• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.8
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• pp.771-781
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• 2000

The Karman boundary-layer, has been numerically investigated for the disturbance wave number, wave velocity, azimuth angle and radius (Reynolds number, Re). The disturbed flow over rotating disk can lead to transition at a much lower Re than that of the well-known Type 1 mode of instability. This early transition is due to the excitation of the Type II mode. Presented are the neutral stability results concerning these modes by solving new formulated vorticity equations with consideration of whole convective terms. When the present numerical results are compared with the previously known results, the value of critical Re corresponding to Type I is moved from Rec,! =285.3 to 270.2 and the value corresponding to Type II is from $Re_{c,2}$=69.4 to 36.9, respectively. Also, the corresponding wave number is moved from $k_1$ =0.378 to $k_1$ =0.389 for Type I; from $k_2$ =0.279 to $k_2$=0.385 for Type II. For Type II, the upper limit of wave number and azimuth angle is $k_U$=0.5872,$varepsilon_U=-18^{\circ}$ , while its lower limit is$k_L$ =0.05, $varepsilon_L=-27^{\circ}$ This implies that the disturbances will be relatively fast amplified at small Re and within narrow bands of wave number compared with the previous results.

• Journal of Arbitration Studies
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• v.23 no.4
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• pp.139-167
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• 2013

Mediation, which is part of ADR, is a method used to settle disputes amicably by employing a third party who is in a neutral position. Utilization and attention on meditation are increasing in place of litigation and arbitration owing to its effectiveness in terms of time, cost, and effectiveness in achieving an amicable settlement. As to Korea, mediation at the civil level was employed by the KCAB in July 2012 but its utilization was in ABC stage compared to mediation at the governmental and judicial levels. Based on this situation, this study reviewed the guideline and system of the KCAB through a comparison of the management system between the KCAB and AAA where mediation was in good use. This study further suggests solutions as to the development of an international commercial mediation system First, the KCAB rule is needed to create a mediation language, mediation place, mediator internationalization, and so on. Second, a system backup is necessary to ensure the enforceability and effectiveness of mediation. Third, a unified mediation law in Korea is desirable for the harmonization of mediations at civil, governmental, and judicial levels. The unified mediation law, if it is made, may lead to an international base where this requirement exists. Fourth, advertising the merits of mediation to the public is necessary. Fifth, securing specialized mediators and relevant training are essential. If the above requirements are implemented, Korea would advance in international commercial disputes.

• Speech Sciences
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• v.7 no.4
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• pp.93-105
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• 2000

The English schwa sound has special characteristics which are distinct from other vowels. It is non-phonemic and occurs only in an unstressed syllable. Compared with the English schwa, the Korean /e/ is a full vowel which has phonemic contrast. This paper had three aims. One was to see whether there is any relationship between English full vowels and their reduced vowel schwas. Second was to see whether there is any possible target in the English schwa sounds which are derived from different full vowels. The third was to compare the English non-phoneme vowel schwa and the Korean full vowel /e/ in terms of articulatory positions and duration. The study results showed that there is no relationship between each of the full vowels and its schwa. The schwa tended to converge into a possible target which was F1 456 and F2 1560. The Korean vowel /e/ seemed to have its distinct position speaker-individual which is different from the neutral tongue position. The evidence that the Korean /e/ is a back vowel was supported by the Seoul dialect speaker. In duration, the English schwa was much shorter than the full vowels, but there was no significant difference in length between the Korean /e/ and other Korean vowels.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.1
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• pp.95-102
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• 1996

The skewness of near-bottom velocity distribution caused by the nonlinear interaction of the second order waves proposed by Wells (1967) has been re-evaluated. The direction of cross-shore sediment transport was related to the sign of the third moment (skewness) of velocity distribution, and a new concept of neutral depth which can explain the recovery of beach equilibrium after a disturbance is suggested. The seasonal change of beach profile due to the change of wave condition (storm-swell profile) is interpreted in terms of nonlinear interaction of the waves rather than the conventional wave steepness. The beach is eroded (storm profile) when the nonlinear interaction of the waves is strong (storm wave), whereas the beach is accreted (swell profile) when the nonlinear interaction is weak (swell wave).

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.2
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• pp.266-273
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• 1999

The maximum work capacity at various shoulder angles was estimated in terms of joint moment through maximum voluntary contraction (MVC) measurement, and the result was compared to workload computed from 3-D static lifting model (3DSSPP) based upon national institute of safety and health (NIOSH) lifting guideline (1991). The electromyography (EMG) of anterior/posterior deltoid and trapezius muscle was also recorded to study the function of individual muscle during asymmetric shoulder lifting. Psychophysical workload was measured to observe the difference from MVC or biomechanical estimation. An apparatus was constructed for the study and twenty five trials including five flexion angles and five add/abduction angles were performed isometrically. Results indicated that MVC at 30 degree of flexion was the strongest whereas MVC at 120 degree was the weakest. In case of add/abduction, MVC decreased to 77 to 89 % during add/abduction compared to the MVC at neutral position. Regarding the normalized EMG value, a substantial increase was observed at 30 and 60 degree abduction. More importantly, the shoulder moment computed from maximum permissible limit (MPL) was greater than the moment at MVC condition during 30 degree adduction. Current result can be used as a reference information for a safe workplace design to prevent the shoulder from an excessive work load in industry.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.4
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• pp.376-382
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• 2014

This paper proposes the pulse width modulation (PWM) control strategy for low-speed operation in the three-level neutral-point-clamped (NPC) inverters based on the bootstrap gate drive circuit. As a purpose of the cost reduction, several papers have paid attention to the bootstrap circuit applied to the three-level NPC inverter. However, the bootstrap gate driver IC cannot generate the gate signal to the IGBT for low-speed operation, because the bootstrap capacitor voltage decreases under the threshold level. For low-speed operation, the dipolar and partial-dipolar modulations can be the effective solution. However, these modulations have drawbacks in terms of the switching loss and THD. Therefore, this paper proposes the PWM control strategy to operate the inverter at low-speed and to minimize the switching loss and harmonics. The experimental results are presented to verify the validity on the proposed method.

