• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.259-276
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• 2010

This study shows how Incheon will advance into roadmap as multi-transport hub in Northeast Asia hereafter and be proposed an urgent tasks and roles to construct a multi-transportation system for Incheon, which has both an international airport and port. The multi-transportation point of view of inter-major cities competitiveness of total scores was proposed 1. Shanghai(64.8 points), 2 in Hongkong(64.5), 3 in Incheon(62.9), and 4 in Busan(60.4) and Incheon was estimated to have enough competitiveness to be the international multi-transport hub in Northeast Asia. Sea & Air transportation revealed the most important multi-transportation in the Incheon region. In conclusion, this research suggests a development plan for multi-transportation in Incheon. Firstly, it proposes construction of sea & air transportation distribution center and agreement that simplifies logistic process between Incheon and Tianjin, secondly, suggests to activate project for the purpose of creating a better sea-land transportation system between Incheon and Shanghai.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.898-904
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• 2014

The stability of Bacillus licheniformis alpha-amylase (BLA) under acid condition was enhanced through direct evolution using the error-prone polymerase chain reaction. One beneficial mutation site, H281I, was obtained in BLA. The specific activity of H281I was 161/352 U/mg, which was 62.6/27.5% higher than that of the wild-type (WT) (99/276 U/mg) at pH 4.5/6.5 and $95^{\circ}C$. The pH optimum for H281I was decreased about 1 unit, whereas no significant changes of optimum temperature and thermostability were observed compared with the wild type (WT). The $k_{cat}/K_m$ value of H281I was 1.7-/1.4-fold higher at pH 4.5/6.5, respectively, than that of WT. The structure model analysis indicated that the H281I mutation altered the predicted interaction between the amino acid residues at 281 and 273, thus creating a conducive local environment for substrate binding, as reflected by its decreased $K_m$, and consequently increased the specific activity.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.111-119
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• 2020

This study takes Chinese independent tourists to South Korea as the research object, mines the data of tourists' digital footprints from online travel notes, and analyzes the characteristics of the tourism flow of Chinese independent tourists to South Korea by using the method of quantitative statistics and social network analysis(SNA). The results show that Seoul, Jeju Island, Busan and Daegu are the important tourist destinations for Chinese independent tourists entering South Korea. In addition, Qingdao, Tianjin, Shenyang, Hong Kong, Foshan and Macao are crucial hubs for Chinese independent tourists to visit South Korea. In future studies, the number of sample data should be increased. The time span of data collection should be extended for studying the annual variation characteristics of tourism flow and the trend of tourism hot spots.

• Membrane and Water Treatment
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• v.6 no.3
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• pp.205-224
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• 2015

A novel hydrophilic poly (vinylidene fluoride)/poly (p-phenylene terephthalamide) (PVDF/PPTA) blend membrane was prepared by in situ polycondensation of p-phenylene diamine (PPD) and terephthaloyl chloride (TPC) in PVDF solution with subsequent nonsolvent induced phase separation (NIPS) process. For comparison, conventional solution blend membrane was prepared directly by adding PVDF powder into PPTA polycondensation solution. Blend membranes were characterized by means of viscometry, X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM). The effects of different blending methods on membrane performance including water contact angle (WCA), mechanical strength, anti-fouling and anti-compression properties were investigated and compared. Stronger interactions between PVDF and PPTA in in situ blend membranes were verified by viscosity and XPS analysis. The incorporation of PPTA accelerated the demixing rate and caused the formation of a more porous structure in blend membranes. In situ blend membranes exhibited better hydrophilicity and higher tensile strength. The optimal values of WCA and tensile strength were $65^{\circ}$ and 34.1 MPa, which were reduced by 26.1% and increased by 26.3% compared with pure PVDF membrane. Additionally, antifouling properties of in situ blend membranes were greatly improved than pure PVDF membrane with an increasing of flux recovery ratio by 25%. Excellent anti-compression properties were obtained in in situ blend membranes with a stable pore morphology. The correlations among membrane formation mechanism, structure and performance were also discussed.

