• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.63-75
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• 2013

Roundabouts have been operated in Europe, America and Australia since the 1970s, and many relevant researches continually was carried out. Though many studies regarding roundabout have been recently conducted in korea, most of them have focused on its operational safety and efficiency. Moreover, roundabout design guideline did not define a clear criteria related to pedestrian in roundabout, but seldom investigate the influences of pedestrian on crosswalk. In this study, we seek ways to operate the pedestrian crosswalk signal on roundabout maximizing their operational effects in exceptional case such as rush hour or intersection near the special facilities. We proved that roundabout signal operation is effective under certain circumstances in according to the number of pedestrian, and suggested the optimal signal timing plan for signalized roundabouts. For pursuing the above, we conducted the simulation test using the VISSIM model. The results show that the operational effectiveness of signalized roundabout was evaluated to be better than non-signalized roundabout in specific pedestrian volume condition. In addition, those results are confirmed using simulation analysis conducted on the real roundabout.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.677-685
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• 2015

In a will to subdue the brittleness as well as the low tensile and flexural strengths of ordinary concrete, researches are being actively watched worldwide on steel fiber-reinforced Ultra High Performance Concrete (UHPC) obtained by admixing steel fibers in ultra high strength concrete. For the purpose of maximizing advantage of UHPC, this study removes the upper flange of the steel girder to apply an inverted T-shape girder for the formation of the composite beam. This paper intends to evaluate the behavior of the shear connectors and the flexural characteristics of the composite beam made of the inverted T-shape girder and UHPC slab using 16 specimens considering the compressive strength of concrete, the mixing ratio of steel fiber, the spacing of shear connectors and the thickness of the slab as variables. In view of the test results, it seemed that the appropriate stud spacing should range between 100 mm and 2 or 4 times the thickness of the slab. Moreover, the relative displacement observed in the specimens showed that ductile behavior was secured to a certain extent with reference to the criteria for ductile behavior suggested in Eurocode-4. The specimens with large stud spacing exhibited larger values than given by the design formula and revealed that the shear connectors developed larger ultimate strength than predicted owing to the action of UHPC and steel after non-composite behavior. Besides, the specimens with narrow stud spacing failed suddenly through compression at the upper chord of UHPC before reaching the full capacity of the shear connectors.

• The Journal of Korean Academy of Sensory Integration
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• v.13 no.2
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• pp.53-61
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• 2015

Objective : The purpose of this study was to investigate the effects on sensory integration interventions for korean children which focused on vestibular - proprioceptive system. Methods : Authors systematically searched published studies in DBpia, KISS and RISS databases from August to September 2015. Key words in the search were 'sensory integration intervention', 'sensory integration therapy' and 'vestibular-proprioceptive'. By using the inclusion and exclusion criteria, we selected seven studies for further analyses examining level of evidence and methodological qualities. Information for the analyses were on study designs, participants, interventions, outcome measures and results. Results : Grade IV rated evidence was found from five studies, and Grade III and Grade V rated evidence was found from one for each study. The methodological levels of the quantitative studies were 'fair' (2) and 'poor' (5). Subjects for the studies were developmental delay (5), Asperger Syndrome (1), and not specific diagnosis (2). Single-subject design was most frequently used and motor area were most frequently evaluated. The interventions used the studies showed positive effects on outcome measures. Conclusion : This study presented the summary of sensory integration intervention based on vestibular-proprioceptive system for Korean children. More studies with high level of evidence and various study designs need to be followed.

• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.37-47
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• 2011

This paper describes the stability evaluation of reinforced earth wall with steel framed-facing based on field test. The reinforced earth wall with steel framed-facing is composed of wall facing, reinforcement and backfill soil. The wall facing is assembled by steel frames and the aggregates are filled in that. The reinforcement is steel strip type based on bearing resistance. Field test is conducted to evaluate for two separate sections and the measurement is conducted according to construction elapsed time of structure for earth pressure, horizontal displacement of wall facing and reinforcement strain. The evaluation results show that the measured earth pressure is less than theoretical earth pressure due to dispersion effect of earth pressure by the applied reinforcement. Also, the horizontal displacement of wall facing satisfied a empirical criteria and the measured strain of reinforcement had nearly no effect on stability of structure. Therefore, the reinforced earth wall with steel framed-facing has a structural stability and it can be commonly used in field.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.5125-5135
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• 2015

