• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.5
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• pp.785-794
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• 2015

To obtain low resistance and high efficiency energy-saving ship, minimum total resistance hull form design method is studied based on potential flow theory of wave-making resistance and considering the effects of tail viscous separation. With the sum of wave resistance and viscous resistance as objective functions and the parameters of B-Spline function as design variables, mathematical models are built using Nonlinear Programming Method (NLP) ensuring the basic limit of displacement and considering rear viscous separation. We develop ship lines optimization procedures with intellectual property rights. Series60 is used as parent ship in optimization design to obtain improved ship (Series60-1) theoretically. Then drag tests for the improved ship (Series60-1) is made to get the actual minimum total resistance hull form.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.304-308
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• 1994

Among the new series of phenylacetamides, one of capsaicin derivatives, KR-25018 was found to have a very potent analgesic activity. Thus, the phamacological properties of KR-25018 were compared with those of morphine, capsaicin, and nonsteroidal antiinflammatory drugs (NSAIDs). The analgesic activities were evaluated in several animal models, using different stimuli, such as phenylbenzoquinone(PBQ)-induced weithing test, tail-filck test in mice and adjuvant arthritic flexion test in rat. The relationship of phamacological properties of KR-25018 to that of centrally acting opioids was assessed by the blocking test using naloxone. The analgesic potency of the KR-25018 $(MPED_{50}=0.89{\;}p.o.{\;}in{\;}PBQ-induced{\;}weithing{\;}test, {\;}MPED_{50}$=0.61$ s.c. in tail-flick test in mice0, with different action mechanism from morphine and NSAIDs, was comparable to that of morphine.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.4
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• pp.1-10
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• 2004

In this paper we study bounds for characteristics of stationary waiting times in (max, +)-linear systems with a Poisson arrival process. which are prevalent in manufacturing systems, kanban systems, cyclic and acyclic fork-and-join type systems, finite or infinite capacity tandem queues with various kinds of blocking, transportation systems, and telecommunication networks, and so on. Recently, some results on series expansion for characteristics, such as higher moments, Laplace transform, and tail probability, of transient and stationary waiting times in a class of (max, +)-linear systems via Taylor series expansions have been studied. In order to overcome the computational complexity in those results, we consider bounds for characteristics of stationary waiting times using valuable stochastic ordering results. Some numerical examples are also provided.

• Wind and Structures
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• v.2 no.2
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• pp.85-94
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• 1999

The EARPG(1)/UPS was first developed by Seong (1993) and has been tested for wind pressure time series simulations (Seong and Peterka 1993, 1997, 1998) to prove its excellent performance for generating non-Gaussian time series, in particular, with large amplitude sharp peaks. This paper presents a parametric study focused on simulation of extreme value statistics based on the synthetic realizations of the EARPG(1)/UPS. The method is shown to have a great capability to simulate a wide range of non-Gaussian statistic values and extreme value statistics with exact target sample power spectrum. The variation of skewed long tail in PDF and extreme value distribution are illustrated as function of relevant parameters.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.987-998
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• 2013

This paper considers the statistical characteristics on the air quality (PM10) of Korea collected hourly in 2011. PM10 in Korea exhibits very strong correlations even for higher lags, namely, long range dependence. It is power-law tailed in marginal distribution, and generalized Pareto distribution successfully captures the thicker tail than log-normal distribution. However, slowly decaying autocorrelations may confuse practitioners since a non-stationary model (such as changes in mean) can produce spurious long term correlations for finite samples. We conduct a statistical testing procedure to distinguish two models and argue that the high persistency can be explained by non-stationary changes in mean model rather than long range dependent time series models.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.160-169
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• 2015