• Journal of Korea Port Economic Association
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• v.27 no.4
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• pp.271-289
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• 2011

Mongolia as a land-locked country, has tried to diversify its foreign trade with European and Asian countries. Recently continual price rise of mineral resources also helps Mongolia have chances to gain her trading partners. Nevertheless, regulations and barriers to exports of Mongolian mineral resources in China and Russia, which are transit countries, are complex and complicated in border crossing and transshipment procedures for transit transport. This paper discusses problems and barriers to economic and efficient logistics systems and transit transport of Mongolian mineral resources, and addresses a proposal of international intermodal transport corridors for improving transit transport, and suggests international cooperation, by applying transit rights of land-locked country. Specifically, it is necessary for Mongolia to search for other international intermodal corridors besides the corridor through the port of Tianjin. It is needed to build an international organization for discussion of affirmation of logistics equipments and improvement of transit procedure in border crossing, and to raise financial feasibility in building a new intermodal corridor.

• The Korean Journal of Pain
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• v.33 no.3
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• pp.216-225
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• 2020

Background: Garlic oil is a rich source of organosulfur compounds including diallyl disulfide and diallyl trisulfide. There have been studies showing the neuroprotective actions of these organosulfur compounds. However, the potential of these organosulfur compounds in neuropathic pain has not been explored. The present study was aimed at investigating the pain attenuating potential of diallyl disulfide and diallyl trisulfide in chronic constriction injury (CCI)-induced neuropathic pain in rats. The study also explored their pain-attenuating mechanisms through modulation of H₂S, brain-derived neurotrophin factor (BDNF) and nuclear factor erythroid 2-related factor 2 (Nrf2). Methods: The rats were subjected to CCI injury by ligating the sciatic nerve in four places. The development of neuropathic pain was measured by assessing mechanical hyperalgesia (Randall-Selittotest), mechanical allodynia (Von Frey test), and cold allodynia (acetone drop test) on 14th day after surgery. Results: Administration of diallyl disulfide (25 and 50 mg/kg) and diallyl trisulfide (20 and 40 mg/kg) for 14 days led to a significant reduction in pain in CCI-subjected rats. Moreover, treatment with these organosulfur compounds led to the restoration of H₂S, BDNF and Nrf2 levels in the sciatic nerve and dorsal root ganglia. Co-administration of ANA-12 (BDNF blocker) abolished pain attenuating actions as well as BDNF and the Nrf2 restorative actions of diallyl disulfide and diallyl trisulfide, without modulating H₂S levels. Conclusions: Diallyl disulfide and diallyl trisulfide have the potential to attenuate neuropathic pain in CCI-subjected rats possibly through activation of H₂S-BDNF-Nrf2 signaling pathway.

• The Pure and Applied Mathematics
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• v.16 no.4
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• pp.327-344
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• 2009

In this paper, we deal with the following system of nonlinear singular boundary value problems(BVPs) on time scale $\mathbb{T}$ $$\{{{{{{x^{\bigtriangleup\bigtriangleup}(t)+f(t,\;y(t))=0,\;t{\in}(a,\;b)_{\mathbb{T}},}\atop{y^{\bigtriangleup\bigtriangleup}(t)+g(t,\;x(t))=0,\;t{\in}(a,\;b)_{\mathbb{T}},}}\atop{\alpha_1x(a)-\beta_1x^{\bigtriangleup}(a)=\gamma_1x(\sigma(b))+\delta_1x^{\bigtriangleup}(\sigma(b))=0,}}\atop{\alpha_2y(a)-\beta_2y^{\bigtriangleup}(a)=\gamma_2y(\sigma(b))+\delta_2y^{\bigtriangleup}(\sigma(b))=0,}}$$ where $\alpha_i$, $\beta_i$, $\gamma_i\;{\geq}\;0$ and $\rho_i=\alpha_i\gamma_i(\sigma(b)-a)+\alpha_i\delta_i+\gamma_i\beta_i$ > 0(i = 1, 2), f(t, y) may be singular at t = a, y = 0, and g(t, x) may be singular at t = a. The arguments are based upon a fixed-point theorem for mappings that are decreasing with respect to a cone. We also obtain the analogous existence results for the related nonlinear systems $x^{\bigtriangledown\bigtriangledown}(t)$ + f(t, y(t)) = 0, $y^{\bigtriangledown\bigtriangledown}(t)$ + g(t, x(t)) = 0, $x^{\bigtriangleup\bigtriangledown}(t)$ + f(t, y(t)) = 0, $y^{\bigtriangleup\bigtriangledown}(t)$ + g(t, x(t)) = 0, and $x^{\bigtriangledown\bigtriangleup}(t)$ + f(t, y(t)) = 0, $y^{\bigtriangledown\bigtriangleup}(t)$ + g(t, x(t)) = 0 satisfying similar boundary conditions.

