• Journal of Aerospace System Engineering
• /
• v.12 no.4
• /
• pp.35-48
• /
• 2018

The space qualification has to be conducted by a high level of screening to ensure the design margin of devices, materials, manufacturing processes, units, modules, and subsystem or system. The space qualification according to traditional test standards proposed by US military, NASA and ESA involve high cost and tight schedule due to their conservative requirements. It is necessary to develop a space qualification guideline that is cost-efficient and schedule-optimized for the development of domestic satellites. In this study, as a basic research to develop the space qualification guideline, the articles related to space qualification in test standards document released from military and space agency have been investigated. We are planning to utilize the results as a basic database for establishing the independent tailored space qualification guideline.

• Journal of Service Research and Studies
• /
• v.3 no.2
• /
• pp.45-52
• /
• 2013

With the development of information and communication technology, the Internet is more important in the social and economic influence rapidly, and it is no different in the field of health care. As health information on the Internet increasing, the availabilities of health information from the Internet becomes more important with health care professionals and information specialists. the quality of health information on the Internet are continually being presented without any guarantee or judge on the quality. It is needed to provide the right to use of qualified health information through Internet. HONCODE has been established and managed by HON (Health On the Net) Foundation. In this paper, Web sites of thyroid cancer Information are evaluated using HONCODE. They provide domestic medical information on the Internet. Through this, more accuracy and evaluated information could be provided on the Internet about the thyroid cancer.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.5
• /
• pp.655-667
• /
• 2009

An experimental study is performed on reducing the pollutants supplied by storm water through enhancing efficiency of SS from the detention storage tank where CSOs are kept temporarily before discharge to the receiving water system. SS removal efficiency is investigated in accordance with various conditions of the detention pond-such as its length, the existence of training wall, and the use of gravel filling. The removal efficiency is strongly affected by the detention pond's length until the critical falling distance of the suspended solids is reached. For cases where the tank has a length longer than this critical condition, the removal rate shows less sensitivity. To enhance the SS removal efficiency of tanks of shorter than the critical length, we studied alternative types of tank in which inside training walls are installed. The results showed improvement of 14 to 37% in removal efficiency in 2hours detention(2 training walls). The important factor in achieving a high SS removal rate is ensuring the critical length of the detention pond, but for the cases where the basin length cannot be guaranteed, baffles or a gravel filling scheme may be introduced to attain considerable efficiency. The results of studying and comparing different storage tank conditions show that, in terms of elimination efficiency, a storage tank with gravel filling and training walls > a storage tank with gravel filling > a storage tank with training walls > an empty tank. The experimental results should contribute to development of related further research, by empirically verifying the already assumed importance of critical falling distance, training walls, and gravel filling schemes.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.5
• /
• pp.547-555
• /
• 2009

The objectives of this research were focused on the effects of various operating parameters on nitrous oxide emission such as C/N ratio, ammonia concentration and HRT in the hybrid and suspension reactors. With the decreasing of C/N ratios, $N_2O$ emission rates in the both processes were increased because organic carbon source for denitrification was depleted. In case of biofilm reactor operated using medium, $N_2O$ release from the nitrification was not affected by the variation of ammonia concentration. But in the suspension reactor, $N_2O$ production from the nitrification was rapidly increased with the increase of ammonia. Nitrite accumulation caused by undesirable nitrification conditions could be a important reason for the increase in the $N_2O$ production from the aerobic reactor. And rapid increase in $N_2O$ production was reflected by the decrease of HRT, similar to the results observed in the results of ammonia loading changes. So it could be said that it is very important to put in consideration both its optimum conditions for wastewater treatment efficiency and suitable conditions for $N_2O$ diminish, simultaneously, in order to development an eco-friendly and advanced wastewater treatment, especially in BNR process.

• Journal of Korean Society of Transportation
• /
• v.18 no.3
• /
• pp.101-112
• /
• 2000

The Purpose of this Paper was to revise the method of USHCM and to establish new method for level of service analysis on two-lane rural highways. For this Purpose, total delay rate was selected as new MOE for level of service, replacing the present Percent time delay. This result showed that total delay rate was more effective for considering the effects of traffic flows, auxiliary lane, and vertical tirade. The application of total delay rate could resolve the Problems in the USHCM method, such as too wide ranges for level of service D and E, and the use of different Procedures for level of service analysis of general terrain segment and specific grade Procedures. The research results are as follows First, a new method for level of service analysis on two-lane rural highways was developed using the total delay rate. Second, a new classification for level of service was developed and a consistent method applicable for general terrain segment and specific tirade Procedures was developed. Third, the desired speed on two-lane rural highways was determined as 85km/h.

• Journal of Korean Society of Transportation
• /
• v.26 no.5
• /
• pp.101-115
• /
• 2008

This study reports UTIS(Urban Traffic Information System), which has been generalized in developed countries through brisk research and development and is being promoted for introduction by National Police Agency and Road Traffic Authority to reduce the astronomical amount of social expenses including traffic congestion expenses. Also this study investigates the proper charges for using by the preestimate of demand and contentment according to methods of payment after the service is introduced. The results of this study are as follows. First, demand forecast model is constructed by Binary Logit Model. Second, forecast models of using aspects of UTIS service according to methods of payment are established by Ordered Probit Model. Third, the proper charges for using of UTIS service according to methods of payment are presented to the supplier in the aspects of users. For this, preferences by using aspects and methods of payment are captured. And unit elasticity of coefficient of utilization is understood through responsiveness analysis according to methods of payment.

