• Wind and Structures
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• v.20 no.2
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• pp.327-347
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• 2015

This paper investigates the effects of Reynolds number (Re) on the aerodynamic characteristics of a twin-deck bridge. A 1:36 scale sectional model of a twin girder bridge was tested using the Wall of Wind (WOW) open jet wind tunnel facility at Florida International University (FIU). Static tests were performed on the model, instrumented with pressure taps and load cells, at high wind speeds with Re ranging from $1.3{\times}10^6$ to $6.1{\times}10^6$ based on the section width. Results show that the section was almost insensitive to Re when pitched to negative angles of attack. However, mean and fluctuating pressure distributions changed noticeably for zero and positive wind angles of attack while testing at different Re regimes. The pressure results suggested that with the Re increase, a larger separation bubble formed on the bottom surface of the upstream girder accompanied with a narrower wake region. As a result, drag coefficient decreased mildly and negative lift coefficient increased. Flow modification due to the Re increase also helped in distributing forces more equally between the two girders. The bare deck section was found to be prone to vortex shedding with limited dependence on the Re. Based on the observations, vortex mitigation devices attached to the bottom surface were effective in inhibiting vortex shedding, particularly at lower Re regime.

• Journal of Ginseng Research
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• v.4 no.1
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• pp.55-64
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• 1980

The distribution pattern of mineral nutrients, among various Parts of Korea ginseng (Panax ginseng C.A. Meyer) was investigated to understand ginseng nutrition by simple correlation analysis. Five·year old ginseng plants grown under four different nutritional environments were sampled and separated into leaf, petiole, stem, rhizome, cortex and epidermis of tap foot, central part of tap root, cortex and epidermis of lateral root, central part of lateral root, fine root in the middle of truly, for chemical analysis. Between mineral nutrients in root, N and P showed highly significant positive correlation each other and with Mg and Cu while all other elements (K, Ca, Mg, Fe, Mn, Zn, Cu, B) showed highly significant positive correlation each other. In shoot, number of mineral nutrient pairs haying significant relation was much less than in root. (Negative: P with Ca or B, K with N, Fe, Mn or Cu, Positive: N with Mg, Fe, Mn or Cu, K with Zn, Ca with Mg, Zn, or B, Fe Mn Cu each other, Mn with B.) The number of pairs having significant correlation in whole plant was approximately the same as the number in root but three of them showed significant negative correlation. The distribution pattern similarity of mineral contents among various parts was also discussed in relation to physiological significance in Korea ginseng plant.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.873-880
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• 2021

The purpose of this study is to investigate the impact of internal control on credit risk of joint stock commercial banks in Vietnam from 2007 to 2018. Furthermore, we specify bank-specific characteristics and macroeconomic conditions, and analyze how these factors affect credit risk of banks: the number of board members, the number of board members with banking or finance background as ratio of total board members, loans to total assets ratio, loans to deposit ratio, the number of days between the year-end and the publication of the financial statements, and the use of top four auditing firms proxy for five elements of internal control. By using the dataset of 30 Vietnamese joint stock commercial banks and Bayesian linear regression via Random-walk Metropolis Hastings algorithm, the results of this study show that five elements of internal control have a impact on bank credit risk, namely, control environment, risk assessment, control activities, information and communication, and monitoring activities. For factors of banks' characteristics, bank size and financial leverage have a negative impact on banks' credit risk, and bank age has a positive effect. For macroeconomic factors, inflation has a positive impact and economic growth has a negative impact on banks' credit risk.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.3
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• pp.327-335
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• 2022

The purpose of this study is to examine the Kuwaiti Stock Exchange's (KDE) response to the COVID-19 pandemic and the precautions taken by Kuwaiti authorities to protect their citizens and other residents. To achieve this objective, daily data from four different indexes published by the Kuwait Stock Exchange (KSE) for the period between 24 February and 30 June 2020, as well as daily data on the number of people infected with COVID-19, the daily number of recovered people, the daily number of deaths, lockdown days, and days the country was under curfew. The findings show a significant positive association between the daily recovery of persons infected by COVID-19 and all indexes published by the KSE except for the Boursa Kuwait Main Market 50, where the association was positive but insignificant. A negative and significant association was also found between the closure of the country and each of the four indexes. Although the curfew imposed by the Kuwaiti authorities at an early stage of the pandemic appeared to have a negative effect on the four indexes, the level of association was statistically significant only in the cases of the Main Market index and Boursa Kuwait Main Market 50 index.

