• Journal of agriculture & life science
• /
• v.50 no.5
• /
• pp.111-120
• /
• 2016

The objective of this study was to provide basic information for selecting the right timing and the right place of erosion control of stream on Gyeongsangnam-do. In order to achieve this objective, a total of 526 erosion control dams and 230 mountains stream conservation facilities on the constructed places and construction planned places for the erosion control were investigated on site, forest physiognomy, and hydrologic conditions. The erosion control dams and mountain stream conservation facilities were mostly constructed in the area, which has the sedimentary rock, 200-400m of altitude, a slope of 21~30°, and II of landslide hazard map. Among the forest environmental factors, it was only similar to the construction frequency in the areas that have small diameter class, III age class. Also, we investigated the hydrological environmental factors that determine the size and numbers of erosion control dam. The places constructed to the highest frequency were below 50ha in the area, 2.1~4.0km/㎢ of drainage density, longitudinal water system, 61~90mm of maximum precipitation per hour, and 201~300mm of day maximum precipitation. As the results, the sites and floodgate conditions between the constructed places and stream conservation facilities for the erosion control showed to be very similar. Therefore, these results indicate that the erosion control of the stream of the areas, which have the disruption of mountain peaks and the high erosion risk areas, should be used on both the erosion control dam and stream conservation facilities.

• Journal of the Korea Institute of Building Construction
• /
• v.22 no.1
• /
• pp.69-80
• /
• 2022

The proportion of buildings over 30 years old in Korea has increased, from 29.0% in 2005 to 37.8% in 2019. These old buildings were built during a time in which there was a lack of building-related safety standards in areas such as fire safety performance. Worse, during their years of use, many such old buildings have had illegal changes and extensions made, making them more vulnerable in terms of safety. Fire safety investigations are being conducted to prevent large-scale disasters in multi-use buildings, but no investigation has been conducted at the regional district level, where small-scale old buildings are concentrated. Therefore, to identify fire risk factors in the old building district where old buildings are concentrated, the composition characteristics of the buildings were first analyzed. To examine the spatial characteristics of old building districts in order to derive fire risk factors, the results of this analysis based on the structure, use, roof type, and year of approval for use are as follows. It was found through our analysis that as of the date of approval for the use of the building, the main structure of the building has the greatest impact.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.50 no.4
• /
• pp.259-267
• /
• 2022

The existing method of deriving the fail-safe design requirements for the domestic developed rotary-wing aircraft system may miss the factors that cause critical system function failures, when being applied to the latest integrated avionics system. It is because the existing method analyzes the severity effect of the failures caused by a single item. To solve the issue, we present a systematic analysis procedure for deriving fail-safe design requirements of system architecture by utilizing functional hazard assessment and development assurance level analysis of SAE ARP4754A, international standard for complex system development. To demonstrate that our proposed procedure can be a solution for the aforementioned issue, we set up experimental environments that include common factors that can cause critical function failures of a system, and we conducted a cross-validation with the existing method. As a result, we showed that the proposed procedure can identify the potential critical common factors that the existing method have missed, and that the proposed procedure can derive fail-safe design requirements to control the common factors.

• Tuberculosis and Respiratory Diseases
• /
• v.78 no.4
• /
• pp.341-348
• /
• 2015

Background: There have been various results from studies concerning the predictors of recurrence in early-stage nonsmall cell lung cancer (NSCLC). Therefore, an accurate assessment is needed to guide effective adjuvant therapy. We investigated the predictors of a recurrence in patients with resected, early-stage NSCLC and the risk factors associated with locoregional or distant recurrence. Methods: This retrospective study was conducted on patients at the Pusan National University Hospital from January 2006 to December 2011. Patients with pathological stages I or II were included in this study, as based on the seventh edition TNM staging system. Multivariate Cox proportional hazard models were used to identify factors associated with recurrence. Results: Two hundred and forty-nine patients were included. Among them, 180 patients were stage I, and 69 were stage II. Overall, by multivariate analysis, the independent factors associated with a 5-year total recurrence were the presence of visceral pleural invasion (VPI) (p=0.018) and maximal standardized uptake values (SUVs) of tumors on positron emission tomography (PET) >4.5 (p=0.037). The VPI was the only independent risk factor associated with both locoregional and distant recurrence, in the analysis of the patterns of tumor recurrence and their risk factors. In the subgroup analysis of stage I patients, three variables (male, VPI and resection margin positive) were significantly associated with a 5-year recurrence. Conclusion: The independent factors associated with postoperative recurrence in early-stage NSCLC were as follows: PET SUV >4.5 and the presence of VPI. For patients with those factors adjuvant therapy should be recommended as a more efficacious treatment.

