• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.192-203
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• 2020

Although the market demand for cold-chain logistics of agricultural products in China is growing rapidly, the technology and scale of cold-chain logistics in China still lag behind the developed countries, resulting in large energy consumption. In our country, many authors have studied the efficiency of cold-chain logistics by using analytic hierarchy process and data envelopment method, but they haven't eliminated the influence of environmental factors and random error factors on the efficiency of cold-chain logistics, and most of them are limited to regional research. Therefore, in this paper, the three-stage DEA method is used. Based on the green logistics idea, firstly, the efficiency of 29 listed logistics enterprises in China is analyzed. Secondly, this paper uses SFA model to exclude the influence of environment and error factors on the analysis results, taking the enterprise's operating years, local GDP and the proportion of cold chain assets as environmental variables. Finally, this paper estimates the efficiency value again by adjusting the input value. The results are as follows: the main reason of high efficiency enterprises is to achieve scale efficiency. So the scale of assets should be maintained or appropriately expanded. At the same time, the economic development and the number of years of enterprise establishment will significantly affect the efficiency of cold-chain logistics. The influence of these environmental variables on the accuracy of the analysis conclusion should be fully considered.

• Journal of the Korean Data and Information Science Society
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• v.23 no.2
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• pp.247-256
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• 2012

Recently, estimation of greenhouse gas (GHG) emission has continuously emerged as an important global issue. This study compares various statistical methods for estimation of fuel consumption, which is necessary for calculation of GHG emission in road transportation sector. Existing methods have focused on using merely transportation fuel supply or distance traveled for calculation of fuel consumption. Estimates of GHG emission based on fuel supply, however, cannot reflect various vehicle types or model year. This study suggests and compares, from statistical point of view, several methods, which can be applied to estimate fuel consumption of each vehicle, by combining distance traveled and fuel efficiency (mileage), and total fuel consumption of all vehicles. It also suggests practical measures that can reflect vehicle types and model year to suggested methods for future research.

• Korean Journal of Community Nutrition
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• v.8 no.2
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• pp.202-219
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• 2003

The present study was conducted to evaluate the food and nutrients intakes of stomach cancer patients in the Daegu and Gyeongbuk areas in order to find out the dietary risk factors for stomach cancer. The subjects of the study were 102 patients who had recently been diagnosed with stomach cancer at the Gyeongbuk National University Hospital. The control subjects were 105 people including patients from the Department of Orthopedic Surgery and healthy volunteers who did not have any gastrointestinal diseases. Estimates of nutrients intakes were determined from the food intake frequency data obtained by individual interviews using questionnaires. The mean daily calorie intakes of the control and the case groups were not significantly different. However the energy intake from protein was significantly higher in the case group as compared to the control group. With regard to the nutrients intakes, the case subjects consumed significantly higher amounts of nutrients such as protein, calcium, sodium, phosphorus and niacin than the control group. The case group showed a tendency to consume higher amount of protein, fat, calcium and iron from animal food sources. In the present study dietary factors which were suspected as being risk factors for stomach cancer included high consumption of animal foods, specific nutrients such as protein, sodium and niacin, specific food groups such as meat, spices, and low consumption of fruits and mushrooms. Therefore, it is recommended that more extensive and systematic surveys be conducted to confirm the risk factors for stomach cancer, taking into consideration the dietary cultural characteristics of this region. (Korean J Community Nutrition 8(2) : 202∼219, 2003).

• Smart Structures and Systems
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• v.16 no.1
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• pp.163-181
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• 2015

This research investigates the structural health monitoring of nonlinear structures after a major seismic event. It considers the identification of flag-shaped or pinched hysteresis behavior in response to structures as a more general case of a normal hysteresis curve without pinching. The method is based on the overall least squares methods and the log likelihood ratio test. In particular, the structural response is divided into different loading and unloading sub-half cycles. The overall least squares analysis is first implemented to obtain the minimum residual mean square estimates of structural parameters for each sub-half cycle with the number of segments assumed. The log likelihood ratio test is used to assess the likelihood of these nonlinear segments being true representations in the presence of noise and model error. The resulting regression coefficients for identified segmented regression models are finally used to obtain stiffness, yielding deformation and energy dissipation parameters. The performance of the method is illustrated using a single degree of freedom system and a suite of 20 earthquake records. RMS noise of 5%, 10%, 15% and 20% is added to the response data to assess the robustness of the identification routine. The proposed method is computationally efficient and accurate in identifying the damage parameters within 10% average of the known values even with 20% added noise. The method requires no user input and could thus be automated and performed in real-time for each sub-half cycle, with results available effectively immediately after an event as well as during an event, if required.

• The Korean Journal of Applied Statistics
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• v.33 no.6
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• pp.739-751
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• 2020

Seoul public bike program facilitates access to bicycles and offers potential for greater mobility and health for users. Furthermore, it would have positive impacts on transport congestion, energy use, and the environment. Hence, it is important to find future rental locations by taking to account both bike-demand and regional imbalance. This paper first finds eligible candidates of rental locations with the required spatial conditions such as a sufficient sidewalk width and accessibility of bike pick-up vehicles. And then, estimates public bike daily usage for each selected location via random forest based on Seoul public bike historical usage, Seoul geographical features, regional characteristics, and populations. This study contributes to a better comprehension of the Seoul public bike program, and would be useful in determining new public bike rental locations.