• Archives of Plastic Surgery
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• v.35 no.2
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• pp.223-228
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• 2008

Purpose: V.A.C. is a new concept which is closed dressing with negative pressure to promote wound healing. It has been widely used as the treatment of chronic and acute wounds such as pressure sores, burns, stasis ulcers, and other complicated wounds. However It has disadvantages such as high cost and the need of specific equipment. In this article, we described new method to overcome these disadvantages. Methods: We made newly innovated equipment with 50 cc syringe and spring to create negative pressure. From May 2006 to May 2007, we applied it to two patients with chronic wound. Results: The treatment period was 5 weeks for one case and 3 weeks for the other case. Both patients were healed completely without admission and wound healing was accelerated. During follow-ups, there were no complications. The mean cost for single dressing was 9,590 won. Conclusion: Modified portable negative therapy using newly innovated equipment could accelerate wound healing better than conventional dressing. It lowers the number of dressings, saves cost of treatment, and enables treatment as outpatient basis.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.103-110
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• 2011

This study deals with the traffic accidents by type. The objectives are to analyze the characteristics of 2 accident types, and to develop the models by type. In pursuing the above, this paper gives particular attentions to testing the differences between by type two groups, and developing the models (Poisson and negative binomial regressions) using the data of domestic circular intersections. The main results are as follows. First, the number of accidents in vehicle vehicle was analyzed to account for about 73.41% of total and to be higher than vehicle people. Second, two Poisson models and two negative binomial models which were all statistically significant were developed using vehicle people accidents and vehicle vehicle accidents as dependant variables. Finally, the traffic volume as common variable was selected in the models, and right-turn slip lane, speed hump, the number of driveways, the number of pedestrian crossings as specific variables of the models were selected.

• Health Policy and Management
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• v.26 no.4
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• pp.343-351
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• 2016

Background: This study aims to analyze the effects of insurance types on the medical service uses for heart failure inpatients using propensity score matching (PSM). Methods: 2014 National inpatient sample based on health insurance claims data was used in the analysis. PSM was applied to control factors influencing the service uses except insurance types. Negative binomial regression was used after PSM to analyze factors that had influences on the service uses among inpatients. Subjects were divided by health insurance type, national health insurance (NHI) and medical aid (MA). Total charges and length of stay were used to represent the medical service uses. Covariance variables in PSM consist of sociodemographic characteristics (gender, age, Elixhauser comorbidity index) and hospital characteristics (hospital types, number of beds, location, number of doctors per 50 beds). These variables were also used as independent variables in negative binomial regression. Results: After the PSM, length of stay showed statistically significant difference on medical uses between insurance types. Negative binomial regression provided that insurance types, Elixhauser comorbidity index, and number of doctors per 50 beds were significant on the length of stay. Conclusion: This study provided that the service uses, especially length of stay, were differed by insurance types. Health policy makers will be required to prepare interventions to narrow the gap of the service uses between NHI and MA.

