• ETRI Journal
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• v.32 no.2
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• pp.241-247
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• 2010

We propose and experimentally demonstrate a service-aware optical transport system. The proposed service-aware optical transport system makes a flow based on service type and priority of traffic. The generated flow is mapped to a corresponding sub-${\lambda}$ for transport over an optical network. Using sub-${\lambda}$ provided by the centralized control plane, we could effectively provide quality-of-service guaranteed Ethernet service and best-effort service simultaneously in a single link. The committed information rate (CIR) traffic and best-effort traffic are assigned to different sub-${\lambda}s$. The bandwidth of the CIR traffic is guaranteed without being affected by violation traffic because the bandwidth is managed per each sub-${\lambda}$. The failure detection time and restoration time from a link failure is measured to be about 60 ${\mu}s$ and 22 ms, respectively, in the ring network. The measured restoration time is much smaller than the 50 ms industry requirement for real-time services. The fast restoration time allows the proposed service-aware optical transport system to offer high availability and reliability which is a requirement for transport networks.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.95-98
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• 2003

To provide high-quality media streaming service over the best-effort Internet, an efficient streaming system with a network-adaptive transport is essential. By adopting FEC-based adaptive transport and by matching it to the priority of media packets, in this paper, an enhanced MPEG-4 streaming system is implemented. The implemented adaptive transport can complement the existing MPEG-4 streaming server with components such as elementary stream provider, sync layer and DMIF layer. Sync layer packets of each MPEG-4 elementary stream are prioritized and then selectively dropped at the sender to match the currently available bandwidth. Also, with the proposed adaptive transport module, the level of FEC protection is dynamically adjusted based on the underlying network condition. With preliminary verification over the emulated network testbed, it is shown that the proposed implementation can mitigate the impact of network fluctuation and thus improve the quality of streaming.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.2
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• pp.142-158
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• 2012

This paper investigates the physical and chemical characteristics of long-range transport (LRT) process of air pollutants by employing the MM5-CMAQ and its comparison with local emission dominant (LED) case over northeast Asia. We first classified high air pollution days into LRT and LED cases based on the synoptic meteorological variables of vorticity and geostrophic wind speed/direction at a geopotential level of over 850hPa. LRT cases are further categorized into three types of transport patterns (LRT-I-III) according to the air mass pathways from source regions. LRT-I-III are originated from northern, central, and southern China, respectively, identified by back trajectory analysis. Three LRT-I-III groups have different and unique locations of high pressure and transport pathways. The chemical characteristics showed that the simulated spatial distributions varied in terms of locations of maximum concentrations and the temporal variation of surface concentrations. The primary air pollutants such as $NO_x$, $PM_{10}$ and $SO_2$ of all of three LRT cases are well transported into Korea peninsula with different concentration levels. Of LRT cases, LRT-II has the greatest effect on air quality of Korea peninsula, followed by LRT-I and LRT-III. In comparison with LRT, the LED case shows relatively higher air pollution concentrations in general, but showed a variety of different air quality levels following the emission strength pattern. These widely varying patterns are impling the case dependent multi-directional approach for the development of indicators of long-range transport process over northeast Asia.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.269-277
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• 2020

Bao Loc City is the new tourism destination in Lam Dong province, Vietnam, where more and more tourists have been drawn to pay a visit. This study aims to test the correlative impact of tourism service quality factors on satisfaction of the tourists who have visited Bao Loc City. The key theory used in this study is SERVQUAL scale. The survey sample consists of 350 tourists who stayed overnight in Bao Loc City in the last quarter of 2019; 315 valid survey questionnaires could be used for the analysis. The research applied Cronbach's Alpha, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), structural equation modeling (SEM), and bootstrap test. The results show that the satisfaction of the tourists who have visited Bao Loc City has been affected statistically by three factors: (1) Responsiveness; (2) Reliability; and (3) Empathy, which were ranked by descending importance. Surprisingly, the research found that Tangibles and Assurance do not have an impact on tourists' satisfaction towards Bao Loc City. The research formulates some suggestions to the city policy-makers and the tourism businesses management in Bao Loc City in order to enhance tourists' satisfaction through improving the tourism service quality at Bao Loc City.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.4
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• pp.329-339
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• 1993

