, Vernal 5%), Tall+short type mixtures {orchardgrass, Potomac 40+tall fescue, Fawn 20+Kentucky bluegrass, New port(turf type) 10+redtop, Barricuda(turf type) 10+perennial ryegrass, Palmer III(turf type) 10+red fescue, Flyer II(turf type) 5+white clover, Regal 5%}. The voluntary dry matter(DM) intake of Korean native goats fed with herbages from tall+short type mixtures(TSM) was slightly higher than that of tall type mixtures(TM), but no difference was observed between TSM and TM(p > 0.05). The digestibility of DM, neutral detergent fiber, cellular contents and acid detergent fiber of herbage from TSM was slightly higher than that of TM, but no difference was detected between TSM and TM(p > 0.05). The utilization of nitrogen and energy by Korean native goats did not showed any difference in herbages from TSM and TM(p > 0.05). In conclusion, the herbage utilization by Korean native goats did not showed any significant difference. Thus, there is a possibility that turf grasses in mixtures can be used as a forage sources.

• Journal of Korea Port Economic Association
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• v.30 no.3
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• pp.1-14
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• 2014

This paper aims at measuring how new information is incorporated into volatility estimates. Various GARCH models are compared and estimated with daily BDI(Baltic Dry Index) data. While most researchers agree that volatility is predictable, they differ on how this volatility predictability should be modelled. This study, hence, introduces the asymmetric or leverage volatility models, in which good news and bad news have different predictability for future. We provide the systematic comparison of volatility models focusing on the asymmetric effect of news on volatility. Specifically, three diagnostic tests are provided: the sign bias test, the negative size bias test, and the positive size bias test. From the Ljung-Box test statistic for twelfth-order serial correlation for the level we do not find any significant serial correlation in the unpredictable BDI. The coefficients of skewness and kurtosis both indicate that the unpredictable BDI has a distribution which is skewed to the left and significantly flat tailed. Furthermore, the Ljung-Box test statistic for twelfth-order serial correlations in the squares strongly suggests the presence of time-varying volatility. The sign bias test, the negative size bias test, and the positive size bias test strongly indicate that large positive(negative) BDI shocks cause more volatility than small ones. This paper, also, shows that three leverage models have problems in capturing the correct impact of news on volatility and that negative shocks do not cause higher volatility than positive shocks. Specifically, the GARCH model successfully reveals the shape of the news impact curve and is a useful approach to modeling conditional heteroscedasticity of daily BDI.