• Journal of the Mineralogical Society of Korea
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• v.13 no.4
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• pp.186-195
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• 2000

To study phosphate adsorption on kaolinite, $^{31}$ P MAS NMR(magic angle spinning nuclear magnetic resonance spectroscopy)has been used for kaolinite reacted in 0.1 M phosphate solutions at pH’s from 3 to 11. There are at least 3 different forms of phosphate on kaolinite. One is the phosphate physically adsorbed on kaolinite surface (outer-sphere complexes) or species left after vacuum-filtering. The second is the phosphate adsorbed by ligand exchange (inner-sphere complexes), and the third is Al-phosphate precipitates which are pH dependent. Most of the inner-spherer complexes and surface precipitates are mainly on hydroxided Al(aluminol) rather than hydroxided Si(silanol). These are pertinent with the results obtained from the phosphate adsorption experiments on silica gel and ${\gamma}$-Al$_2$O$_3$ as model compounds, respectively. The two peaks with more negative chemical shifts(more shielded) than the ortho-phosphate peak (positive chemical shift) are assigned to be the inner-sphere complexes and surface precipitates. The $^{31}$ P chemical shifts of the Al-phosphate precipitates are more negative than those of inner-sphere complexes at a given pH due to the larger number of P-O-Al linkages per tetrahedron. The chemical shifts of both the inner-sphere complexes and surface precipitates are more negative than those of inner-sphere complexes at a given pH due to the larger number of P-O-Al linkages per tetrahedron. The chemical shifts of both the inner-sphere complexes and surface precipitates become progressively less shielded with increasing pH. For the inner-sphere complexes, decreasing phosphate protonation combined with peak averaging by rapid proton exchange among phosphate tetrahedra with different numbers of protons is though to be the reason for the peak change. The decreasing shielding with increasing pH for surface precipitates is probably due to the decreasing average number of P-O-Al linkages per tetrahedron combined with decreasing protonation like inner-sphere complexes.

• International Journal of Contents
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• v.8 no.3
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• pp.1-6
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• 2012

This study establishes a simple Causal Map in order to understand the structure of Social Network Services(SNS). From this, the paper proposes a simulation with drawing Simulation Model and it examines whether a Dunbar Number is available for the emergence of collective intelligence based on an on-line network. Through my analytical research, it turn out both Closed SNS and Open SNS have their own Dunbar Number. However, it appear that Open SNS can expand infinitely as it has a unique property namely weak tie. This implies that it is significant for a system or policy to be developed in order to overcome the problem of Dunbar Number, whereas restricting the extension of a network by considering the Dunbar Number would have a negative impact on emergence of collective intelligence.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.335-340
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• 2015

Using the Total Electron Content (TEC) data from the Global Navigation Service System (GNSS) site in Jeju, operated by the Korea Astronomy and Space Science Institute (geographic location: $33.3^{\circ}N$, $126.5^{\circ}E$; geomagnetic location: $23.6^{\circ}N$) for 2002-2014 in Korea, the results of the statistical analysis of positive and negative ionospheric storms are presented for the first time. In this paper, ionospheric storms are defined as turbulences that exceed 50% of the percentage differential Global Positioning System (GPS) TEC ratio (${\Delta}TEC$) with monthly median GPS TEC. During the period of observations, the total number of positive ionospheric storms (${\Delta}TEC$ > 50%) was 170, which is greater than five times the number of negative ionospheric storms (${\Delta}TEC$ < - 50%) of 33. The numbers of ionospheric storms recorded during solar cycles 23 and 24 were 134 and 69, respectively. Both positive and negative ionospheric storms showed yearly variation with solar activity during solar cycle 23, but during solar cycle 24, the occurrence of negative ionospheric storms did not show any particular trend with solar activity. This result indicates that the ionosphere is actively perturbed during solar cycle 23, whereas it is relatively quiet during solar cycle 24. The monthly variations of the ionospheric storms were not very clear although there seems to be stronger occurrence during solstice than during equinox. We also investigated the variations of GPS positioning accuracy caused by ionospheric storms during November 7-10, 2004. During this storm period, the GPS positioning accuracies from a single frequency receiver are 3.26 m and 2.97 m on November 8 and 10, respectively, which is much worse than the quiet conditions on November 7 and 9 with the accuracy of 1.54 m and 1.69 m, respectively.