• Title/Summary/Keyword: Time-scale analysis

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Analysis of Rainfall-Runoff Characteristics in Gokgyochun Basin Using a Runoff Model (유출모형을 이용한 곡교천 유역의 강우-유출 특성 분석)

  • Hwan, Byungl-Ki;Cho, Yong-Soo;Yang, Seung-Bin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.2
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    • pp.404-411
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    • 2019
  • In this study, the HEC-HMS was applied to determine rainfall-runoff processes for the Gokgyuchun basin. Several sub-basins have large-scale reservoirs for agricultural needs and they store large amounts of initial runoff. Three infiltration methods were implemented to reflect the effect of initial loss by reservoirs: 'SCS-CN'(Scheme I), 'SCS-CN' with simple surface method(Scheme II), and 'Initial and Constant rate'(Scheme III). Modeling processes include incorporating three different methods for loss due to infiltration, Clark's UH model for transformation, exponential recession model for baseflow, and Muskingum model for channel routing. The parameters were calibrated using an optimization technique with trial and error method. Performance measures, such as NSE, RAR, and PBIAS, were adopted to aid in the calibration processes. The model performance for those methods was evaluated at Gangcheong station, which is the outlet of study site. Good accuracy in predicting runoff volume and peak flow, and peak time was obtained using the Scheme II and III, considering the initial loss, whereas Scheme I showed low reliability for storms. Scheme III did not show good matches between observed and simulated values for storms with multi peaks. Conclusively, Scheme II provided better results for both single and multi-peak storms. The results of this study can provide a useful tool for decision makers to determine master plans for regional flood control management.

Construction of Mine Geospatial Information by Total Station and 3D Laser Scanner (토털스테이션과 3D 레이저 스캐너에 의한 광산공간정보 구축)

  • Park, Joon-Kyu;Lee, Keun-Wang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.3
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    • pp.520-525
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    • 2019
  • Mines are an important infrastructure for securing resources, but safety problems can arise in the course of operation. Recently, the mining process is very complicated due to the large scale and mechanization. Therefore, it is necessary to construct accurate geospatial information on mine for systematic and safe mine operation. The geospatial information construction using the existing total station has a disadvantage that a lot of work time is required because the target must be collimated and measured. In this study, the data of the mines were acquired with the total station and the 3D laser scanner, and the mine spatial information was constructed by using the shape based registration method. By using the static scanner data of some area applying the reference point surveying result of the total station, it was possible to construct the accurate result on the wide area acquired by the mobile scanner effectively. Also, the accuracy of the constructed geospatial information was evaluated and the deviation of mean 0.083m was shown. Point cloud products constructed through the research can contribute to the efficiency improvement of mine management by enabling quantitative analysis such as visualization of mine shape, distance, area and slope, and automation of drawing creation for cross section shape.

A Analytical Study on Seismic Performance of Stainless Water Tank using Lead Rubber Bearing (납고무받침을 이용한 스테인리스 물탱크 내진성능에 관한 해석적 연구)

  • Kim, Hu-Seung;Oh, Ju;Jung, Hie-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.230-236
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    • 2018
  • Earthquakes over 5.0 on the Richter scale have recently occurred in Korea, which has led to interest in the seismic safety of structures. If a water storage facility is damaged by an earthquake, the water could leak, and the insufficient water would make fire suppression difficult. Therefore, a water storage facility should satisfy safety requirements for earthquakes. In this study, the seismic performance of a water tank was improved by installing a lead rubber bearing between the foundation and the tank. It designed the lead rubber bearing available to the existed concrete foundation. ANSYS was used for modeling to consider the interaction between the fluid and structure of the tank and the hydrostatic and hydrodynamic pressure using four seismic waves. In the case of hydrostatic pressure at 2.5 water level, full level, the same stress appeared irrespective of whether the seismic isolation was installed. When hydrostatic pressure and hydrodynamic pressures are applied at the same time, the seismic-isolated water tank showed less seismic force, and the damping ratio was lower than that of general seismic isolation. This occurred because the weight of the water tank is much smaller than the stiffness of the seismic isolation. The result is expected to be used for further research on seismic capacity evaluation for water tanks.

