• Annals of Coloproctology
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• v.34 no.6
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• pp.292-298
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• 2018

Purpose: This study compared the perioperative clinical outcomes of reduced-port laparoscopic surgery (RPLS) with those of conventional multiport laparoscopic surgery (MPLS) for patients with sigmoid colon cancer and investigated the safety and feasibility of RPLS performed by 1 surgeon and 1 camera operator. Methods: From the beginning of 2010 until the end of 2014, 605 patients underwent a colectomy for sigmoid colon cancer. We compared the characteristics, postoperative outcomes, and pathologic results for the patients who underwent RPLS and for the patients who underwent MPLS. We also compared the clinical outcomes of single-incision laparoscopic surgery (SILS) and 3-port laparoscopic surgery. Results: Of the 115 patients in the RPLS group, 59 underwent SILS and 56 underwent 3-port laparoscopic surgery. The MPLS group included 490 patients. The RPLS group had shorter operating time ($137.4{\pm}43.2minutes$ vs. $155.5{\pm}47.9minutes$, P < 0.001) and shorter incision length ($5.3{\pm}2.2cm$ vs. $7.8{\pm}1.2cm$, P < 0.001) than the MPLS group. In analyses of SILS and 3-port laparoscopic surgery, the SILS group showed younger age, longer operating time, and shorter incision length than the 3-port surgery group and exhibited a more advanced T stage, more lymphatic invasion, and larger tumor size. Conclusion: RPLS performed by 1 surgeon and 1 camera operator appears to be a feasible and safe surgical option for the treatment of patients with sigmoid colon cancer, showing comparable clinical outcomes with shorter operation time and shorter incision length than MPLS. SILS can be applied to patients with favorable tumor characteristics.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.231-240
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• 1997

In the United States, a number of ocean outfalls discharge primary treated effluent into deep sea water and contribute for more efficient wastewater treatment. The long multiport diffuser connected by long pipe from a treatment plant discharge wastewater into deep water due to the steep slope of the sea bed. However, Plume discharged from the diffuser can have significant impacts on coastal communities and possibly immediate consequence on public health. Therefore, there have been growing interests about the dynamics of plume in the vicinity of the ocean outfalls. It is expected that the ocean outfall should be considered for more efficient and reliable wastewater treatments as soon as possible around coastal area in South Korea. A number of studies of plume ynamics have used various models to predict plume behavior. However, in many cases, the calculated values of plume behavior are in significantly poor agreement with realistic values. Therefore, in this study, it is recommended that improvements should be made in the application of the plume model to more simulate the actual discharge characteristics and ocean conditions. It should be noted that input parameters in plume models reflect realistic ocean conditions like waves as well as currents. In this study, as one of the new parameters, current and long wave-influenced plume rise and initial dilution have been taken into account by using simple linear wave theory under some specific assumptions for more reliable plume behavior description. Among the improved plume models approved by EPA (Environmental Protection Agency), the RSB(Roberts-Snyder-Baurngartner) and UM(Updated Merge) models were chosen for the calculation of plume behavior, and the variation calculated by both models on the basis of long period wave was compared in terms of plume rise and initial dilution.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6B
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• pp.641-649
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• 2006

The behavior of a three-dimensional pure rectangular water jet with aspect ratio of 10 was experimentally investigated based on the results of the mean velocity field obtained by PIV. The saddle back distribution was observed in the lateral distribution along the major axis. The theoretical centerline velocity equation derived from the point source concept using the spreading rate for the axisymmetric jet was in good agreement with the measured centerline velocity and gave the division of the potential core region, two-dimensional region, and axisymmetric region. The range of the two-dimensional region divided by the criterion of the theoretical centerline velocity decay for the aspect ratio of 10 was observed to be smaller than that of the transition region. The applicability of the two-dimensional model to the behavior of the rectangular jet with low aspect ratio or the wastewater discharged from a multiport diffuser in the deep water of real ocean may result in significant error in the transition and axisymmetric regions after the two-dimensional region. In the two-dimensional region, the Gaussian constant tended to be conserved, and the spreading rate slightly decreased at the end of the two-dimensional region. The normalized turbulent intensity along the centerline of the jet initially abruptly increased and showed relatively higher intensity for higher Reynolds number.