• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.169-178
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• 2008

Level of Service (LOS) is one of ways to evaluate operational conditions. It is very important factor in evaluation especially for the facility of highways. However, some studies proved that ${\upsilon}/c$ ratio and accident rate is appeared like a second function which has a U-form. It means there is a gap between LOS and safety of highway facilities. Therefore, this study presents a method for evaluation of a signalized intersection which is considered both smooth traffic operation (delay) and traffic safety (accident). Firstly, as a result of our research, accident rates and EPDO are decreased when it has a big delay. In that reason, it is necessary to make a new Level of Service included traffic safety. Secondly, this study has developed a negative binominal regression model which is based on the relation between accident patterns and stream. Thirdly, standards of LOS are presented which is originated from calculation between annual delay costs and annual accident cost at each intersection. Lastly, worksheet form is presented as an expression to an estimation step of a signalized intersection with traffic accident prediction model and new LOS.

• The KIPS Transactions:PartC
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• v.16C no.6
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• pp.791-800
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• 2009

Multicasting is fundamental to many ad hoc network applications requiring collaboration of multiple nodes in a group. A general approach is to construct an overlay tree and to deliver a multicast packet to multiple receivers over the tree. This paper proposes adaptive overlay trees (AOTs) on wireless ad hoc networks of static nodes for delay- and energy-efficient multicast. A tradeoff function is derived, and an algorithm for AOT construction is developed. Note here that the requirements of delay and energy consumption may vary with different classes of applications. By adjusting parameters in the tradeoff function, different AOTs can be adaptively chosen for different classes of applications. An AOT is constructed in O(ke) time where e is the number of wireless links in a network and k is the number of member nodes in a multicast group. The simulation study shows that AOT adaptively provides tradeoffs between the fastest multicast (which is the choice if delay is the most important factor) and the most energy efficient multicast (which is used when energy consumption is the primary concern). In other words, one of AOTs can be appropriately chosen in accordance with the operation requirement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.680-687
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• 2018

Borehole radar is a radar used for underground resources and geological exploration purposes. It needs a high-speed sampler to transmit electromagnetic waves with a pulse width of several ns and to receive reflected waves of several tens to several hundreds of MHz reflected from the object to be surveyed. ETS (Equivalent-Time Sampling), which can achieve sampling performance of several GHz with a sampling frequency of several tens of MHz, is suitable for use as a sampler of a borehole radar receiver. In this paper, we propose a method to control the sampling clock delay, which is the most important factor in ETS sampler design, using four clocks with phase difference of $90^{\circ}$ for one clock source. The proposed method can reduce the time required to acquire the data within the set interval by 1/25 than the conventional method using the delay generator. When the implemented sampler is applied to the receiver of existing borehole radar, it is possible to accumulate 58 additional times due to the shortened sampling time. In addition, by using one delay control logic compared with the conventional method using several sampling clock delay control logic in order to satisfy the target sampling range, it is possible to omit the correction process which was necessary in the past. As a result, the structure of the system can be simplified and a uniform sampler can be realized.

• Journal of Navigation and Port Research
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• v.36 no.6
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• pp.475-480
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• 2012

In order to establish eLoran (enhanced Long Range Navigation) system, it needs the advancement of receiver, transmitter, data channel addition for Loran information, differential Loran sites for compensating Loran-c signal and ASFs (Additional Secondary Factors) database, etc. In addition, the precise synchronization of transmitting station to the UTC (Coordinated Universal Time) is essential if Loran delivers the high absolute accuracy of navigation demanded for maritime harbor entrance. For better timing synchronization to the UTC among transmitting stations, it is necessary to measure and monitor the transmission delay of the station, and the correction information of the transmitting station should be provided to the user's receivers. In this paper we presented the measurement method of absolute delay of Pohang Loran transmitting station and developed a time delay measurement system and a phase monitoring system for Loran station. We achieved -2.23 us as a result of the absolute phase delay of Pohang station and the drift of Loran pulse of the station was measured about 0.3 us for a month period. Therefore it is necessary to measure the delay offset of transmitting station and to compensate the drift of the Loran signal for the high accuracy application of PNT (Positioning, Navigation and Timing).

• Journal of Cadastre & Land InformatiX
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• v.53 no.2
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• pp.67-77
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• 2023

As cities become overcrowded and concentrated, the demand for public services continues to increase due to the improvement of the living standards of urban residents. Among them, fire service can be seen as one of the important public services by reducing damage caused by accidents in emergency situations and affecting the improvement of access to medical services for urban residents. Rapid movement of patients and medical institutions within golden time and proper first aid are essential elements in emergency situations, and Seoul is a super-large city with a large population of about 10 million people and has a large number of emergency medical patients. Therefore, this study used spatial regression analysis to examine the factors affecting the delay factors of emergency dispatch in Seoul to secure golden time, and derived management priorities, and suggested implications for the management of emergency vehicle dispatch delay factors. As a result of the main analysis, land-use characteristics were the most influential factor in emergency vehicle dispatch time, and land-use mixing, commercial area density, average patient age, and average road length were found to affect emergency vehicle dispatch time in order. This study can be used as important basic data for an accurate understanding of the delay factors for emergency dispatch and preparing countermeasures according to priorities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.379-390
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• 1994

The recent study of the delay models have assumed random arrival which has a constant average flow rate throughout the cycle. However, where signals are spaced closely together or form part of progressive system, platoon flows are common and more closely represent reality. In such cases, those results are quite different pattern of estimated delay from that of observed one. In order to solve this problem, the 1985 HCM takes Progression Adjustment Factor (PAF) into account. In the 1985 HCM, however, it has deficiencies in defining and applying it, such as platoon ratio ($R_p$) and platoon arrival type. The Purpose of this study is to investigate theoretically the predictive ability of the individual models concerned through comparing the estimated delay and PAF suggested by NCHRP Report 339, KHCM or USHCM (1985) with the observed obtained by field survey at a signalized intersection.