An Approach for the Antarctic Polar Front Detection and an Analysis for itsVariability (남극 극 전선 탐지를 위한 접근법과 변동성에 대한 연구)

  • Park, Jinku;Kim, Hyun-cheol;Hwang, Jihyun;Bae, Dukwon;Jo, Young-Heon
    • Korean Journal of Remote Sensing
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    • v.34 no.6_2
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    • pp.1179-1192
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    • 2018
  • In order to detect the Antarctic Polar Front (PF) among the main fronts in the Southern Ocean, this study is based on the combinations of satellite-based sea surface temperature (SST) and height (SSH) observations. For accurate PF detection, we classified the signals as front or non-front grids based on the Bayesian decision theory from daily SST and SSH datasets, and then spatio-temporal synthesis has been performed to remove primary noises and to supplement geographical connectivity of the front grids. In addition, sea ice and coastal masking were employed in order to remove the noise that still remains even after performing the processes and morphology operations. Finally, we selected only the southernmost grids, which can be considered as fronts and determined as the monthly PF by a linear smoothing spline optimization method. The mean positions of PF in this study are very similar to those of the PFs reported by the previous studies, and it is likely to be well represents PF formation along the bottom topography known as one of the major influences of the PF maintenance. The seasonal variation in the positions of PF is high in the Ross Sea sector (${\sim}180^{\circ}W$), and Australia sector ($120^{\circ}E-140^{\circ}E$), and these variations are quite similar to the previous studies. Therefore, it is expected that the detection approach for the PF position applied in this study and the final composite have a value that can be used in related research to be carried out on the long term time-scale.

The Development of XML Message for Status Tracking the Importing Agrifoods During Transport by UBL (UBL 기반 수입농수산물 운송 중 상태 모니터링을 위한 XML 메시지 개발)

  • Ahn, Kyeong Rim;Ryu, Heeyoung;Lee, Hochoon;Park, Chankwon
    • The Journal of Society for e-Business Studies
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    • v.23 no.3
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    • pp.159-171
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    • 2018
  • The imported foods, which are imported and sold domestically, are on the rise every year, and the scale is expected to be larger, including processing the imported raw materials. However, the origin of raw materials is indicated when declaring cargo for finished products of agricultural products, but the standardization of inspection information management system for raw materials is insufficient. In addition, there is a growing concern about the presence of residual pesticides or radioactivity in raw materials or products, and customer want to know production history information when purchasing agrifoods. It manages the hazard analysis of imported agricultural products, but most of them are global issues such as microorganisms, residual pesticides, food additives, and allergy components, etc. Therefore, it is necessary to share among the logistics entities in the entire transportation process the related data. Additionally, to do this, it needs to design an architecture and standardize business model. In this paper, it defines the architecture and the work-flow that occurs between the business process for collecting, processing, and processing information for tracking the status of imported agricultural products by steps, and develops XML message with UBL and the extracted conceptual information model. It will be easy to exchange and share information among the logistics entities through the defined standard model and it will be possible to establish visibility, reliability, safety, and freshness system for transportation of agricultural products requiring real-time management.

The Effectiveness and Safety of Acupuncture for Recovery of Patients with Vertebral Compression Fractures: A Systematic Review and Meta-analysis (척추 압박 골절 환자의 회복에 대한 침 치료의 유효성 및 안전성 평가: 체계적 문헌 고찰과 메타분석)

