• Membrane Journal
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• v.19 no.1
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• pp.25-33
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• 2009

PES (polyethersulfone) membranes with highly enhanced their asymmetry were prepared by phase inversion process. The membranes were prepared by using PES/DMF (N,N-dimethylformamide)/TSA (p-toluenesulfonic acid)/PVP (polyvinylpyrrolidone) casting solution and water coagulant. The pre-coagulation of membrane surface which was induced by an addition of TSA as a demixing agent and PVP as a swelling polymer in the PES solution and humid exposure time, played a crucial role in determining morphological properties and the PWP (pure water permeation) performance. The PES solution was coated on polyester film under condition of 80% humidity for a while ($72{\sim}144$ sec) before immersing in a coagulation bath. The characterization of membranes was carried out by a capillary flow porometer, a FE-SEM and a permeation test apparatus. As the thickness of the smallest pore size layer (SPL) decreased, the asymmetry of membrane increased under conditions of 20 wt% of TSA and 10 wt% of PVP in 11 wt% of PES solution during longer humid contact time. As a result, the membranes showed a remarkable increase of PWP.

• Journal of Korean Neurosurgical Society
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• v.58 no.3
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• pp.225-230
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• 2015

Objective : The clinical outcomes according to the radiological results after cervical total disc replacement (TDR) are not well established. Here, the authors reviewed the clinical results according to the asymmetry in radiographs. Methods : This retrospective analysis included patients after TDR ($Mobi-C^{(R)}$ disc) with at least 12 months follow up, and the clinical and radiological data were obtained preoperatively and postoperatively for 12 months. Clinical outcome measures numerical rating scale (NRS) score for neck pain, visual analog scale (VAS) for arm pain, and the Oswestry disability index (ODI) value. The asymmetries of TDRs were evaluated on the anterior-posterior (AP) and the lateral radiographs, and the radiographic adjacent segment degenerations were evaluated for 12 months. Results : A total of 24 patients (one level cervical TDR; 10 male and 14 female; aged $41.50{\pm}8.35years$) were included in this study. The clinical results including NRS for neck pain, VAS for arm pain, and ODIs were similar between the normal and asymmetrized TDRs in AP and lateral radiographs. The radiographic adjacent segment degenerations were significantly increased in deviated TDRs (AP >10 mm asymmetry and lateral>10 mm asymmetry). Conclusion : Asymmetrical location of TDR is not related to the clinical outcomes, but related to the risk of radiographic adjacent disc segment degeneration.

• Journal of IKEEE
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• v.1 no.1 s.1
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• pp.11-18
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• 1997

By utilizing the technique to monitor the DC cell node voltages through circuit simulation, degradation of the static read operating margin In high load-resistor SRAM cell was examined, which is caused by parasitic resistances and transistor asymmetries in this cell structure. By selectively adding the parasitic resistances to an ideal cell, the influence of each parasitic resistance on the operating margin was examined, and then the cases with parasitic resistances in pairs were also examined. By selectively changing the channel width of cell transistors to generate cell asymmetry, the influence of cell asymmetry on the operating margin was also examined. Analyses on the operating margins were performed by comparing the supply voltage values at which two cell node voltages merge to a single value and the differences of cell node voltages at VDD=5V in the simulated node voltage characteristics. By determining the parasitic resistances and the transistor asymmetries which give the most serious effect on the static read-operation of SRAM cell from this analysis based on circuit simulated, a criteria was provided, which can be referred in the design of new SRAM cell structures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.448-456
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• 2011

