• Environmental and Resource Economics Review
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• v.22 no.4
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• pp.643-670
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• 2013

This study analyzed the impact of crude oil inventory while gasoline price adjusts to international crude oil price(WTI) fluctuations. We mainly focused on asymmetric relationship between crude oil and petroleum product prices and added oil inventory as an variable, using the error correction model which is based on Borenstein et al.(1997). This paper selected the sample period from January 1988 to December 2012, analyzed the asymmetry of each intervals and the influence of crude oil inventory to the degree of asymmetry changes, both full period and five years period respectively. The results showed that when considering crude oil inventory, existence and degrees of time amount asymmetry varies.

• Environmental and Resource Economics Review
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• v.22 no.4
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• pp.613-641
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• 2013

This paper uses the error correction model to analyse dynamic gasoline price adjustments of the four refiners. Unlike the existing studies, this model allows a refiner's asymmetric adjustment to changes in the other refiners' prices as well as in its own price and costs. With the estimation results, we can obtain the following findings. First, there are the asymmetric price adjustments to changes in exchange rate and international gasoline price, but showing opposing directions. Second, for most of the refiners, the prices respond immediately to the lagged deviation from the long run equilibrium price, but asymmetrically respond for a few refiners. Third, there are some refiners that adjust their price to the other refiners' price deviation from the long run equilibrium. For some refiners, there are competitive price adjustments to the others' price deviations. These findings imply that a refiner faces inelastic demand, intends to maintain implicitly a relative level of its own price to others, and tends to respond competitively to the others' price deviation from the equilibrium.

• Journal of KIISE:Information Networking
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• v.34 no.6
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• pp.466-474
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• 2007

Asymmetric networks that the downlink bandwidth is larger than the uplink bandwidth may cause the degradation of the TCP performance due to the uplink congestion. In order to solve this problem, this paper designs and implements the Dynamic Segment Size Control mechanism which offers a suitable segment size for current networks. The proposed mechanism does not require any changes in customer premises but suppress the number of ACKs using segment reassembly technique to avoid the uplink congestion. The gateway which adapted the Dynamic Segment Size Control mechanism, detects the uplink congestion condition and dynamically measures the bandwidth asymmetric ratio and the packet loss ratio. The gateway reassembles some of segments received from the server into a large segment and transmits it to the client. This reduces the number of corresponding ACKs. In this mechanism, the SACK option is used when occurs the bit error during the transmission. Based on the simulation in the GEO satellite network environment, we analyzed the performance of the Dynamic Segment Size Control mechanism.

• Food Science of Animal Resources
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• v.44 no.1
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• pp.74-86
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• 2024

Eggs that have been hard-boiled are frequently used as ready-to-eat food. Refrigerated and frozen storage of hard-boiled eggs causes issues, such as customer rejection owing to textural changes. The objective of this research is to ascertain how storage temperature affects hard-boiled eggs' alteration in texture over time. Medium-sized brown shell eggs were acquired from a local market, boiled at 100℃ for 15 min, and then stored at room temperature (25℃), refrigeration (4℃), and freezing (-18℃) conditions for 0, 12, 24, and 48 h. Fourier transform infrared spectroscopy (FTIR), texture profile, visual observation using a gemological microscope, free amino acid content, and color were measured. Freezing had a substantial impact on the eggs' hardness, gumminess, chewiness, and cohesiveness (p<0.05). The FTIR spectrums confirmed the textural changes in bonds of amide A (3,271 cm^-1), amide I (1,626.2 cm^-1), amide II (1,539.0 cm^-1), C=O stretch of COO^- (1,397 cm^-1), asymmetric PO₂^- stretch (1,240 cm^-1). Microscopic images confirmed structural changes in eggs stored at -18℃. The free amino acid content was lower in fresh and frozen eggs than in the rest (p<0.05). However, there was no discernible variation in the egg white's color when eggs were kept at 4℃ (p>0.05). Salmonella spp. was found exclusively in eggs kept at room temperature. In conclusion, hard-boiled eggs did not exhibit structural or chemical changes when stored at 4℃ for up to 48 h compared to freezing and room temperature conditions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.5
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• pp.373-381
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• 2021

Objectives: In the present study, the effects of sagittal split ramus osteotomy (SSRO) combined with intraoral vertical ramus osteotomy (IVRO) for the treatment of asymmetric mandible in class III malocclusion patients were assessed and the postoperative stability of the mandibular condyle and the symptoms of temporomandibular joint disorder (TMD) evaluated. Materials and Methods: A total of 82 patients who underwent orthognathic surgery for the treatment of facial asymmetry or mandibular asymmetry at the Department of Oral and Maxillofacial Surgery, Dong-A University Hospital, from 2016 to 2021 were selected. The patients that underwent SSRO with IVRO were assigned to Group I (n=8) and patients that received bilateral SSRO (BSSRO) to Group II (n=10, simple random sampling). Preoperative and postoperative three-dimensional computed tomography (CT) axial images obtained for each group were superimposed. The condylar position changes and degree of rotation on the superimposed images were measured, and the changes in condyle based on the amount of chin movement for each surgical method were statistically analyzed. Results: Group I showed a greater amount of postoperative chin movement. For the amount of mediolateral condylar displacement on the deviated side, Groups I and II showed an average lateral displacement of 0.07 mm and 1.62 mm, respectively, and statistically significantly correlated with the amount of chin movement (P=0.004). Most of the TMD symptoms in Group I patients who underwent SSRO with IVRO showed improvement. Conclusion: When a large amount of mandibular rotation is required to match the menton to the midline of the face, IVRO on the deviated side is considered a technique to prevent condylar torque. In the present study, worsening of TMD symptoms did not occur after orthognathic surgery in any of the 18 patients.