  • Bae, Ji min;Lee, Myeong su;Choi, Ji won;Yang, Gi young;Kim, Kun hyung
    • Korean Journal of Acupuncture
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    • v.36 no.1
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    • pp.1-18
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    • 2019
  • Objectives : The purpose of this study was to evaluate the effectiveness and safety of acupuncture treatment for recovery of patients with vertebral compression fracture(VCF). Methods : We searched ten English and Chinese and seven Korean database up to April 2018. Randomised controlled trials(RCTs), quasi-RCTs, non-radomised Controlled Trials(CCTs) were eligible. Quasi-RCTs and CCTs were assessed only for safety assessment. Pain and adverse events were primary outcome of this review. Quality of life, dysfunction, patient satisfaction, incidence of new vertebral compression fracture were regarded as secondary outcomes. The risk of bias was assessed by two independent authors using the Cochrane risk of bias tool. Level of evidence was tabulated using the GRADE methods. Results : Of 1656 screened, 15 RCTs, 1 quasi-RCT and 3 CCTs were included. Number of participants per study ranged from 45 to 135. Most of the studies had unclear or high risk of bias and considerable heterogeneity in terms of type of intervention, comparison and time-points for outcome measurement. Compared to usual care alone, acupuncture combined with usual care showed short-term favorable results for pain relief in patients with VCF(5 studies, n=252, MD -1.05 point on a 0 to 10 point scale, 95% CI -1.45 to -0.65, $I^2=74%$). Four studies reported mild and temporary adverse events, and no serious adverse events were reported. One study descriptively reported that acupuncture was effective for improving quality of life without providing numerical outcomes. There were no reports of patient satisfaction and incidence of new VCF. Conclusions : Level of evidence is very low for the effectiveness and safety of acupuncture for pain, harms and other clinical outcomes in patients with VCF. Included studies suffered from incomplete reporting, high or unclear risk of bias and substantial heterogeneity between studies. Future high-quality RCTs are needed to assess whether acupuncture is beneficial for recovery of patients with VCF.

The Role of Double Inversion Recovery Imaging in Acute Ischemic Stroke

  • Choi, Na Young;Park, Soonchan;Lee, Chung Min;Ryu, Chang-Woo;Jahng, Geon-Ho
    • Investigative Magnetic Resonance Imaging
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    • v.23 no.3
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    • pp.210-219
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    • 2019
  • Purpose: The purpose of this study was to investigate if double inversion recovery (DIR) imaging can have a role in the evaluation of brain ischemia, compared with diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) imaging. Materials and Methods: Sixty-seven patients within 48 hours of onset, underwent MRI scans with FLAIR, DWI with b-value of 0 (B0) and $1000s/mm^2$, and DIR sequences. Patients were categorized into four groups: within three hours, three to six hours, six to 24 hours, and 24 to 48 hours after onset. Lesion-to-normal ratio (LNR) value was calculated and compared among all sequences within each group, by the Friedman test and conducted among all groups, for each sequence by the Kruskal-Wallis test. In qualitative assessment, signal intensity changes of DIR, B0, and FLAIR based on similarity with DWI and image quality of each sequence, were graded on a 3-point scale, respectively. Scores for detectability of lesions were compared by the McNemar's test. Results: LNR values from DWI were higher than DIR, but not statistically significant in all groups (P > 0.05). LNR values of DIR were significantly higher than FLAIR within 24 hours of onset (P < 0.05). LNR values were significantly different between, before, and after six hours onset time for DIR (P = 0.016), B0 (P = 0.008), and FLAIR (P = 0.018) but not for DWI (P = 0.051). Qualitative analysis demonstrated that detectability of DIR was higher, compared to that of FLAIR within 4.5 hours and six hours of onset (P < 0.05). Also, the DWI quality score was lower than that of DIR, particularly relative to infratentorial lesions. Conclusion: DIR provides higher detectability of hyperacute brain ischemia than B0 and FLAIR, and does not suffer from susceptibility artifact, unlike DWI. So, DIR can be used to replace evaluation of the FLAIR-DWI mismatch.

A Study on the Risks Factors of Fire Occurrence and Expansion for Traditional Markets (전통시장 화재 발생 및 확대 위험요인에 관한 연구)

