• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.63-76
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• 2008

The goals of this study are to develop travel time functions based on intersection delay and to analyze the applicability of the functions to traffic assignment models. The study begins with the premise that the existing assignment models can not effectively account for intersection delay time. In pursuing the goals, this study gives particular attention to dividing the link travel time into link moving time and stopped time at node, making the models based on such variables as the travel speed, volume, geometry, and signal data of signalized intersections in Cheongju, and analyzing the applicability of these models to traffic assignment. There are several major findings. First, the study presents the revised percentage of lanes (considering type of intersection) instead of g/C for calculating intersection delay, which is analyzed to be significant in the paired t-test. Second, the assigned results of applying these models to the Cheongju network in EMME/2 are compared with the data observed from a test car survey in Cheongju. The analyses show that the BPR models do not consider the intersection delay, but the modified uniform delay model and modified Webster model are comparatively well fitted to the observed data. Finally, the assigned results of applying these models are statistically compared with the test car survey data in assigned volume, travel time, and average speed. The results show that the estimates from the divided travel time model are better fitted to observed data than those from the BPR model.

• Journal of Environmental Science International
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• v.23 no.4
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• pp.605-613
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• 2014

In this work, the delay time for groundwater recharge was estimated by comparing simulated recharges by means of SWAT(Soil and Water Assessment Tool) model and WTF(Water Table Fluctuation) method. The delay time for groundwater recharge means that the time when the water from rainfall travelled through vadose zone just after getting out of soil zone bottom. As measuring this delay time is almost impossible, we used to compare the estimated values from modeling(SWAT) and analytic method(WTF). The test site is Hancheon watershed which has 8 groundwater measurement stations. The results show that the altitude has a linear relationship with the estimated delay time values. To validate these results, we conducted corelation analysis between transformed groundwater levels and observed ones. The results showed that computed groundwater levels have good corelation($R^2$=0.97, 0.87, respectively). The estimated delay time would be used for the groundwater behaviour characteristics in vadose zone. As recharge rates vary according to the height, the delay time is thought to be an import variable for the proper groundwater recharge estimation.

• Tunnel and Underground Space
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• v.6 no.1
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• pp.39-47
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• 1996

The results of the regression analysis and comparative study between 120 vibration events by dynamite blasting and 68 vibration events by finecker blasting which were monitored in the test blasting are as follows: The ground vibration velocity of dynamite blasting of 0.12 kg charge weight per delay at 7.4 m above the explosive is higher than that of finecker blasting of 0.96 kg charge weight per delay. In the case of 0.12 kg charge weight per delay, the ground vibration velocity of finecker blasting is equal to 5.5% of that of dynamite blasting at the 10 m distance from explosive. The decrement of ground vibration velocity of dynamite blasting of above 0.12 kg charge weight per delay is larger than that of finecker blasting of below 0.96 kg charge weight per delay. The rate of ground vibration velocity of the finecker blasting to that of dynamite blasting decreases with the distance from explosives, but increases with the decrease of charge weight per delay. The increment of ground vibration velocity of finecker blasting is less than that of dynamite blasting with the increase of charge weight per delay at the same distance from explosives. Under the condition of the constant critical ground vibration velocity or use the same charge weight per delay, the blasting working by finecker rather than by dynamite is able to be performed at the nearer place to structures.

• ETRI Journal
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• v.19 no.3
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• pp.259-280
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• 1997

This paper briefly explains the configuration of CDMA Mobile System (CMS) test bed. The measured fading and delay results of CDMA signal in Taejon area are shown. In comparison to other cellular systems, there are more parameters in the CDMA systems that affect system performance and capacity. We performed the optimization test of the selected parameters and present the effect of each parameter on the performance. This paper presents the capacity and performance test results of CMS. The capacity test was performed on ETRI site of three sectors in Taejon area. The performance tests include call completion rate, busy hour call attempt, and the delay characteristics of voice.

• Child Health Nursing Research
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• v.19 no.1
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• pp.12-20
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• 2013

Purpose: The purpose of this study was to investigate factors associated with suspicious developmental delay in infants and early childhood. Methods: Participants were 133 infants, aged from birth to 6 years old and their mothers, who were being seen at 16 Public health centers in B city. Korean Denver II was used to test infant development. ${\chi}^2$-test, Fisher's exact test and multiple logistic regression were used with SPSS 19.0 to analyze data. Results: Of participant infants, 7.5% were below the 3rd percentile for the weight percentile, 8.4% is a weight curve that crosses more than 2 percentile lines on the growth charts after previous achievement, and 9.8% had suspicious developmental delay according to Korean Denver II. Further the predictive factors related to suspicious development delay in the children were decrease of weight percentile (Odds Ratio [OR]=6.69, Confidence Interval [CI])=1.22-36.45), low economic state (OR=6.26, CI=1.50-26.00), and development delay perceived by their mothers (OR=4.99, CI=1.24-20.06). Conclusion: It is necessary to build a government level system to follow management of development of infants and children from the time of birth. Especially, it is necessary to develop a program for children in low income families.

• Explosives and Blasting
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• v.13 no.4
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• pp.39-46
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• 1995

This report was arrangemented and analysed by blasting previous instance of Nocsan, developing area of national factory town in Pusan since 1994. 11. our team have acquired sequential blasting machine which is used at open blasting sites of other countries. The result of study is that follow ; in case of delay electric detonator of Korea, it is possible to use 300 ~600 blasting holes in 2 charge per delay. But in our experience, it is best condition to use 100~200blasting holes at 1 charge per 1 delay.

• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.189-192
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• 2000

This paper presents a new DR(Dead Reckoning) algorithm in client-server-based networked virtual environment using network delay estimation. In the algorithm, a new update packet is sent to server (or client) whenever the difference of current real value and tracking value after network delay is larger than threshold. To confirm the proposed algorithm, a test network game was implemented. Through iterative field tests, we knew that this algorithm provides fair service and stability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.433-439
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• 2018

In this paper, a SDINS(strapdown inertial navigation system) rapid initial alignment technique with adaptive time delay compensation is proposed. The proposed method consists of two steps. In first step, misalignment and data latency are estimated by conducting pre-transfer alignment. Then, hybrid alignment is designed to rapidly find the misalignment changes induced by pyro-shock. To improve the performance of hybrid alignment, adaptive time delay compensation method is suggested. We verify the performance improvement of the proposed alignment scheme comparing with the conventional transfer alignment method by van test. The test result shows that the proposed alignment technique improves alignment performance.

• Korean Journal of Materials Research
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• v.18 no.9
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• pp.497-502
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• 2008

BGA test sockets failed earlier than the expected life-time due to abnormal signal delay, shown especially at the low temperature ($-50^{\circ}C$). Analysis of failed sockets was conducted by EDX, AES, and XRD. A SnO layer contaminated with C was found to form on the surface of socket pins. The formation of SnO layer was attributed to the repeated Sn transfer from BGA balls to pin surface and instant oxidation of fresh Sn. As a result, contact resistance increased, inducing signal delay. Abnormal signal delay at the low temperature was attributed to the increasing resistivity of Sn oxide with decreasing temperature, as manifested by the resistance measurement of $SnO_2$.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1840-1841
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• 2006

Plants with long time-delays can not be often controlled effectively using a simple PID controller. The main reason for this is that the additional phase lag contributed by the time-delay tends to destabilize the closed-loop system. The stability problem can be solved by smith predictor. However, in this case responses are very sensitive to the estimated model errors. To reduce sensitive problem, this paper is presented based on virtual reference feedback tuning of the time delay plant using the closed-loop test to find parameters for a PID controller using the closed-loop test data.