Due to the global-convection currents, transboundary transport of air pollutants is widely observed in many regions of the world. This study was carried out to investigate the pattern of long-range transport of air pollutants in North East Asia, especially the impact of air pollutants originated in China and Japan on the air quality in Korea. From the meteorological data at the 850 mb surface from May 1986 through April 1987 at 54 obsevation stations in the North East Asia region, the backward and forward trajectories were calculated using interpolation method. And the contributions of pollution sources in neighbor countries to the air quality in Korea were analyzed. It was concluded that air pollution in China had a great influence on the air quality in Korea throughout the year : it could be transported to Korea just within 2 or 3 days most of the time. The trajectory analysis showed that pollution sources in Beijing. Liaoning Province, and Shandong Province, the most heavily industrialized areas in China., were the most influential for the air quality in Korea except for summer season. Durnig summer season, the air pollution in Shanhai and Japan could have moer influence on Korea. Such transboundary transport of air pollutants necessitate international cowork and cooperation in the region of North East Asia.

• Animal Bioscience
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• v.37 no.4
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• pp.697-708
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• 2024

Objective: The objective of this study was to investigate the influence of dietary supplementation of Eucommia ulmoides leaf extract (ELE) on muscle metabolism and meat quality of pigs with and without pre-slaughter transportation. Methods: In a 43-day feeding experiment, a total of 160 pigs with an initial body weight 60.00±2.00 kg were randomly assigned into four groups in a completely randomized design with 10 replicates. Pigs in groups A and C were fed a basal diet and pigs in groups B and D were fed a basal diet supplemented with 0.5% ELE. Pigs were slaughtered with (group B and D) or without (group A and C) pre-slaughter transport. Muscle chemical composition, postmortem glycolysis, meat quality and muscle metabolome were analyzed. Results: Dietary ELE supplementation had no effect on the proximate composition of porcine muscle, but increased free phenylalanine, proline, citruline, norvaline, and the total free amino acids in muscle. In addition, dietary ELE increased decanoic acid and eicosapentaenoic acid, but decreased heptadecanoic acid, oleic acid, trans-oleic acid, and monounsaturated fatty acids in muscle. Meat quality measurement demonstrated that ELE improved meat water holding capacity and eliminated the negative effects of pre-slaughter transport on meat cooking yield and tenderness. Dietary ELE reduced muscle glycolytic potential, inhibited glycolysis and muscle pH decline in the postmortem conversion of muscle to meat and increased the activity of citrate synthase in muscle. Metabolomics analysis by liquid chromatographic tandem mass spectrometric showed that ELE enhanced muscle energy level, regulated AMP-activated protein kinase (AMPK) signaling, modulated glycogenolysis/glycolysis, and altered the metabolism of carbohydrate, fatty acids, ketone bodies, amino acids, purine, and pyrimidine. Conclusion: Dietary ELE improved meat quality and alleviated the negative effect of pre-slaughter transport on meat quality by enhancing muscle oxidative metabolism capacity and inhibiting glycolysis in postmortem muscle, which is probably involved its regulation of AMPK.

• Industrial Engineering and Management Systems
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• v.13 no.2
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• pp.221-230
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• 2014

With the progress and prosperity of commerce and industry, time and money increasingly form an equal partnership. Using air carriers to shorten the round-trip time has become an important choice for many people in the tourism process. Faced with increasing competition within the aviation service environment, airline evaluation criteria and the requirements of customers are gradually dominating the evaluation mechanism for air transport service quality. Over the past few years, attention on the transport quality of service has been primarily focused more on land-based transport, and less on the relevant evaluation criteria of airlines. Many studies have shown that quality of service will directly affect customer satisfaction, resulting in the fact that good quality aviation services have become increasingly important. Therefore, in practical industrial operations with limited resources, there is an urgent need to delve into the assessment guidelines that have an impact on customers when they choose an airline, which can be used as a basis for improving customer satisfaction. Through a literature review and a reliability and validity analysis, this study summarized 19 evaluation criteria, using the purposive sampling method and the decision laboratory method (DEMATEL). In addition, this study viewed the causal relationship between the evaluation criteria and the degree of association as a continuing project for airlines. This study selected appropriate empirical samples from two domestic airlines. The conclusions may provide recommendations for all airlines.