• Fisheries and Aquatic Sciences
• /
• v.1 no.1
• /
• pp.48-62
• /
• 1998

Seasonal volume transport on the Texas-Louisiana continental shelf is investigated in terms of objectively fitted transport streamfunction fields based on the current meter data of the Texas­Louisiana Shelf Circulation and Transport Processes Study. Adopted here for the objective mapping is a method employing a two-dimensional truncated Fourier representation of the streamfunction over a domain, with the amplitudes determined by least square fit of the observation. The fitting was done with depth-averaged flow rather than depth-integrated flow to reduce the root-mean-square error. The fitting process filters out $11\%$ of the kinetic energy in the monthly mean transport fields. The shelf-wide pattern of streamfunction fields is similar to that of near-surface velocity fields over the region. The nearshore transport, about 0.1 to 0.3 Sv $(1 Sv= 10^6\;m^3/sec)$, is well correlated with the seasonal signal of along-shelf wind stress. The spring transport is weak compared to other seasons in the inner shelf region. The transport along the shelf break is large and variable. In the southwestern shelf break, transport amounts up to 4.7 Sv, which is associated with the activities of the encroaching of energetic anticyclonic eddies originated in Loop Current of the eastern Gulf of Mexico. The first empirical orthogonal function (EOF) of streamfunction variability contains $67.3\%$ of the variance and shows a simple, shelf-wide, along-shelf pattern of transport. The amplitude evolution of the first EOF is highly correlated (correlation coefficient: 0.88) with the evolution of the along-shelf wind stress. This provides strong evidence that the large portion of seasonal variation of the shelf transport is wind-forced. The second EOF contains $23.7\%$ of the variance and shows eddy activities at the southwestern shelf break. The correlation coefficient between the amplitudes of the second EOF and wind stress is 0.42. We assume that this mode is coupled a periodic inner shelf process with a non-periodic eddy process on the shelf break. The third EOF (accounting for $7.2\% of the variance) shows several cell structures near the shelf break associated with the variability of the Loop Current Eddies. The amplitude time series of the third EOF show little correlation with the along-shelf wind.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.4
• /
• pp.1081-1094
• /
• 2014

The strut-tie model approach has proven to be effective in the ultimate analysis and design of structural concrete with disturbed regions. For the reliable analysis and safe design of the structural concrete, however, the effective strengths of concrete struts must be determined accurately. In this study, the equations of the effective strengths of concrete struts, which are useful for the three types of determinate and indeterminate strut-tie models of reinforced concrete corbels, were proposed. The effects of shear span-to-effective depth ratio, the vertical-to-horizontal force ratio, and flexural and horizontal shear reinforcement ratios were reflected in the development of the proposed equations. To examine the appropriateness of the proposed and existing equations, the ultimate strengths of 243 reinforced concrete corbels tested to failure were evaluated by using the three types of corbel strut-tie models.

• Spatial Information Research
• /
• v.12 no.3
• /
• pp.275-283
• /
• 2004

In order to effectively, and accurately assess seawater intrusion in coastal area, multidisciplinary data including geophysical, well logging, and hydrogeochemical data should be managed in systematical way. Such systematical management of data is critical key to improve the re-usability of the data as well as the accuracy of the assessment by means of providing a method of synthetic analysis. Therefore, for systematical management of multidisciplinary data in seawater intrusion problem, we have developed a database management system and 3-D visualization interface based on geographic information system in this, study. All geophysical survey, well logging, hydrochemical, as well as drilling, data are classified as attribute data using Microsoft Access, and joined with spatial information based on ArcView. The database management system and 3-D visualization interface to handle these data, also, developed using the script language of ArcView. We think the development of database and 3-D visualization system will improve the efficiency of data management, user-friendliness of data access, and accuracy of data analysis.

• Journal of Computational Design and Engineering
• /
• v.3 no.1
• /
• pp.37-52
• /
• 2016

To injection mould polymers, designing mould is a key task involving several critical decisions with direct implications to yield quality, productivity and frugality. One prominent decision among them is specifying sprue-bush conduit expansion as it significantly influences overall injection moulding; abstruseness anguish in its design criteria deceives direct determination. Intuitively designers decide it wisely and then exasperate by optimising or manipulating processing parameters. To overwhelm that anomaly this research aims at proposing an ideal design criteria holistically for all polymeric materials also tend as a functional assessment metric towards perfection i.e., criteria to specify sprue conduit size before mould development. Accordingly, a priori analytical criterion was deduced quantitatively as expansion ratio from ubiquitous empirical relationships specifically a.k.a an exclusive expansion angle imperatively configured for injectant properties. Its computational intelligence advantage was leveraged to augment functionality of perfectly injecting into an impression gap, while synchronising both injector capacity and desired moulding features. For comprehensiveness, it was continuously sensitised over infinite scale as an explicit factor dependent on in-situ spatio-temporal injectant state perplexity with discrete slope and altitude for each polymeric character. In which congregant ranges of apparent viscosity and shear thinning index were conceived to characteristically assort most thermoplastics. Thereon results accorded aggressive conduit expansion widening for viscous incrust, while a very aggressive narrowing for shear thinning encrust; among them apparent viscosity had relative dominance. This important rationale would certainly form a priori design basis as well diagnose filling issues causing several defects. Like this the proposed generic design criteria, being simple would immensely benefit mould designers besides serve as an inexpensive preventive cliché to moulders. Its adaption ease to practice manifests a hope of injection moulding extremely alluring polymers. Therefore, we concluded that appreciating injectant's polymeric character to design exclusive sprue bush offers a definite a priori advantage.