• Journal of Fashion Business
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• v.6 no.4
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• pp.113-124
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• 2002

The purpose on this study identified the purchasing conditions of Sports wear of the Chinese men residing in Beijing, Shanghai, Dalian, Tianjin, Harbin and Guangzhou, so that it helped sports wear manufacturers and retailers offer the basic data. For the study, a questionnaire used as a method of measurement, the 863 Chinese men were selected as a sample, SAS(Statistical Analysis System) program was used to analyze the data. The results from the study were as follows: 1. According to the investigation, the most preferred sports of Chinese men is soccer, as a whole. Swimming, basketball and ping-pong keep rank the next to soccer. 2. Accordingly age, area, profession and income, Chinese men maintained sports suit in order of training suit, swimming suit, soccer suit, tennis suit. It is found that holding amount of high-quality sports wears as ski, golf is on a low level. 3. It is appeared that Chinese men purchased in good order as follow brand: No-bran, Nike, Lening, Adidas. And except Nike, they purchased more Lening brand than foreign sports brand. 4. As the result of researching on the item of sports wear, it is found that they purchased various kind items in a higher rank 5 brands. 5. Sports wear's color that Chinese men purchased is blue, white, black, red. 6. The purchasing price that Chinese men favored is 200$\sim$599RMB. Thus, they expend average per head for sports suit buying, 486.0RMB. 7. Chinese men purchased very often at specialty store. And, coefficient of utilization at the usual market is on a low level. 8. In purchasing satisfaction, 80 % Chinese men were satisfied with goods(sports wear) that purchased in a higher rank 5 brands. So, average satisfaction degree showed over 3.8 as a high rate. 9. According to the result of satisfaction on Chinese men, 70% Chinese men showed satisfaction. Therefore, the average of satisfaction degree appeared 3.81 as a high rate.

• Membrane and Water Treatment
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• v.8 no.4
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• pp.311-321
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• 2017

Hydrophilic and high modulus PPTA molecules were incorporated into PVDF matrix via the in situ polymerization of PPD and TPC in PVDF solution. PPTA/PVDF/NWF blend membrane was prepared through the immersion precipitation phase inversion method and nonwoven coating technique. The membrane integrated technology including PPTA/PVDF/NWF blend membrane and reverse osmosis (RO) membrane was employed to treat the polyester/viscose spunlace nonwoven process wastewater. During the consecutive running of six months, the effects of membrane integrated technology on the COD, ammonia nitrogen, suspended substance and pH value of water were studied. The results showed that the removal rate of COD, ammonia nitrogen and suspended substance filtered by PPTA/PVDF blend membrane was kept above 90%. The pH value of the permeate water was about 7.1 and the relative water flux of blend membrane remained above 90%. After the deep treatment of RO membrane, the permeate water quality can meet the water circulation requirement of spunlace process.

• Journal of Korea Port Economic Association
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• v.31 no.2
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• pp.85-101
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• 2015

This study formulates a development strategy for Gwangyang port through the analysis of its competition with other major Northeast Asian ports. A revised BCG matrix is applied to estimate the change in competition between the major ports in Northeast Asia and the Lotka-Volterra model is used for the competitor analysis. The growing competitive power and influence of Chinese ports, continued competitive advantage of Busan port, diminishing competitiveness of Gwangyang and Incheon ports, and disappearing competitive position of Japanese ports in Northeast Asia are all confirmed. In addition, according to the relationship between Gwangyang port and other major Northeast Asian ports from 2007 to 2014, Gwangyang port has changed to a predatory from a win/win relation with Busan port and has maintained its predatory relationship with Hong Kong port in terms of transshipment cargoes. Moreover, Gwangyang port has formed predatory relationships with Shanghai and Ningbo ports, a pure competitive relation with Tianjin port, and a win/win relation with Qingdao and Dalian ports. Overall, predatory relationships between Gwangyang port and other Northeast Asia ports increased from 2007 to 2014. The counterstrategies for Gwangyang port to address this situation include establishing cooperative relations and continuing the win/win relationships with cooperative ports.