• Journal of Yeungnam Medical Science
• /
• v.35 no.2
• /
• pp.171-178
• /
• 2018

Background: To evaluate mid-term oncological and functional outcomes in patients with prostate cancer treated by robot-assisted laparoscopic radical prostatectomy (RALP) at our institution. Methods: We retrospectively reviewed the medical records of 128 patients with prostate cancer who underwent RALP at our institution between February 2008 and April 2010. All patients enrolled in this study were followed up for at least 5 years. We analyzed biochemical recurrence (BCR)-free survival using a Kaplan-Meier survival curve analysis and predictive factors for BCR using multivariate Cox regression analysis. Continence recovery rate, defined as no use of urinary pads, was also evaluated. Results: Based on the D'Amico risk classification, there were 30 low-risk patients (23.4%), 47 intermediaterisk patients (38.8%), and 51 high-risk patients (39.8%), preoperatively. Based on pathological findings, 50.0% of patients (64/128) showed non-organ confined disease (${\geq}T3a$) and 26.6% (34/128) had high grade disease (Gleason score ${\geq}8$). During a median follow-up period of 71 months (range, 66-78 months), the frequency of BCR was 33.6% (43/128) and the median BCR-free survival was 65.9 (0.4-88.0) months. Multivariate Cox regression analysis revealed that high grade disease (Gleason score ${\geq}8$) was an independent predictor for BCR (hazard ratio=4.180, 95% confidence interval=1.02-17.12, p=0.047). In addition, a majority of patients remained continent following the RALP procedure, without the need for additional intervention for post-prostatectomy incontinence. Conclusion: Our study demonstrated acceptable outcomes following an initial RALP procedure, despite 50% of the patients investigated demonstrating high-risk features associated with non-organ confined disease.

• Economic and Environmental Geology
• /
• v.54 no.1
• /
• pp.91-103
• /
• 2021

In order to estimate the vertical and horizontal structural in the Yangsan fault core line (Naengsuri area, Pohang), we carried out gravity field measurements and interpretation procedures such as Euler deconvolution method and curvature analysis in addition to the forward modelling technique (i.e. IGMAS+). We found a prominent gravity difference of more than 1.5 mGal across the fault core. This indicates a distinct density difference between the western and eastern crustal area across the Yangsan fault line. Comparing this gravity field interpretation with other existent geologic and geophysical survey data (e.g. LiDAR, trenching, electric resistivity measurements), It is concluded that (1) the prominent gravity difference is caused by the density difference of about 0.1 g/㎤ between the Bulguksa Granite in the west and the Cretaceous Sandstone in the east side, (2) the fault core is elongated vertically into a depth of about 2,000 meters and extended horizontally 3,000 meters to the NNE direction from Naengsuri area. Our results present that the gravity field method is a very effective tool to estimate a three -dimensional image of the active fault core.

• Journal of Energy Engineering
• /
• v.25 no.1
• /
• pp.23-28
• /
• 2016

In spite of various merit of algae as biofuel, the production cost of algae is a considerable obstacle for commercialization. The concurrent development of essential technologies is needed for the cultivating, harvesting, extracting and energy transformation. The production cost of algae biofuel has still higher than that of the other commercial biofuel. The major research activity has been focused on the cultivating and the research of other processes has been done with relatively lower activity. It is difficult to separate the algae from water because of the similar magnitude of density each other. The agglomeration and extracting of algae with the hybrid technology using ultrasonic wave is rare effect of environmental hazard and also it is appropriate technology for the next generation energy resources. The present research is investigated for the effective separation of algae from water with the ultrasonics wave. The aim of the present research is focused on the establishment of optimal design of algae agglomeration system. For this purpose, the computational fluid dynamic analysis has been conducted in the flow field with ultrasonic wave and algae flow to clarify the mechanism of algae separation by ultrasonic wave.