Introduction: Condylar fractures are common in the maxillofacial region, comprising 29-40 percent of all mandibular fractures, accounting for about 20-62 percent). Previous studies reported that pediatric condylar fractures can cause disorders in facial growth and function, and the treatment methods have been controversial. Recently, conservative treatment has shown good results in skeletal growth and functional recovery but the conservative treatment of pediatric condylar fractures has shown unpredictable and undesirable results in some cases, such as facial asymmetry and temporomandibular joint disorder. This study examined the specific age groups and specific mandibular condylar fracture type in growing children treated conservatively in the past. Materials and Methods: Eighteen patients (10 men and 8 women) who received conservative treatment for unilateral condylar fractures in Dankook University Dental Hospital between 2000 to 2007 were followed up for a mean period of 7.2 years. Results: In the survey of 18 pediatric patients who received conservative treatment for condylar fractures, the incidence of temporomandibular dysfunction and growth disturbance was 45% and 35%, respectively. Conclusion: In all complications, the symptoms observed most frequently was mouth opening displacement of the mandible exceeding 2 mm. The other complications of functional and growth disturbance included facial asymmetry concentrated along specific condylar types. Complications including facial asymmetry and functional and growth disturbances showed an increasing tendency according to the specific fracture types. Functional and growth disturbances in the undisplaced condylar fracture type showed a lower incidence(P <0.05). Functional and growth disturbances differed according to the fracture type, which has poor relationship with articular fossa and condyle(P <0.05). Functional and growth disturbance in the cases of the high-level condylar fracture type showed a higher incidence(P <0.05). The functional and growth disturbances of the fracture types were similar in the fragment-contact and non-contact groups(P >0.05).

• The Korean Journal of Quaternary Research
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• v.5 no.1
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• pp.33-45
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• 1991

Sand bars associated with strong tidal currents are well developed in the subtidal zone near the Kokunsan islands. Tidal currents measured at sand bar in the area show an asymmetry in magnitude between flood and ebb currents. At the southern flank of the sand bar the currents are flood-dominant whereas the currents are ebb-dominant at the northern flank. The asymmetry is more distinctive as the currents become stronger during spring tide. Moreover, the flood-dominance along the southern flank is stronger than the ebb-dominance along the northern flank. Thus the flood current is more affective to the sand bar. The sandy bottom sediment is mostly transported as bedload by the tidal currents. The magnitude asymmetry of the tidal currents results in a net sediment movement in one direction. The direction is onshore in the south and offshore in the north, which may result in a net counterlookwise rotation of the sands around the sand bar. However, the sand bar may migrate towards onshore due to the more affective flood current in the south. The irregular V-shaped outline of the sand bar in the south also seem to reflect the strong effect of flood current.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.297-308
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• 2020

This study exemines the roles of corporate social activity (CSR) and executive compensation structure on the pricing of seasoned equity offerings (SEOs) with special focus on the role of CSR in reducing the level of information asymmetry between managers and future shareholders of issuing firms through SEOs. This study also investigates the interaction between executive compensation structure and CSR on the discounting of SEOs. We use a sample of 2,102 seasoned equity offerings of U.S. firms with CSR scores from 1995 to 2015 in our OLS fixed effect regression analysis. The results show that issuing firms with high CSR are more likely to expericence a lower degree of the SEO discount. The results also document a positive association between CSR and a high proportion of equity-based compensation of issuing firms' executives. The findings of this paper confirm that CSR attenuates the impact of information asymmetry and the pre-SEO price uncertainty on the pricing of the offers and hence the SEO discount. Furthermore, CSR reinforces the impact of executive firm-related wealth on the discounting of seasoned equity offerings. It appears that firm-related wealth motivates managers to actively engage in reducing information asymmetry activities before SEOs, thereby decreasing the SEO discount.

• The Journal of Fisheries Business Administration
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• v.45 no.2
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• pp.29-38
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• 2014

This study is to analyse the timing of the structural change of price volatility and the asymmetry of price volatility during the period before and after the timing of the structural change of price volatility using Jeju Farming Olive Flounder's production area market price data from January 1, 2007 to June 30, 2013. The analysis methods of Quandt-Andrews break point test and Threshold GARCH model are employed. The empirical results of this study are summarized as follows: First, the result of Quandt-Andrews break point test shows that a single structural change in price volatility occurred on May 4, 2010 over the sample period. Second, during the period before structural change, daily price change rate has averagely positive value which means price increase, but during the period after structural change daily price change rate has averagely negative value which means price decrease. Also, daily volatility of price change rate during the period before structural change is higher than during the period after structural change. This indicates that price volatility decreases after structural change. Third, the estimation results of Threshold GARCH Model show that the volatility response against price increase is larger during the period after structural change than during the period before structural change. Also the result shows the volatility response against price decrease is larger during the period after structural change than during the period before structural change. And, irrespective of the timing of structural change, price increase has an larger effect on volatility than price decrease. This means volatility is asymmetric at price increase.