Background: Total fat intake may be associated with increased risk of breast cancer, and fish oil has been suggested as a protection factor to breast cancer. But the effect of vegetable oils is inconclusive. We aimed to investigate the association with high vegetable oils consumption and breast cancer risk, and evaluated their dose-response relationship. Design: We systematically searched the MEDLINE, EMBASE, Cochrane databases, and CNKI updated to December 2014, and identified all observational studies providing quantitative estimates between breast cancer risk and different vegetable oils consumption. Fixed or random effect models were used to estimate summary odds ratios for the highest vs. lowest intake, and dose-response relationship was assessed by restricted cubic spline model and generalized least-squares trend (GLST) model. Results: Five prospective cohort studies and 11 retrospective case-control studies, involving 11,161 breast cancer events from more than 150,000 females, met the inclusion criteria. Compared with the lowest vegetable oils consumption, higher intake didn't increased the risk of breast cancer with pooled OR of 0.88 (95% CIs:0.77-1.01), and the result from dose-response analyses didn't show a significant positive or negative trend on the breast cancer risk for each 10g vegetable oil/day increment (OR=0.98, 95% CIs: 0.95-1.01). In the subgroup analyses, the oils might impact on females with different strata of BMI. Higher olive oil intake showed a protective effect against breast cancer with OR of 0.74 (95% CIs: 0.60-0.92), which was not significant among the three cohort studies. Conclusions: This meta-analyses suggested that higher intake of vegetable oils is not associated with the higher risk of breast cancer. Olive oil might be a protective factor for the cancer occurrence among case-control studies and from the whole. Recall bias and imbalance in study location and vegetable oils subtypes shouldn't be ignored. More prospective cohort studies are required to confirm the interaction of the impact of vegetable oils on different population and various cancer characteristic, and further investigate the relationship between different subtype oils and breast cancer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5B
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• pp.467-474
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• 2011

Debris flow is one of the most hazardous natural processes in mountainous regions. The degradation of discharge capacity of drainage facilities due to debris flows may result in damages of properties and casualty as well as road. Understanding and accurate reproducing flow behaviour of debris flows at various conditions, such as sediment volume concentration and approaching channel and culvert slopes, are prerequisite to develop advanced design criteria for drainage facilities to prevent such damages. We carried out a series of laboratory experiments of debris flows in a rectangular channel of constant width with an abrupt change of bottom slope. The experimental flume consists of an approaching channel part with the bed slope ranging $15^{\circ}$ to $30^{\circ}$ and the test channel with slope ranging from $0^{\circ}$ to $12^{\circ}$ which mimics a typical drainage culvert. The experiments have been conducted for 22 test cases with various flow conditions of channel slopes and sediment volume concentration of debris flows to investigate those effects on the behaviour of debris flows. The results show that, according to sediment volume concentration, the depth of debris flow is approximately 50% to 150% larger than that of fresh water flow at the same flow rate. Experimental results quantitatively present that flow behaviour and deposit history of debris flows in the culvert depend on the slopes of the approaching and drainage channels and sediment volume concentration. Based on the experimental results, furthermore, a logistic model is developed to find the optimized culvert slope which prevents the debris flow from depositing in the culvert.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.300-309
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• 2005

The purpose of this study is to design internet CEDA (Cross Examination Debate Association) debating model for the internet-based learning. Comparing to open discussion model that is widely spreaded in regular classes, the CEDA model can enhance learner's thinking skills, logicality, analytic skills, and judgement ability. In the first study, 196 students were provided the specific CEDA model guideline and participated debate activities through the internet. The results of the students' debate were analyzed based on the evaluation criteria. The results showed that the students' evaluation scores were high overall. They favored the CEDA model over the open discussion model, and showed positive attitudes and perceptions on the CEDA internet debate activity. In the second study, another 200 students were participated in two different tutor supporting CEDA debating groups, one is advanced tutor strategy group and the other is general tutor strategy group. The results showed that the advanced tutor supporting group had significantly high scores on the cross examination and providing evidence on debating. This study finally suggests the CEDA internet model for general use. In conclusion, this study also suggests the next steps to elaborate the CEDA internet model not oかy for the university settings, but also for general school settings. The user manuals should be developed to assist instructors, students, and tutors to guide better debate activities through the internet CEDA class. Also further research should be conducted to provide various debate models and applications for the variety of learning environments, and so the schools to use the CEDA model more widely in the internet classes.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.320-332
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• 2013

