• Journal of the Korean GEO-environmental Society
• /
• v.15 no.7
• /
• pp.5-11
• /
• 2014

Both ultraviolet (UV) and ultrasound (US) systems are used in degrading of organic contaminants and they can thus be applicable simultaneously as an UV/US hybrid system in attempts further to increase the degradation efficiency. The pseudo-first order degradation rate constants with the UV, US and UV/US hybrid irradiation were 2.60, 10.34, and $14.81{\times}10^{-3}min^{-1}$, respectively. It was observed that the synergistic effect of UV/US hybrid system for degrading the bis (2-ethylhexyl) phthalate (DEHP). The highest rate of DEHP degradation was found during UV/US hybrid irradiation and the synergistic effect factor (SEF) was calculated to be 1.15 based on the pseudo-first order degradation rate constants. Results indicate that synergistic effect of UV/US hybrid system is closely correlated to the enhancement of sonochemical reactivity with the UV-US interaction of increasing the formation rate of OHby providing additional $H_2O_2$ production through the pyrolysis of water molecules during UV/US hybrid irradiation.

• Asian review of World Histories
• /
• v.2 no.1
• /
• pp.47-80
• /
• 2014

After the outbreak of the Korean War on June 25, 1950, the US included the Republic of China on Taiwan (Taiwan hereafter) in its Asia-Pacific containment line, and restored the military and economic aid to Taiwan for the sake of regional security. The US aid to the countries along the Asia-Pacific defense line was not only in the form of supplying munitions, but also linked these countries together in an economic dimension. Taiwan is one of the 120 countries which had accepted US aid and also successfully moved from "dependence" to "independently sustained growth." This article will firstly review the historical background of US aid to Taiwan and related institutional development; secondly, this article will illustrate how Taiwan used US aid, and which economic sector the US aid affected; thirdly, it will trace the impact of US aid on Taiwan's foreign trade, and finally, to make a conclusion.

• Clinics in Shoulder and Elbow
• /
• v.24 no.2
• /
• pp.55-65
• /
• 2021

Background: Although ultrasound-guided needle decompression (US-GND) can treat calcific tendinitis of the shoulder effectively, repeat procedures might be required for unresolved symptoms. We evaluated the overall clinical outcomes of US-GND with subacromial steroid injection and the final results and factors predisposing toward repeat procedures. Methods: Ninety-eight patients who underwent US-GND for calcific tendinitis of the supraspinatus/infraspinatus were analyzed between March 2017 and December 2018. The clinical outcomes (pain visual analog scale, functional visual analog scale [FVAS], and American Shoulder and Elbow Surgeons [ASES] score) and final subjective satisfaction were compared between groups A (single US-GND) and B (repeat US-GND). The factors predisposing toward repeated US-GNDs were analyzed. Results: We found that 59.3% (58/98) of patient ASES scores were ≥80, and 73.5% of patients (72/98) were satisfied with the outcome. Group B (n=14) demonstrated a significantly higher rate of dominant-arm involvement compared to group A (78.6% vs. 48.8%, p=0.046). However, initial calcification size, shape, number, density, subscapularis involvement, lavage, and procedure time did not differ significantly between the groups. Group B showed poorer final FVAS (7 [interquartile range, 6-8] vs. 8 [interquartile range, 7-9], p=0.036) and subjective satisfaction compared to group A (satisfied: 5 [35.7%] vs. 67 [79.8%], p<0.001]. Conclusions: US-GND with subacromial steroid injection is a viable treatment option for calcific tendinitis of the shoulder. Dominant-arm involvement was the only independent factor for repeated US-GND. Final outcome of repeated US-GND for unimproved patients was promising; however, these outcomes were poor compared to those of the patients who improved after the first procedure.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.29 no.4
• /
• pp.41-46
• /
• 2021

In order to investigate the degree of sewage sludge solubilizaion using ultrasonic(US) combined with calcium peroxide(CaO₂), VSS reduction rate, solubilization rate, SCOD/VSS ratio, SCOD increasing rate, LB-EPS(Loosely-Bound EPS) and TB-EPS(Tightly-bound EPS) were measured. US was compared as a control. Solubilization rate increased by 23.4% under US and increased by 50.7% under US/CaO₂(0.05 g CaO₂/g VSS). and also, at the same conditions, VSS reduction rate increased by 7.1% and 17.7%, respectively. SCOD increasing rate from 10 to 90 minutes was 0.0151 min^-1 under US/CaO₂(0.02 g CaO₂/g VSS). TB-EPS decreased by 36.4% under US and decreased by 59.0% under US/CaO₂(0.05 g CaO₂/g VSS). TB-EPS decreased during first 10 minutes and then decreased slowly until 90 minutes. There was no significant difference in TB-EPS decrease according to the dosage of calcium peroxide.

• Ocean policy research
• /
• v.33 no.2
• /
• pp.1-23
• /
• 2018

The import control provision of US MSA (Magnuson-Stevens Fishery Conservation and Management Act) IUU fishing is similar to that of MMPA (The Marine Mammal Protection Act of 1972 as Amended) which caused US-Tuna(1991) case. This paper examines whether MSA's import control provision can be found to be inconsistent with WTO agreement. There is no doubt that MSA violates the Article XI:1 of the GATT 1994. The only remaining issue is whether US IUU fishing product measure is justified by the Article XX(g) and its Chapeau. However, Article XX(g) provides for a limited and conditional exception from obligations under other provisions. This paper concludes that the US MSA measure can not be justified under Article XX.

