• Computers and Concrete
• /
• v.26 no.2
• /
• pp.161-173
• /
• 2020

Shear keys in precast concrete segmental bridges (PCSBs) are usually match-casting which is very labour intensive. In this research, an innovative match-casting-free construction was proposed by leaving small gap between the convex and the concave castellated shear keys in the joints of PCSBs. Specimen experiment, shear strength analysis and numerical simulation were conducted, investigating the loading performance of this new type of dry joints, the gap dry joints. Compared with match-casting joint specimens, it has been found from experiment that shear capacity of gap joint specimens significantly decreased ranging from 17.75% to 42.43% due to only partially constrained and contacted in case of gap dry joints. Through numerical simulation, the effects of bottom contacting location, the heights of the gap and the shear key base were analyzed to investigate strength reduction and methods to enhance shear capacity of gap joint specimens. Numerical results proved that shear capacity of gap dry joints under full contact condition was higher than that under partial contact. In addition, left contact destroyed the integrity of shear keys, resulting in significant strength reduction. Larger shear key base remarkably increased shear capacity of the gap joint. Experimental tests indicated that AASHTO provision underestimated shear capacity of the match-casting dry joint specimens, while the numerical results for the gap dry joint showed that AASHTO provision underestimated shear capacity of full contact specimens, but overestimated that of left contact specimens.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.1
• /
• pp.171-175
• /
• 2015

In this paper, because of global environmental problems such as energy shortage and abnormal climate, green energy development and energy saving technology development is being magnified. Heat insulation, the most basic and traditional energy saving method, is highly expected. Especially, simple and advanced heat insulation technique based on Nano material is promising future technology. The railway system also requires heat insulation. Especially, traditional heat insulator such as glass wool has been adopted frequently to rolling stock. The heat insulator is also adopted in general railway service buildings. Take account of cost-effective heat blocking performance, the heat insulator shall be adopted in diverse fields such as electric power, railroad, signal and communication. The only and direct solution for this problem is installing heat insulator with outstanding endurance, corrosion resistance and heat resistance to block outer heat Upgrading heat specification of equipment can be a solution, but since price and maintenance cost rise severely, this plan might be incongruous. In this research, energy saving effect of ultrathin heat insulator film was demonstrated by installing the film on roof of electrical room.

• Journal of Advanced Navigation Technology
• /
• v.14 no.5
• /
• pp.632-639
• /
• 2010

Ground Transportation is one of the most required field that users need positioning information Especially, more precise position can make smart traffic management possible and bring convenience to users. By advanced wireless network, cars can receive the GPS information of reference station in any tim e and any where. Thus land vehicles are possible to process precise positioning. In general, for precise positioning code and phase measurements are used. But receivers provide not only code and phase measurements but also doppler measurements and Doppler is direct measurement of velocity. In this paper, because velocity is very important information required in Ground Transportation, precise positioning for Ground Transportation is studied. For precise positioning RTK(Real-Time Kinematic) was used and double differenced doppler measurements were added, As a Result, positioning error by multipath and cycle slip was soften. However there still remained Positioning error. Thus smoothing technique using doppler measurement in position domain is used for softening positioning error.

• Journal of Korean Clinical Nursing Research
• /
• v.19 no.2
• /
• pp.218-232
• /
• 2013

Purpose: This study was aimed to describe Helicopter Emergency Medical Services (HEMS) and analyze the flight nurses' activities in HEMS. Methods: Data were collected retrospectively from the air transportation reports that contained data of 168 patients transported by aircraft to G University medical center in Incheon since June, 2012 to March, 2013. Data were analyzed using descriptive statistics, and Mann-Whitney U test. Results: Average distance of flights was 44.0 km, duration of field treatment took 13.6 minutes, and duration of a flight from scene to hospital was 14.5 minutes. Nursing activities were categorized into 12 direct nursing activities and 5 nursing management activities, and a total number of 7806 nursing activities were occurred in HEMS. The most frequently performed nursing activity was measurement and monitoring (27.9%) followed by medication (11.5%) and respiratory management (8.7%). The most frequent nursing management were information management (11.0%). Nursing activities performed were significantly different depending on the patient's level of consciousness, cause of illness, crew configuration, and type of transportation. Conclusion: This study described HEMS nursing activities performed by flight nurses. Difference in nursing activities according to patient characteristics, crew configuration and type of transportation requires flight nurses to be prepared through educational programs to improve nursing activities and nursing management during air transportation.