• Bulletin of the Korean Chemical Society
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• v.6 no.3
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• pp.145-148
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• 1985

The effect of anionic polyelectrolytes, poly(styrenesulfonate) (PSS) and poly(vinylsulfonate) (PVS), on the charge transfer complexing between indole derivatives and methyl viologen($MV^{++}$) cation was investigated. The results were compared with effect of NaCl and an anionic surfactant, sodium dodecylsulfate (SDS). Both PSS and PVS enhanced the complex formation of neutral species (indole and indole acetate at low pH), zwitter ionic tryptophan, and positively charged tryptamine and tryptophan at low pH with $MV^{++}$. This result was attributed to the contribution of hydrophobic interaction, in addition to electrostatic interaction. The enhancing effect of PSS was much higher than that of PVS reflecting the higher hydrophobicity of PSS. The interaction between indole acetate anion and $MV^{++}$ was greatly reduced by addition of PVS and PSS. The higher charge density of PVS was appeared as greater reducing effect indicating the importance of electrostatic force in this case. In all cases, the effect of polyelectrolytes showed maxima, and further addition of PVS and PSS decreased the effect. This behavior was explained in terms of distribution of indole derivatives and $MV^{++}$ in domain of polyanions. The complex formation constants and molar absorptivities of complexes were determined, and the values were compared with those in water and SDS solutions.

• Journal of Korean Critical Care Nursing
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• v.14 no.3
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• pp.37-49
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• 2021

Purpose : This study aims to identify nurses' attitudes toward patients hospitalized after attempting suicide and inform directions for research and interventions to establish a therapeutic environment. Methods : For integrative review, the five stages suggested by Whittemore and Knafl were followed. Articles and theses published before February 2021 were searched using eight databases and a manual search. The search terms were suicide, self-harm, emergency department (ED), intensive care unit (ICU), nurses, and attitudes. Results : Five studies met the inclusion criteria; three of them were descriptive studies, one was a qualitative study, and one a mixed-method study. In most studies (80%), the participants were ED nurses. ED/ICU nurses showed positive or neutral attitudes toward patients. All studies suggested that suicide-related education programs are needed to increase nurses' positive attitudes such patients. Conclusion : More research is required on ICU nurses' attitudes toward patients who have attempted suicide, and efforts to identify various aspects of such attitudes are necessary. In addition, suicide education programs and support from trained psychiatric personnel should be provided to establish a therapeutic environment.

• Journal of Arbitration Studies
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• v.31 no.2
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• pp.77-98
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• 2021

International commercial mediation of intellectual property rights fully meets the interests of the parties in such disputes in terms of their needs for neutral forum of dispute resolution, cost-effective settlement, objective opinion of relevant experts, internationally enforceable solution. In addition, as a procedural flexibility, respected self-determination of the parties, exploration of possible creative business solutions, maintenance of business relationship and confidentiality of mediation are major characteristics which can be competitively differentiated from the lawsuit or arbitration. The settlement agreement as a result of the WIPO mediation has an effect of contract while the settlement agreement as a result of most domestic ones has an effect of judicial reconciliation which can be domestically enforced. The latter is not subject to the application of the Singapore Convention on Mediation which establishes a harmonized legal framework for the right to invoke settlement agreements as well as for their enforcement. The WIPO international mediation system and its experience may be a good reference for Korea to take an initiative to establish a globally competitive international mediation system in the area of intellectual property rights.

• Environmental Engineering Research
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• v.24 no.3
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• pp.513-520
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• 2019

In this investigation, nano ZnO was sonochemically synthesized by a novel method using a methionine precursor. A narrow size distribution (41-50 nm) of nano ZnO was achieved that was immobilized on perlite and applied as a catalyst in catalytic ozonation. The catalyst was characterized by fourier transform infrared spectroscopy, BET surface area, and field emission scanning electron microscope. The ozonation of recalcitrant Remazol black 5 (RB5) di-azo dye solution by means of the synthesized catalyst was investigated in a bubble column slurry reactor. The influence of pH values (7, 9, 11), catalyst dosage (8, 12, 15, $20g\;L^{-1}$) and reaction time (10, 20, 30, 60 min) was investigated. Although the dye color was completely removed by single ozonation at a higher reaction time, the applied nanocatalyst improved the dye declorination kinetics. Also, the degradation of the hazardous aromatic fraction of the dye was enhanced five-times by catalytic ozonation at a low reaction time (10 min) and a neutral pH. The second-order kinetics was best fitted in terms of both RB5 color and its aromatic fraction removal. The total organic carbon analysis indicated a significant improvement in the mineralization of RB5 by catalytic ozonation using the nano-ZnO/perlite catalyst.