Three unrecorded species of free-living marine nematodes, belonging to genus Enoplus Dujardin, 1845 collected from rocky intertidal seagrass on the eastern coast of Korea, are described and illustrated. Enoplus taipingensis Zhang and Zhou, 2012 is characterized by longer body size, a series of lateral setae throughout the tail in male, the presence of trumpet-shaped precloacal supplement with well-dilated proximal end, and the presence of spicules with five to eight semicircular plates. Enoplus meridionalis Steiner, 1921 is characterized by the presence of trumpetshaped precloacal supplement with slightly dilated proximal end, paired massive spicules, and tail with two pairs of stout terminal setae. Enoplus mammillatus Timm, 1959 is easily distinguished from the congeners by narrow tubular-shaped precloacal supplement. In this study, we provide detailed morphological features of three Enoplus species by differential interference contrast microscopy and scanning electron microscopy. This is the first report on the species of the genus Enoplus from the Korean waters.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.2
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• pp.133-140
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• 2012

In this paper, we suggest a lifelike pattern generator for a quadruped walking system with a head, a tail, four legs and a torso. The system looks like a giant dinosaur which stands over 7 meters tall with its legs over 2 meters long. We focus on its lifelike naturalness. Thus, generating logical patterns in harmony with head-body-tail patterns and quadrupedal locomotion patterns makes you feel that the quadruped walking system is alive. The basic patterns of four legs and a body are obtained from a 3D graphic animation, which is made and captured from various motions of similar species in existence since the giant dinosaurs are exterminated. The dinosaur-like mechanism also is designed from bone and joint structures of quadrupedal animals. The lifelike pattern generator based on fuzzy logic could generate lifelike motions according to the dinosaur-like mechanism and the basic patterns. A series of computer simulations and experimental implements show that the pattern generator makes the quadruped walking system lifelike.

• East Asian Economic Review
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• v.24 no.3
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• pp.253-273
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• 2020

This paper investigates the impact of the effective minimum wage, defined as the log difference between the minimum and the median wages, on wage inequalities in the OECD countries. Unlike the previous studies that focus on single countries in which the minimum wage has no cross-sectional variation and rely instead on within-country variations of wage distribution across regions or socio-economic characteristics, we use a country panel that allows for both cross-sectional and time-series variations in minimum wage. We also control for more factors than in the previous studies whose absence may cause endogeneity. Our results confirm the previous findings that increases in minimum wage alleviate the wage inequality at the lower tail of the wage distribution, while having little effect at the upper tail. The estimated effect is larger for women than for men, which is consistent with the fact that the share of workers who are directly affected by the changes in minimum wage is bigger among women than men. An application of the IVs of Autor, Manning and Smith (2016) supports the robustness of our findings.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.265-281
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• 2017

For shallow tunnel constructions, settlement of the ground surface is a main issue. Recent technical developments in shield TBM tunneling technique have enabled a decrease in such settlements based on tunneling with ground deformation controls. For this objective, the tail void grouting is a common practice. Generally surface settlements in a soil of low permeability occur during a tunnel construction but also during a long period after completion of the tunnel. The long-term settlements occur mainly due to consolidation around the tunnel. The consolidation process is caused and determined by the tail void grouting which leads to an excess pore water pressure in the vicinity of the tunnel. Because of this, the grouting pressure has a strong effect on the long-term settlements in the shield tunneling. In order to investigate this effect, a series of coupled hydro-mechanical 3D finite element simulations have been performed. The results show that an increase in grouting pressure reduces the short-term settlements, but in many cases, it doesn't lead to a reduction of the final settlements after the completion of consolidation. Thereby, the existence of a critical grouting pressure is identified, at which the minimal settlements are expected.

• Journal of Electrical Engineering and Technology
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• v.6 no.4
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• pp.505-512
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• 2011

A novel passive boost power converter forsingle-phaseswitched reluctance motor is presented. A simple passive circuit is proposed comprisingthree diodes and one capacitor. The passive circuitis added in the front-end of a conventional asymmetric converter to obtain high negative bias. Based on this passive network, the terminal voltage of the converter side is a general DC-link voltage level in parallel mode up to a double DC-link voltage level in series mode. Thus,it can suppress the negative torque generation from the tail current and improve the output power. The results of the comparative simulation and experiments forthe conventional and proposed converter verify the performance of the proposed converter.