• Journal of Korean Society of Water and Wastewater
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• v.11 no.3
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• pp.51-58
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• 1997

Determining sizes and the locations of reservoirs in the water distribution system(WDS) with multi-reservoirs is much difficult than that with single reservoir. The extended period simulation(EPS) models provide more comprehensive analysis of water distribution systems than the steady-state models can do. Therefore, EPS models should be applied to the WDS with multi-reservoirs. This study is to investigate the variations of required reservoir sizes and residual nodal pressures according to reservoir locations. In this study, EPS was applied to analyze an artificial and a real WDS under several water demand patterns. As a result, it was found that water demand patterns make no significant differences in the determining of the reservoir size, if they have similar peaking factors. And the variations of the peaking factor should be carefully checked in the design and the analysis of the WDS with multi-reservoirs, because the peaking factor itself will affect the minimum allowable sizes of reservoirs in those systems.

• Journal of Chest Surgery
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• v.50 no.5
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• pp.329-338
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• 2017

Background: The clinical value of 3-field lymph node dissection (3FLND) in esophageal squamous cell carcinoma (ESCC) remains controversial. This study aimed to identify the patterns and prognostic significance of cervical lymph node metastasis (CLNM) in ESCC. Methods: A retrospective review of 77 patients with E SCC who underwent esophagectomy and 3FLND between 2002 and 2016 was conducted. For each cervical node level, the efficacy index (EI), overall survival, recurrence rate, and complication rate were compared. Results: CLNM was identified in 34 patients (44.2%) who underwent 3FLND. Patients with CLNM had a significantly lower overall survival rate (22.7% vs. 58.2%) and a higher recurrence rate (45.9% vs. 16.3%) than patients without CLNM. CLNM was an independent predictor of recurrence in ESCC patients. Moreover, in patients with pathologic N3 tumors, the odds ratio of CLNM was 10.8 (95% confidence interval, 2.0 to 57.5; p=0.005). Level IV dissection had the highest EI, and level IV metastasis was significantly correlated with overall survival (p=0.012) and recurrence (p=0.001). Conclusion: CLNM was a significant prognostic factor for ESCC patients and was more common among patients with advanced nodal stages. Level IV exhibited the highest risk of metastasis, and dissection at level IV may be crucial when performing 3FLND, especially in advanced nodal stage disease.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2439-2443
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• 2016

Purpose: To determine the risk factors, clinical symptoms and patterns of spread in laryngeal cancer. Materials and Methods: A cross sectional study was carried out in the Regional Cancer Centre, Imphal, Manipur, India. One hundred and sixteen patients with laryngeal cancer were retrospectively reviewed for epidemiological data and descriptive statistics were reported for various variables. Results: Median age at presentation was 65 years and 32.8% were undernourished at presentation. The male to female ratio was 5.4:1. Heavy smoking and tobacco chewing was associated in 91.4% and 33.6% of patients respectively. Tracheostomy was required in 21.5% leading to diagnosis of laryngeal cancer. Almost all were squamous cell carcinoma with neuroendocrine and verrucous carcinoma accounting for less than 2%. Supraglottic, glottic and trans-glottic tumors were 56.9%, 36.3% and 6.9% respectively. Nodal metastases were seen in 81.8% of supraglottic cancers and 31.6% of glottic cancers with supraglottic involvement. Level II neck nodes were the commonest site followed by level III. Distant metastases (only liver) were apparent in 1.7% at presentation. Including these liver metastases, unresectable cases were limited to 6% of the patients. Conclusions: Tobacco use is implicated in almost all of the cases and the sex ratio has also decreased due to increased female smokers. The supraglottis remains the commonest site and incidence of nodal metastases is higher than in other countries. There is also a higher requirement for tracheostomy at presentation in this region.

• 한국해양학회지
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• v.28 no.2
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• pp.86-100
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• 1993

Three-dimensional baroclinic hydrodynamic model, BACHOM-3, is developed using ADI finite difference scheme. The model is applied to a uni-nodal standing wave in a rectagular basin. The model results for the surface elevation and velocities coincide with the analytical results. To verify the field applicability of the model and to investigate the flow patterns of the Suyoung Bay in Pusan, Korea, the model is applied to the bay. The numerically predicted velocity predicted velocity fields during spring tide at normal river flow are compared with field measurements, the comparisons show good agreement. A clockwise residual circulations at the first level (depth = 0∼2m) and the second level (depth=2∼5 m) of the central part of the bay occur, and the ebb flow is stronger than the flood flow. Computed velocity fields show that the phase difference of velocities between the surface layer and bottom layer occurs and the phase lag increases with height from the bottom. Then, the model is applied successfully for the computation of flow fields considering flood river flow and wind effects. When the wind is blowing toward the land from the sea, the flow patterns at the surface layer correspond with the wind direction, but the flow patterns at the near solid boundary of the lower layer show opposite currents to the wind direction.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.11
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• pp.1426-1433
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• 1999