The feed air to MSW incinerator influences on the residence time of combustion gas, removal of unburnt ash and exiting gas temperature. Thus the secondary air volume could present sufficient residence time which can maintain the exiting temperature over $850^{\circ}C$. The secondary air also relates directly with the turbulence in the inside of combustion chamber, which finally provide the stable combustion condition. The present study designed a modern incinerator for a field scale, and evaluation of the potential amount of primary air based on the daily combustible quantity. From the evaluated primary air volume, the secondary air flow rate could be estimated, and its dynamic behavior was verified. In addition, the obtained air volume enables to find an optimum operation condition of the combustion. As a result of the CFD simulation, the air ratio 75 : 25 between primary and secondary air amount was optimum ratio than design criteria 72 : 28. And the flow velocity ratio of front-back of secondary air jet nozzle was found excellent at 1 : 3. In addition, the result of applied to the plant, the removal efficiency of NOx and CO generation would concentration of CO.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.3
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• pp.69-78
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• 2013

Objectives The purpose of this study was to investigate the effectiveness of the Gongjin-dan (Gongchen-dan, here in after GJD) in order to obtain the evidence for clinical application. Methods The GJD-related articles published from 1990 to 2013 were searched using "Korean Traditional Knowledge Portal", "Oriental Medicine Advanced Searching Integrated System (OASIS)", "Korean Association of Medical Journal Edition (Koreamed)", "Research Information Services (RISS4U)", "Korean Medicine Database (KMbase)", "National Discovery for Science Leader (NDSL)", "PubMed", "China National Knowledge Infrastructure (CNKI)". The search keywords were "Gongjin-dan", "Gongchen-dan". Thirty-nine articles were obtained. After excluding the eighteen article which did not meet inclusion criteria, finally twenty-one articles were included; five clinical articles and sixteen experimental articles. Results In clinical studies, GJD has the various effectiveness in cardiovascular diseases, alcoholic hepatitis, mild dementia, anemia. Also experimental studies related to the GJD show a variety of effects, such as anti-oxidative activity, neuroprotective activity, hepatoprotective activity, anti-inflammatory activity, immunological activity, reproductive recovery activity with fewer side-effects. Conclusions It has been suggested that there are various effects of GJD in treating a wide-range disease. However, in order to put GJD to use for many kinds of diseases in more reasonable ways, it is needed to publish well-design clinical trial based on the variety of results of experimental studies.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.6
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• pp.1-12
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• 2012

This study aims to suggest ways to improve sustainability on housing complexes. This study sampled eight housing projects in Seoul and GyeongGi-Do in Korea, which were completed in June 2007 and June 2008. Then, are retention and maintenance on "constructed greens for ecological environment" including "green structures substitutes retaining walls", "green roofs", and "green walls." Study methods are field investigations of the sampled sites, and Post Occupancy Analysis. Major findings were; 1) "constructed greens" are not well retained in more sites and and this implies the GBCS(Green Building Certification System) does not meet its objectives well, 2) User showed lower user satisfaction to "constructed greens". User satisfaction concerning "green structures substitute retaining walls" was higher than the satisfaction on the other constructed green type. Satisfaction Assessment Criteria lower 1han average were "level of quality", "meet the design objectives", "vegetation management status", "vegetation maintenance". 3) User satisfaction was strongly correlated on the level of quality factor of "constructed green". In addition, tue other factors are the significant correlations between the satisfactions. The present GBCS has inadequate assessment standards for maintenance, which lead to lower the entire satisfaction. Therefore, periodic recertification system, education and information providing for the managing personals, and incentives for good maintenance or disincentive for poor maintenance of the "constructed greens" are suggested to improve the GBCS.