  • Kim, Jung-Gon;Park, Chang-Il;Jung, Jae-Wook;Kim, Seong-Gon
    • Journal of the Society of Disaster Information
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    • v.17 no.1
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    • pp.60-67
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    • 2021
  • Purpose: Traditional markets often have irregular space utilization patterns because the spaces are created and divided as time passed. Internally, there is high risk of fire due to problems such as aging facilities and high-density of stores and externally, there is high risk of fire spread since it is often adjacent to deteriorated residential and commercial facilities. Method: In this paper, on-site investigations were carried out to check fire risk factors and fire spread risk, and fire occurrence and expansion risk factors were investigated for traditional markets in Hwanghak-dong and Dong-daemun by using large-scale fire data from existing traditional markets. Result: As a result of the analysis, there are likely to be various problems such as high fire load and lack of safety awareness due to aging facilities and high-density of stores. In particular, it is necessary to prepare countermeasures because deteriorated residential facilities with narrow alleys around traditional markets have high fire spread. It is situation that while traditional markets mainly are managing for fire and disaster centering on the merchant association, the surrounding residential areas are not properly managed. Conclusion: It is necessary to manage deteriorated residential facilities with traditional markets, also to be linked early warning system and information to evacuate rapidly in case of fire there.

Monitoring Urban Ecological corridors in Gwanggyo New Town Using Camera Trapping (카메라트래핑을 활용한 광교신도시 내 도시형 생태통로 모니터링)

  • Park, Il-Su;Kim, Whee-Moon;Kim, Seoung-Yeal;Park, Chan;Song, Won-Kyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.24 no.1
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    • pp.69-80
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    • 2021
  • The new town in Korea, developed as a large-scale housing plan, has created urban ecological corridors to provide habitat and movement routes to wildlife and to promote natural ecological flow. This study aimed to investigate the use of wildlife in 10 ecological corridors in Gwanggyo New Town through camera trap technology and confirm effectiveness by identifying environmental factors affecting the use of wildlife's urban ecological corridors. Our researchers installed 20 unmanned sensor cameras at each the entrance and exit of the ecological corridors, and monitored urban wildlife for 10 weeks. According to the monioring results, the main species in Gwanggyo New Town were identified not only raccons, cats, water deer, korean hare and avain but also magpies, dove, eurasian tree sparrow, ring-necked pheasant, and eurasian jay. The number of uses ecological corridors of urban residents was 801(13.49%), as high as that of urban wildlife (1,140, 19.20%), which was judged to have disturbed the use of ecological corridors by wildlife. However, most dominant species of urban wildlife are nocturnal so that, it was judged that they share home range with urban residents at a time interval. In addition, according to the correlation analysis results between the mammal using rate of the urban ecological corridors and environmental factors(ecological corridor-specific length, ecological corridor-specific width, cover degree, shielding degree, connected green area, separation of movement routes, and presence of streetlights), environmental factors were not statistically significant. However, the more the area of green space connected to ecological corridors, the more increasing the mammal using rate of ecological corridor(r=0.71, p<0.05). Therefore, the area of green space connected to the ecological corridors that is associated with rate of wildlife using corridors should be considered as a priority when developing an urban ecological corridors. In the future, this study will extend the observation period of the ecological corridors and continuously accumulate data by adding the number of observation cameras. Furthermore, it is expected that the results of this study can be used as basic data for the standards for urban ecological corridors installation.

An Analysis for the Skill Mismatching of IT Service Sector by Technology Changes (기술변화에 따른 IT 서비스업의 숙련 미스매칭 분석)

  • Kim, Young-Dal;Jeong, Soon-Ki;Ahn, Jong-Chang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.273-282
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    • 2021
  • This study investigates for skills mismatching of the IT service sector in the flows of fast technology changes. It was conducted through an in-depth interview method for professional groups. There were differences in demand for skilled labor by business organizations and educators as providers of skilled labor. A five-point Likert scale was used. The degree of importance of 3.7 average point and the degree of satisfaction of 3.4 average point were responded for the set items in case of matching. In addition, the degree of importance of 3.79 average point and the satisfaction of 3.12 were responded in case of non-majored education students for IT. The skills desired from business organizations included multi-dimensional competencies and soft-skill items. For the reason of skills mismatching, business organizations presented ineffective specifications or divisions of the industrial manpower structure, and educational institutions selected the mismatching of time. Professional groups forecasted that the mismatching gap would expand in the future. To solve the gap, the participated professionals selected an industry-university institute collaboration course and gave an opinion to seek a method to foster manpower in the long-term perspective.