• Journal of Sasang Constitutional Medicine
• /
• v.22 no.2
• /
• pp.93-100
• /
• 2010

1. Objectives: To compare the contents of hazardous substances such as crude, washing solution, crude after washing, decoction and remnant. 2. Methods: The heavy metal contents of each step were measured by inductively coupled plasma (ICP) spectrometer and mercury analyzer (MA-2). In order to analyze pesticides in Yanggyeoksanhwa-tang we used simultaneous multi- residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide (SO2) were performed by Monier-Williams distillation method. 3. Results: 1) The mean values of heavy metal contents (mg/kg) for each steps in Yanggeoksanhwa-tang were as follows: crude (Pb; 1.87, As; 1.29, Cd; 0.28 and Hg; N.D.), washing solution (Pb; 1.98, As; 1.13, Cd; 0.10 and Hg; N.D.), crude after washing (Pb; 1.90, As; 1.40, Cd; 0.22 and Hg; N.D.), decoction (Pb; 1.90, As; 1.14, Cd; 0.11 and Hg; N.D.) and remnant (Pb; 2.39, As; 1.29, Cd; 0.25 and Hg; 0.01). 2) Contents (mg/kg) of residual pesticides in crude and decoction were not detected. 3) Contents (mg/kg) of sulfur dioxide (SO2) in crude, crude after washing and remnant exhibited 3.00, 2.00 and 2.00 mg/kg, respectively. However, contents of sulfur dioxide in washing solution and decoction were not detected. 4. Conclusions: These Results: will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide of each step in Yanggeoksanhwa-tang.

• Journal of Energy Engineering
• /
• v.26 no.4
• /
• pp.67-73
• /
• 2017

For the bio-fuel conversion of algae, several processes are needed including cultivating, agglomeration, extracting and conversion to the bio-fuel. The production cost for each process makes the total production cost of algae bio-fuel conversion. The production cost of algae bio-fuel has still higher than that of the other commercial bio-fuel. The reduction of production cost for each process enables the competitive price as a bio-fuel. It is difficult to separate the algae from water because of the similar magnitude of density each other. The agglomeration and extracting of algae using ultrasonic wave is rare effect of environmental hazard and also it is appropriate technology for the next generation energy resources. The present research is investigated for the elucidation of algae behavior in the water with the ultrasonics wave. For this purpose, the unsteady computational fluid dynamic analysis has been conducted in the ultrasonic pressure field. The velocity, pressure and algae concentration changes with time have been analysed to clarify the mechanism of algae separation by ultrasonic wave.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.5D
• /
• pp.445-451
• /
• 2012

Visual changes and speed changes in curved sections of highways are more dangerous than straight sections According to the enquetes conducted by Coalition for Transportation Culture in 1999, about 78% of drivers are dissatisfied with traffic guide and safety signs, with lack of visibility being the largest reason with about 27.9% of respondents indicating it as reason for dissatisfaction. In particular, the lack of visibility during nighttime or bad weather not only threatens driver safety due to poor delivery of information, but also affects the service level of highways. Because of this a new delineation must be installed and managed to enhance driver visibility. In this research, an optimal delineation system to enhance traffic safety is presented. In this research drivers effectively obtained information on highway alignment on the curved sections using a retro-reflection type delineation system and a newly-developed internal lighting delineation system to improve safety on the highways. A statistical comparison was conducted and analysis was done for the delineation systems that enhanced visibility through primary and secondary enquaetes. As a result, inside-lighting delineator will be selected in terms of safety at the curve sections. The inside-lighting delineator was more effective than the retro-reflection delineator on visibility, the necessity of reduction of speed and will reduce the hazard at curve sections. It is anticipated that when a delineation system based on this research is installed, a reduction in the number the number and severity of traffic accidents on curved sections will be reduced. In addition this system will more effectively provide drivers with information about highway alignment.