• Journal of the Korean Society of Costume
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• v.66 no.4
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• pp.32-44
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• 2016

The purpose of this study is to examine the cognitive responses and the corresponding behavior responses of consumers who have experiences in not being able to buy a product in an online shopping mall due to it being sold-out. Responses were gathered from 526 consumers between the ages of 20 to 40 years residing in a metropolitan area. Each person surveyed had experienced a situation in which a product that they wanted to purchase from an online shopping mall was sold-out. SPSS 18.0 was used to perform frequency analysis, factor analysis, reliability analysis, and regression analysis. The first set of results of this study showed positive responses of quality, discernment, scarcity, but also negative cognitive responses of careless management, manipulation of shopping mall management, and common taste. In negative cognitive responses, sold-out situations caused consumers inconvenience. The second set of results revealed that quality, discernment, and careless management had a significant effect on product replacement (Substitute, S); likewise, factors such as quality, discernment, careless management, manipulation by shopping mall designers, and common taste had a significant effect on the delay of purchasing decisions (Delay, D). Scarcity, careless management, manipulation by shopping mall designers, and common taste also demonstrated significant influence on the incomplete leaving of stores (Incomplete Leave, L1), while discernment, scarcity, careless management, manipulation by shopping mall designers, and common taste had a significant influence on the complete leaving of stores (Complete Leave, L2). Previous studies have examined the behavioral response topics of substitute, delay, and leave. These study results suggest that product sellouts at online shopping malls did not have a solely negative effect on consumers. It actually had a positive effect in terms of discernment, scarcity, and the perception of quality of sold-out products. Furthermore, both positive and negative cognitive responses had various effects on behavioral responses.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.23-31
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• 2002

The headway of vehicles entering an intersection is closely related with the saturation flow rate and is a basic parameter required for determining the saturation headway and the start-up lost delay. Since such headway value reflects the drivers' behaviors and features of the intersection, all intersections don't have an equal value, but are affected by number and location of their lanes, changing types, local characteristics and time zone. Accordingly, this study attempted to suggest proper values on the basis of data by investigating headway in lanes. Number of exclusive through lanes was divided into single lane, double lanes and triple lanes, the locations of lanes were divided into inside lane, central lane and outside lane. As a result of investigating the headway, single through lane, double through lanes-inside lane, and triple through lane-outside lane showed as 1.73 sec., 1.71 sec. and 1.93sec., respectively. The result of calculating the area factor of business areas by fixing 1.00 for the residental area and applying relation between headway and saturation flow rate was 0.96. In the case of start-up lost delay lead dual left turn and directional separation were 1.41 sec. and 3.27 sec., respectively, showing the great difference. Therefore, different start-up lost delay according to changing type should be applied.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.29-35
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• 2017

This paper presents a high-throughput area-efficient mixed-radix fast Fourier transform (FFT) processor using the efficient scheduling schemes. The proposed FFT processor can support 64, 128, 256, and 512-point FFTs for orthogonal frequency division multiplexing (OFDM) systems, and can achieve a high throughput using mixed-radix algorithm and eight-parallel multipath delay commutator (MDC) architecture. This paper proposes new scheduling schemes to reduce the size of read-only memories (ROMs) and complex constant multipliers without increasing delay elements and computation cycles; thus, reducing the hardware complexity further. The proposed mixed-radix MDC FFT processor is designed and implemented using the Samsung 65nm complementary metal-oxide semiconductor (CMOS) technology. The experimental result shows that the area of the proposed FFT processor is 0.36 mm2. Furthermore, the proposed processor can achieve high throughput rates of up to 2.64 GSample/s at 330 MHz.

• The Journal of the Korea Contents Association
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• v.2 no.4
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• pp.51-58
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• 2002

A electronic business user is increased rapidly, and load of a electronic business system and network traffic are increased rapidly. Also, the data which included an audio and video is increasing in a electronic business system gradually, and According to this an Internet service businessman is paying for an enormous cost for management of a system and a maintenance of a line. It is brought a delay of a response speed about a service wish of a Web customer this system load and network traffic raise. Also, this decreases customer satisfaction and becomes an important factor to decrease competitive power of an e-business enterprise. In this study, we proposed the electronic business system that improved answer delay time about a Web customer in an e-business system based on the .net which was a the latest version of Microsoft company, and analyzed performance of a proposal system through an experiment. In the experiment result, the system that proposed it can have response time to have been improved and fast adaptability about various requests of a Web customer. Also, in a proposed system, a decrease gets a delay of a response speed to occur because of the multiple user done.