• Environmental and Resource Economics Review
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• v.29 no.4
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• pp.443-468
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• 2020

Broad effects of fuel-transition in all type of ground transportation have occurred with the help of the advances in electric vehicle (EV) technologies and the increases in EV supply. This research estimates the economic benefit of air environmental improvements, which results from the fuel-transition of high-mileage business cars(taxies) in metropolis. If we consider power production sector for EV operation, some air pollutants will be produced. In this respect, this research takes both the mixture of power sources in power production level and the driving pattern of business cars into account when investigating the economic benefit in air environment resulted from the fuel-transition of business cars(taxies). According to our results, the business cars' fuel transition from LPG to electricity brings about 21.5￦/km (8.6million won/year) of economic benefit in air environment. These results emphasize the necessity and appropriateness of public polices for expanding power production with renewable energies and facilitating EV distribution.

• Wind and Structures
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• v.34 no.5
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• pp.395-405
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• 2022

Tornado-induced damages to high-rise buildings and low-rise buildings are quite different in nature. Tornado losses to high-rise buildings are generally associated with building envelope failures while tornado-induced damages to low-rise buildings are usually associated with structural or large component failures such as complete collapses, or roofs being torn off. While studies of tornado-induced structural damages tend to focus mainly on low-rise residential buildings, transmission towers, or nuclear power plants, the current rapid expansion of city centers and development of large-scale building complexes increases the risk of tornadoes impacting tall buildings. It is, therefore, important to determine how tornado-induced load affects tall buildings compared with those based on synoptic boundary layer winds. The present study applies an experimentally simulated tornado wind field to the Commonwealth Advisory Aeronautical Research Council (CAARC) building and estimates and compares its pressure coefficient effects against the Atmospheric Boundary Layer (ABL) flow field. Simulations are performed at the Wind Engineering, Energy and Environment (WindEEE) Dome which is capable of generating both ABL and tornadic winds. A model of the CAARC building at a scale of 1:200 for both ABL and tornado flows was built and equipped with pressure taps. Mean and peak surface pressures for TLV flow are reported and compared with the ABL induced wind for different time-averaging. By following a compatible definition of the pressure coefficients for TLV and ABL fields, the resulting TLV pressure field presents a similar trend to the ABL case. Also, the results show that, for the high-rise building model, the mean and 3-sec peak pressures are larger for the ABL case compared to the TLV case. These results provide a way forward for the code implementation of tornado-induced pressures on high-rise buildings.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.17 no.2
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• pp.63-72
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• 2022

Objectives This case study aimed to investigate the effect of complex Korean medicine treatment including Chuna manual therapy on sacroiliac joint (SIJ) pain status post SIJ fusion with sacroiliac screw fixation. Methods Complex Korean medicine treatments including Chuna manual therapy were provided to patients with SIJ widening due to a traffic accident trauma. Measurement of range of motion and manual muscle test to evaluate functional activities of daily living was conducted before and after treatment. Moreover, outcome estimates were performed using the numeric rating scale, pain disability index, and EuroQol 5-dimension five-level questionnaire. Results After complex treatment, functional activities of daily living improved. Sacroiliac joint pain decreased and the quality-of-life score improved. Conclusions This study suggests that treatment with complex Korean medicine treatment including Chuna manual therapy may improve traumatic SIJ widening status post SIJ fusion. A postoperative rehabilitation protocol based on accumulated research results considering a multidisciplinary approach should be prepared to ensure holistic treatment.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.1949-1958
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• 2023

The International Commission on Radiological Protection (ICRP) Publication 116 was released to provide a comprehensive dataset of the dose coefficients (DCs) for external exposures produced with the adult reference voxel phantoms of ICRP Publication 110. Although an advanced skeletal dosimetry method for photons and neutrons using fluence-to-dose response functions (DRFs) was introduced in ICRP Publication 116, the ICRP-116 skeletal DCs were calculated by using the simple method conventionally used (i.e., doses to red bone marrow and endosteum approximated by doses to spongiosa and/or medullary cavities). In the present study, the photon and neutron DRFs were used to produce skeletal DCs of the ICRP-110 reference phantoms, which were then compared with the ICRP-116 DCs. For photons, there were significant differences by up to ~2.8 times especially at energies <0.3 MeV. For neutrons, the differences were generally small over the entire energy region (mostly <20%). The general impact of the DRF-based skeletal DCs on the effective dose calculations was negligibly small, supporting the validity of the ICRP-116 effective DCs despite their skeletal DCs derived from the simple method. Meanwhile, we believe that the DRF-based skeletal DCs could be beneficial in better estimates of skeletal doses of individuals for risk assessments.

• Environmental and Resource Economics Review
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• v.33 no.1
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• pp.87-112
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• 2024

This study estimates the regional input-output table and GHG emissions in 2019 and then analyzes the economic effects of carbon taxes by region and industry in Korea. The GHG emission, emission coefficient, and emission induction coefficient are estimated to be higher in manufacturing-oriented metropolitan provinces. The GHG emission coefficient in the same industry varies from region to region, which might reflect the standard of product classification, characteristics of production technology, and the regional differences in input structure. If a carbon tax is imposed, production costs are expected to increase and demand and production will decrease, especially in the manufacturing industry, which emits more GFG. On the other hand, the impact of carbon taxes on each region is not expected to vary significantly from region to region, which might be due to the fact that those differences are mitigated by industry-related effects. Since the impact of carbon taxes is expected to spread to the entire region, close cooperation between local governments is necessary in the process of implementing carbon neutrality in the future.