• Textile Coloration and Finishing
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• v.25 no.4
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• pp.241-246
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• 2013

The color properties of a white or nearly colorless fabric are represented by whiteness index (WI) or yellowness index (YI). These two indexes relate to a white fabric's color quality. The purpose of this study was to identify the properties of WI and YI on the CIELAB through the simulations of estimation data for a systemization of color quality control. The results indicated that the relationship between WI and YI was a negative correlation, however the coefficients of correlation function between WI and YI were depended on hue. There were two hue transition points of the rate of changes in WI and YI. These hue transition points were the reference points to divide the hue contribution to WI and YI. These points were not the point of h=0 and h=180 and asymmetric. In addition, where the colors were same distance from the white point on the CIELAB, the rate of changes in WI and YI by ${\Delta}$Ew were depending on hue. Specifically, when WI decreased, YI of reddish and yellowish tinted colors decreased more than bluish tinted colors.

• Transactions of Materials Processing
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• v.29 no.2
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• pp.69-75
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• 2020

The plastic strain ratio is one of the factors that affect the deep drawability of metal sheets. The plastic strain ratio of fully annealed Cu sheet is low, due to its texture being {001}<100>. In this study, in order to increase the plastic strain ratio of Cu sheets we investigated the effect of two treatments: 1^st the sheet was asymmetrically rolled and annealed, and 2^nd the sheet was symmetrically and asymmetrically rolled and subsequently annealed. The average plastic strain ratio (R_m) of the initial Cu sheet was 0.95 and |Δr| was 1.27. After the 2^nd treatment of 5.3% symmetric rolling and annealing of Cu sheet at 1000℃ for 60 min in Ar gas condition, the R_m was 2.29 times higher and the |Δr| was 1.44 times higher than that of initial Cu sheet specimen. After the 2^nd treatment of 8.2% asymmetric rolling and annealing of Cu sheet at 1000℃ for 60 min in Ar gas conditions, the R_m was 2.51 times higher and |Δr| was 0.53 times lower than that of the initial Cu sheet specimen. These results can be attributed to the change in texture of the Cu sheets due to the differences in the two methods of rolling.

• Convergence Security Journal
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• v.19 no.4
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• pp.55-66
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• 2019

For the past 66 years, the Korea-U.S. alliance has been a typical asymmetric alliance in which the U.S. supports South Korea's security during the Cold War and South Korea gives some of its policy autonomy to the U.S. But Lee Myung-bak government military alliance the 'comprehensive strategic alliance' of the character, 'value of alliance', Park Geun-hye ' a global, 'Frontier of cooperation', the government.'reciprocal, comprehensive alliance' Moon Jae-in, the government and partnerships developed with ' euroui the development of national security strategy said. The purpose of this study is to explore ways to build a reciprocal and comprehensive Korea-U.S. alliance for the development of the Korea-U.S. alliance policy in order to ensure South Korea's policy autonomy following changes in the Trump administration's alliance policy. The results of the research show the need for Korea to participate in the U.S.-led 'India-Pacific Strategy' continue diplomatic efforts for the mutual economic benefits of the two countries and strengthen public diplomacy in order to build the Korea-U.S. alliance in a reciprocal and comprehensive manner.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.259-266
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• 2020

This study analyzes the effects of the obsolescence assets on the asymmetry of costs. Cost asymmetry refers to a lower percentage of costs when sales fall than increases in costs when sales increase. the obsolescence asset induces various decisions, including high maintenance costs and management improvements and replacement of facilities. This study is to analyze the cost behavior according to those decisions. The analysis showed that the higher the obsolescence of assets rate, we found cost elasticity, with a greater reduction in costs when sales decrease than the increase in costs when sales increase. Second, the lower the cost will not appear as the obsolescence of assets rate increases in case that the concentration of an item of property, plant and equipment is high, and when sales decrease. The above result means that the obsolescence of assets rate acts as operating risk and thus operates resources flexibly according to changes in sales, but when the concentration of property, plant and equipment is high, the decision-making constraint make it difficult for the flexible operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.5
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• pp.342-349
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• 2013

A damage imposed on an unmanned aerial vehicle changes the flight dynamic characteristics, and makes difficult for a conventional controller based on undamaged dynamics to stabilize the vehicle with damage. This paper presents a neural network based adaptive control method that guarantees stable control performance for an unmanned aerial vehicle even with damage on the main wing. Additionally, Pseudo Control Hedging (PCH) is combined to prevent control performance degradation by actuator characteristics. Asymmetric dynamic equations for an aircraft are chosen to describe motions of a vehicle with damage. Aerodynamic data from wind tunnel test for an undamaged model and a damaged model are used for numerical validation of the proposed control method. The numerical simulation has shown that the proposed control method has robust control performance in the presence of wing damage.