• Korean Journal of Materials Research
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• v.16 no.8
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• pp.479-484
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• 2006

Highly c-axis oriented poly-crystalline GaN with a dimension of $1{\sim}3\;{\mu}m$ was deposited on $c-Al_2O_3$ substrate by vapor transport epitaxy (VTE) method at the temperature range of $900{\sim}1150^{\circ}C$. XRD intensities from (00'2) plane of grown GaNs were increased with reaction conditions which indicate the improvement of the crystal quality. In the PL spectra measured at 10 K, the spectrum composed with the neutral-donor bound exciton-related emission at 3.47 eV, crystal defect-related emission band at 3.42 eV and with its phonon replicas. The fact that intensity of $I_2$ were increased and FWHM were decreased with growth conditions means that the quality of GaN crystals were improved. With this simple VTE technology, we confirm that the GaNs were simply deposited on sapphire substrate and crystal quality related to optical properties of GaN grown by VTE were relatively good. PL emission without deep level emission in spite of polycrystalline structure can be applicable to the fabrication of large area and low cost optical devices using poly-GaN grown by VTE.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.132-140
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• 2024

In the event of a severe accident in Sodium Cooled Fast Reactors (SFR), the sodium combustion aerosols along with fission product aerosols would migrate to the environment through leak paths of the Reactor Containment Building (RCB) concrete wall under positive pressure. Understanding the characteristics of sodium aerosol transport through concrete leak paths is important as it governs the environmental source term. In this context, experiments are conducted to study the influence of various parameters like pressure, initial mass concentration, leak path diameter, humidity etc., on the transport and deposition of sodium aerosols in straight leak paths of concrete. The leak paths in concrete specimens are prepared by casting and the diameter of the leak path is measured using thermography technique. Aerosol transport experiments are conducted to measure the transported and plugged aerosol mass in the leak paths and corresponding plugging times. The values of differential pressure, aerosol concentration and relative humidity taken for the study are in the ranges 10-15 kPa, 0.65-3.04 g/m³ and 30-90% respectively. These observations are numerically simulated using 1-Dimensional transport equation. The simulated values are compared with the experimental results and reasonable agreement among them is observed. From the safety assessment view of reactor, the approach presented here is conservative as it is with straight leak paths.

• Journal of Korea Port Economic Association
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• v.17 no.1
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• pp.3-26
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• 2001

Competitive and reliable maritime transport services benefit the economy as a whole, and are key efficiency factors for the production of both goods and services. Although maritime transport sector is very liberalized compared to many other service sectors, certain obstacles must be overcome before full liberalization of the maritime transport can be realized. Particularly, maritime transport services in Northeast Asia are regulated by a complicated and outdated system. To remove these barkers two approaches can be used: a regional trading arrangement approach and a multilateral approach via WTO. However, multilateral efforts are not likely to be successful in achieving any concrete progress towards maritime transport liberalization in the short- to medium-term in Northeast Asia. Consequently, it may be the best to take the following two progressive approaches and to make them work towards liberalization of the maritime transport market: a bilateral approach and a trilateral approach. A gradual process of liberalization would expand the market, help operators achieve economies of scale, promote the international division of labor and specialization, enhance the effective management of shipping services, and promote the long-term interests and welfare of the user by improving service quality and diversifying services. A liberalized and integrated maritime transport market in Northeast Asia should achieve both of these long-run policy objectives by benefiting both the transport service users and the transport service providers. In order to move the maritime transport liberalization programs as quickly as possible, it is desirable to establish a "Regional Maritime Transport Liberalization Committee." We suggest it to be a Tripartite (China, Japan and Korea) Committee initially, which can later expand its membership to include other Northeast Asian countries.