• Advanced Composite Materials
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• v.18 no.3
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• pp.265-285
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• 2009

Off-axis compressive deformation behavior of a unidirectional CFRP laminate at high temperature and its strain-rate dependence in a quasi-static range are examined for various fiber orientations. By comparing the off-axis compressive and tensile behaviors at an equal strain rate, the effect of different loading modes on the flow stress level, rate-dependence and nonlinearity of the off-axis inelastic deformation is elucidated. The experimental results indicate that the compressive flow stress levels for relatively larger off-axis angles of $30^{\circ}$, $45^{\circ}$ and $90^{\circ}$ are about 50 percent larger than in tension for the same fiber orientations, respectively. The nonlinear deformations under off-axis tensile and compressive loading conditions exhibit significant strain-rate dependence. Similar features are observed in the fiber-orientation dependence of the off-axis flow stress levels under tension and compression and in the off-axis flow stress differential in tension and compression, regardless of the strain rate. A phenomenological theory of viscoplasticity is then developed which can describe the tension-compression asymmetry as well as the rate dependence, nonlinearity and fiber orientation dependence of the off-axis tensile and compressive behaviors of unidirectional composites in a unified manner. It is demonstrated by comparing with experimental results that the proposed viscoplastic constitutive model can be applied with reasonable accuracy to predict the different, nonlinear and rate-dependent behaviors of the unidirectional composite under off-axis tensile and compressive loading conditions.

• Journal of the Ergonomics Society of Korea
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• v.32 no.3
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• pp.229-236
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• 2013

Objective: The purpose of this study was to analyze the effects of wearing spandex underwear on the muscle activity and heart rate during flexion and extension of trunk and knee joint. Background: Back pain continues to be the leading overall cause of physical illness and lowering productivity in workplace. Recently, the utility of assistive garment or back belt have been discussed to lessen the back pain as well as to preserve the right posture. Method: Ten males and ten females participated in the experiment. Gender, wearing spandex underwear and postures were used for independent variables, and muscle activity, the level of asymmetry of muscle activity and variation of heart rate were used as dependent variables. Muscle activity and heart rate were measured during flexion and extension of trunk and knee joint. Results: When wearing spandex underwear, the muscle activity was relatively low compared to the condition not wearing the spandex underwear. The symmetry of muscle activity and the variation of heart rate were statistically significant at the 0.05 significance level. In particular, it was found that the symmetry of muscle activity increased while wearing spandex underwear. Conclusion: Spandex underwear has an effect that can reduce asymmetry of right and left muscles which are relevant to leg because spandex underwear equally supports right and left low-back muscles. Application: The spandex underwear used in this study can apply to the rehabilitation as an useful assistive device.

• Management & Information Systems Review
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• v.35 no.4
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• pp.213-227
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• 2016

This study examines the effects of managerial ability on information asymmetry. We use analyst forecast errors as a proxy for information asymmetry, because analysts are referred to as efficient users using firm-level data. The sample consists of 2,246 non-banking firm-years listed in Korea Stock Exchange(KOSPI) during the period 2000 to 2013. We measure managerial ability using DEA(Data Envelopment Analysis) following Demerjian et al.(2012). Using those measures, we examines the effects of managerial ability on analysts' earnings forecast errors and analysts' earnings forecast bias. The results of this study are as follows. First, we find that managerial ability are positively associated with analysts' earnings forecast accuracy. Second, we show that the firms with higher managerial ability tend to have lower the optimistic errors in analysts' earnings forecasts. This study could be useful for outside stakeholders to understand the importance of managerial ability.