Topological and kinematical studies of the singular points found in flows around a surface-mounted cube in a channel are presented. Numerical simulation was carried out using high-resolution grid systems. Singular points(saddles and nodes) were found around the cube, which satisfy the topological rules suggested by Hunt et al. As the Reynolds number increases, the structure of vortices around the cube becomes complex and the number of singular points increases. Nevertheless, the rule governing the numbers of singular points is still valid. This confirms that our simulation is correct from topological and kinematical point of view, and enables one to infer complex flow patterns in our simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.486-490
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• 1997

Composite materials have varios complicated characteristics to the ply materials, ply orientations, ply stacking sequences and boundary conditions. Therefore, it is difficult to analysis composite materials. For efficient use of composite materials in engineering applications the dynamic behavior, that is, natural frequencies, nodal patterns should be informed. This study presents the experimental and FEM results for the free vibration of symmetrically and antisymmetrically laminated composite and hybrid composite rectangular plates. In order to demonstrate the validity of the experiment, FEM analysis using ANSYS was performed and natural frequencies experimentally obtined is compared with that calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2513-2519
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• 2000

Free vibration characteristics of an initially stressed CD/DVD disk, which is designed for increasing critical speeds of current optical disks, are analyzed using the Rayleigh-Ritz technique based on variational formulations. Natural frequencies of the new disk depend on membrane stresses caused by disk rotation as well as residual stresses imposed during the cooling process of the injection molding. Critical speeds are calculated for the various initial patterns of radial and circumferential stresses. Initially imposed tensile stresses increase the natural frequencies of all the vibration modes except zero nodal diameter mode, whose natural frequency is independent of circumferential stress. A new disk with initial tensile stress of 0.5MPa is shown to have its critical speed about 30 % higher than the current optical disk.

• Journal of the Korean Society of Safety
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• v.12 no.2
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• pp.37-44
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• 1997

Composite materials have various complicated characteristics depending on the ply materials, ply orientations, ply stacking sequences and boundary conditions. Therefore, it is difficult to analyze composite materials. For efficient use of composite materials in engineering applications, the dynamic behavior such as natural frequencies and nodal patterns should be identified. This study presents FEM results for the free vibration of symmetrically and antisymmetrically laminated composite and hybrid composite rectangular plates. The natural frequencies of laminated composite rectangular plates having the various boundary conditions (completely clamped, 2-edge clamped, cantilevered) are experimentally obtained. In order to demonstrate the validity of the experiment, FEM analysis using ANSYS was performed and natural frequencies experimentally obtained is compared with that calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.

• Radiation Oncology Journal
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• v.33 no.2
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• pp.83-88
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• 2015

Purpose: To evaluate the appropriateness of prophylactic inguinal nodal irradiation (PINI), we analyzed patterns of failure in anal cancer patients who were inguinal node-negative at presentation and did not receive PINI. Materials and Methods: We retrospectively reviewed the records of 33 anal cancer patients treated by definitive concurrent chemoradiation therapy (CCRT) between 1994 and 2013. Radiotherapy consisted of a total dose of 44-45 Gy (22-25 fractions in 5 weeks) on the whole pelvis, anus, and perineum. Except inguinal lymphadenopathy was present at initial diagnosis, the entire inguinal chain was not included in the radiation field. In other words, there was no PINI. Results: The median follow-up duration was 50 months (range, 4 to 218 months). Median survival and progression-free survival (PFS) were 57 months (range, 10 to 218 months) and 50 months (range, 4 to 218 months), respectively. Among the survival, the median follow-up duration was 51 months (range, 12 to 218 months). The 5-year overall survival and PFS rates were 93.4% and 88.8%, respectively. Although none of the patients received inguinal node irradiation for prophylactic purposes, there was no inguinal recurrence. Conclusion: Treatment of anal cancer by omitting PINI might be considered in selected patients with clinically uninvolved inguinal nodes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5B
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• pp.321-329
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• 2012

Two regular progressive wave trains, the directions of which are slightly different from each other, develop a honeycomb pattern of wave crests due to their nonlinear interaction. In the honeycomb pattern of wave crest, the nodal line area, which has very low wave energy, is formed. When the honeycomb pattern is developed near the beach area, rip current evolves through the nodal line area formed in the cross shore direction. In this study, to confirm that the formation of honeycomb pattern of waves near the beach area is a dominant mechanism of rip current occurred at Haeundae beach, we performed a numerical simulation of nearshore circulation at Haeundae beach under an unidirectional and monochromatic wave condition by using a nonlinear Boussinesq equation model. As a result, wave refraction due to topographical characteristics (i.e., submerged shoal) of Haeundae gave rise to several wave trains propagating with slightly different directions toward the beach, and consequently rip currents well developed through the nodal line area of honeycomb patterns of wave crest. In addition, we found that a narrow-banded spectral wave condition (i.e., a swell spectrum) increases more likelihood of rip current than a broad-banded spectral wave condtion based on the simulations employing various wave spectra with an equivalent wave height and period.