• Journal of Distribution Science
• /
• v.15 no.12
• /
• pp.41-51
• /
• 2017

Purpose - This study proposes the impact of the US and Korean economic policy uncertainty on macroeconomy, and its effect on Korea. The economic policy uncertainty index of the US and Korea is used to represent the economic policy uncertainty on Korean economy. Research design, data, and methodology - In this paper, we collect the eight variables to find out the interrelationship among the US and Korean economic policy uncertainty index of the US and macroeconomic indicators during 1990 to 2016, and use Vector Error Correction Model. Result - The distribution industry stock index in Korea is influenced by the economic policy uncertainty index of the US rather than of Korea. All variables are related negatively to the economic policy uncertainty index of the US and Korea from Vector Error Correction Model. This study shows that the economic policy uncertainty index of the US and Korea has the dynamic relationships on the Korean economy. Conclusions - A higher economic policy uncertainty shows a greater economy recession of a country. Finally, the economic policy uncertainty of the Korea has an intensive impact on Korea economy. Particularly, the economic policy uncertainty of the US has a strong impact on distribution industry stock market in Korea.

• Journal of Soil and Groundwater Environment
• /
• v.26 no.4
• /
• pp.1-7
• /
• 2021

The removal of PCBs (Polychlorinated biphenyls) in aqueous phase was investigated in the ultraviolet (UV) process, ultrasonics (US) process and ultraviolet/ultrasonic (UV/US) process using PCB No.7 and Aroclor 1260. For PCB No.7 relatively high removal efficiency over 90% was obtained during 20 min in the UV process and UV/US process. On the other hand, lower removal efficiency of 50 - 70% was achieved for it consisted of individual congeners of PCBs containing 3~8 of chlorine atom. It was found that the dechlorination reaction (the photolytic cleavage of C-Cl bond) was considered as a main removal mechanism in the UV process while PCBs were removed by cavitation-induced radical reaction in the US process. No significant dechlorination occurred in the US process. Consequently, it was suggested that the UV process or UV/US process was applicable for the removal of PCBs in aqueous phase in terms of the removal efficiency and operation time. In addition, the application of saturating gas such as Ar and Air could be considered to control redox condition and enhance the severity of acoustic cavitation for the removal of PCBs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.3
• /
• pp.285-292
• /
• 2008

Purpose: The present study was performed to evaluate the effect of surface treatment of the cervical area of implant on bone regeneration in fresh extraction socket following implant installation. Materials and methods: The four minipigs, 18 months old and 30 kg weighted, were used. Four premolars of the left side of both the mandible and maxilla were extracted. ${\phi}$3.3 mm and 11.5 mm long US II plus implants (Osstem Implant co., Korea) with resorbable blasting media (RBM) treated surface and US II implants (Osstem Implant co., Korea) with machined surface at the top and RBM surface at lower portion were installed in the socket. Stability of the implant was measured with $Osstell^{TM}$ (Model 6 Resonance Frequency Analyser: Integration Diagnostics Ltd., Sweden). After 2 months of healing, the procedures and measurement of implant stability were repeated in the right side by same method of left side. At four months after first experiment, the animals were sacrificed after measurement of stability of all implants, and biopsies were obtained. Results: Well healed soft tissue and no mobility of the implants were observed in both groups. Histologically satisfactory osseointegration of implants was observed with RBM surface, and no foreign body reaction as well as inflammatory infiltration around implant were found. Furthermore, substantial bone formation and high degree of osseointegration were exhibited at the marginal defects around the cervical area of US II plus implants. However, healing of US II implants was characterized by the incomplete bone substitution and the presence of the connective tissue zone between the implant and newly formed bone. The distance between the implant platform (P) and the most coronal level of bone-to-implant contact (B) after 2 months of healing was $2.66{\pm}0.11$ mm at US II implants group and $1.80{\pm}0.13$mm at US II plus implant group. The P-B distance after 4 months of healing was $2.29{\pm}0.13$mm at US II implants group and $1.25{\pm}0.10$mm at US II plus implants group. The difference between both groups regarding the length of P-B distance was statistically significant(p<0.05). Concerning the resonance frequency analysis (RFA) value, the stability of US II plus implants group showed relatively higher RFA value than US II implants group. Conclusion: The current results suggest that implants with rough surface at the cervical area have an advantage in process of bone regeneration on defect around implant placed in a fresh extraction socket.

• Journal of the Korean Society of Food Culture
• /
• v.32 no.1
• /
• pp.1-9
• /
• 2017

The objective of this study was to explore the role of familiarity in cross-cultural product perception and perception changes according to food systems (hot sauce and spicy-chicken) in Korean and US consumers. Free choice profiling was conducted by Korean and US consumers on four spicy-chicken samples made using four hot sauce samples. Half of the hot sauce samples were selected to be more familiar to US consumers and vice versa to Korean consumers. A previous study that investigated cross-cultural perceptions of the same four hot sauce samples in US and Korean consumers was incorporated in this study. For distinct sample differences, US and Korean consumers perceived products similarly. However, for less obvious differences, flavor familiarity seemed to affect consumers' product perceptions. In addition, product perceptions changed more dramatically according to food systems for familiar samples in each country. The findings of this study show that consumers' product perception can be affected by flavor familiarities.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.56 no.1
• /
• pp.56-62
• /
• 2007

In this paper, design method for power tower hazard diagnosis/predition system based on UsN was proposed. The proposed method used multi-hybrid sensors to measure rotation, displacement, and inclination state of power tower, and made decision/prediction of hazard of power tower. System design was made with requirement analysis of monitoring for transmission power facility and use of MEMS and optic fiber sensors. For hazard decision, analysis of correlation was made using sensor output. LN based on IEC61850,international standard for digital substation, was also proposed. For transmission facility monitoring, digital substation and power tower were considered as parts of power facility networks.