• Korean Chemical Engineering Research
• /
• v.50 no.6
• /
• pp.988-993
• /
• 2012

Energy and cost analysis of the preprocessing for carbon capture and storage transportation such as supercritical compression and liquefaction is done using chemical simulation model. Direct compression to supercritical phase (process 1-1), liquefaction and pumping (process 1-2), carbon dioxide compression and expansion as a refrigerant itself (process 2), usage of other refrigerant with compression and expansion (process 3-1), with absorption chiller (process 3-2), cascade refrigeration (process 3-2) have been simulated and evaluated. The specific cost is about 4 to 7 $/ton.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.3
• /
• pp.266-272
• /
• 2014

The Leadership in Energy and Environmental Design (LEED) Green Building Rating System provides third-party verification for environmentally sustainable construction. But while LEED-certified buildings provide healthier work and living environments, Previous studies have shown that LEED certification does not provide any direct economic incentives to owners and developers. To address this issue, this study aims to investigate the economic benefits of LEED criteria. The objective of this study is to examine whether or not there is a significant correlation between median household income and the number of bus stops and light rail stations for a given parcel that meet LEED sustainable site criteria for public transportation access. The findings showed that the number of bus stops had a positive correlation with median household income, which means that more bus stops a given parcel had that met LEED criteria, the greater the median household income of a block group where the given parcel was located would be, though this positive correlation was very weak.

• Journal of Information Technology Applications and Management
• /
• v.27 no.5
• /
• pp.69-80
• /
• 2020

Recently, luxury brands are selling their products to consumers using their own direct online channels. In the online channel, marketing strategy through storytelling is needed because consumers do not have enough product experience. Therefore, luxury brands are actively utilizing social media and delivering stories includes their birth and growth. Unlike mass media, social media communicates with consumers more quickly and frequently and delivers the story of brand naturally. This study classifies luxury brands into four groups based on story recognition of luxury brands and self-esteem, and analyzes and materializes each group of the propensities of luxury brand consumption. It also tries to draw strategic implications for effective SNS advertising by analyzing narrative transportation on SNS advertising, interests in videos, and the interests in story based on these typified groups of luxury consumption. The result of the analysis shows that there is a difference in consumption propensity among consumers who were classified into four groups according to story cognition of luxury brands and self-esteem. There is also a difference in the response to narrative images through SNSs, such as narrative transportation, interests in videos, and interests in brand stories.

• Journal of the Korean Society for Railway
• /
• v.11 no.5
• /
• pp.482-488
• /
• 2008

Seoul Metro Line 9 (SML9) will link Gimpo Airport to the Gangnam district opening in May 2009. SML9 has a new model in Korea constructed by metropolitan government and private company and operated by specialized public transportation service provider. SML9 is confronted with tough environment of stagnated public transportation and strong competitor, Olympic city expressway. Consequently SML9 must lead the maximum efficiency by using its material and human resource. Hereupon, I propose renovation plans from 3 viewpoints of operation field of SML9: Rapid-Local combination, close connection with other transportation and direct connecting service into Incheon Air-port Railroad(AREX).

• The Journal of Asian Finance, Economics and Business
• /
• v.10 no.2
• /
• pp.235-245
• /
• 2023

This study examines the low performance of state civil servants related (ASN) to the management of public transportation at the Directorate of Road Transport (DRT), Ministry of Transportation, Indonesia. This study surveyed 103 ASNs, using a quantitative approach using the Amos SEM software. The results showed that Knowledge Sharing (KS) and Work Engagement (WE) directly influenced Innovative Work Behavior (IWB) as well as Job Performance (JP). Meanwhile, IWB had a significant, direct effect on JP and acts as a full mediator in the effect of KS and WE on JP. The descriptive data obtained also showed that respondents' statements based on gender have differences related to the IWB variable, where on average, women were better than men. However, for other variables (JP, KS, and WE), the data showed that, on average, the statements of male respondents were better than women. This study recommends that the DRT pay attention to IWB as a key factor mediating KS and WE towards increasing JP by maintaining the best indicators and improving the weakest indicators. Furthermore, this study recommends that future research refine these results by adding the variables of gender and educational level of the respondents.

• Industrial Engineering and Management Systems
• /
• v.11 no.2
• /
• pp.148-154
• /
• 2012

Micro Electric Vehicles are considered as a solution for reducing $CO_2$ emissions, however, it is difficult to evaluate its impact in a local community when it has been introduced. In this study, we evaluated how to spread the Micro EV within the community, using the utility derived from a multinomial logit model, and analyze the effect on $CO_2$ emissions. The householder's utility model is based on an investigation about Kiryu citizen's activities of shopping, transportation methods, etc. Using the geographic information system, we get the distances of each householder and the stores, and estimate a multinomial logit model about the combination choices of shopping stores and transportation method.