• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.10
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• pp.895-902
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• 2012

In this paper, we propose a novel equalizer to compensate for the group delay including AM/PM nonlinear distortion characteristics by the nonlinear power amplifier (PA). The group delay characteristic is a nonlinear non-constant time delay that appears differently depending on each frequency component. The phase distortion by AM/PM characteristics arising from the power amplifier is a major factor to increase group delay. By the group delay distortion, the signal in the constellation expands and is rotated. Considering the problem mentioned above, the nonlinear time delay that appears differently depending on each frequency component is classified as a static group delay and AM/PM characteristic of PA, the different phase transitions depending on the size of input signal as a dynamic group delay. Static group delay estimates and compensate for phase distortions in the frequency domain with type-based method and dynamic group delay compensates for phase rotation in the time domain. We confirmed that the group delay compensation techniques were enough to compensate the group delay characteristics including AM/PM characteristics of the power amplifier.

• Korean Journal of Childcare and Education
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• v.1 no.1
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• pp.167-189
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• 2005

The purpose of this study was to examine the relationships among delay gratification, delay strategy, and parents' child-rearing attitude. The participants of the study were 62, 18-36 month old infants, who demonstrated individual differences in the level of delay gratification and their mothers. The instruments of the study were infant's delay gratification and delay strategy were assessed by Mischele(1974) and the parents' responded to the parents' child-rearing attitude(Cho et al., 1999). Data were collected by menas of conducting observations on infants in experimental settings and completing questionnaires with mothers. The results of this study were as follows: 1. The delay gratification of infants differed accordingly to their age. Older infants displayed increased time in showing their delay gratification, while younger infants relatively exhibited shortened time. There was no significant difference in infants' sex and the order of the birth. 2. Following the age factor, the distraction strategy in the delay strategy played a significant difference to infants. Older infants required a frequent use of the distraction strategy in comparison to younger infants. 3. The previous two factors - delay gratification and distraction strategy-showed a positive relationship. 4. The delay gratification was significantly influenced by infants' age, parents' attitude, direct facing strategy, and infants' distraction strategy. However, the delay gratification was insignificantly accounted for by infants' sex.

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.362-379
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• 2015

In this study, Nuclear Power Plant (NPP) construction schedule delay risk assessment methodology is developed and the construction delay risk is assessed for turnkey international NPP projects. Three levels of delay factors were selected through literature review and discussions with nuclear industry experts. A questionnaire survey was conducted on the basis of an analytic hierarchy process (AHP) and Relative Importance Index (RII) methods and the schedule delay risk is assessed qualitatively and quantitatively by severity and frequency of occurrence of delay factors. This study assigns four main delay factors to the first level: main contractor, utility, regulatory authority, and financial and country factor. The second and the third levels are designed with 12 sub-factors and 32 sub-sub-factors, respectively. This study finds the top five most important sub-sub-factors, which are as follows: policy changes, political instability and public intervention; uncompromising regulatory criteria and licensing documents conflicting with existing regulations; robust design document review procedures; redesign due to errors in design and design changes; and worldwide shortage of qualified and experienced nuclear specific equipment manufacturers. The proposed combined AHP-RII methodology is capable of assessing delay risk effectively and efficiently. Decision makers can apply risk informed decision making to avoid unexpected construction delays of NPPs.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.298-298
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• 1998

The delay on two-lane, Two-way roads is a very important factor which tends to cause relatively high driver loads and too much delay often leads to traffic accidents. In this study a generalized form of delay estimation model was developed based on constant slow moving vehicle speeds, 100% no-passing zone, and flat terrain highway sections. To validate the model, a comparison was made with John Morrall's SMV(Slow Moving Vehicle)model as well as with TWOPAS model. Also a sensitivity analysis was performed to check accuracy of the model. It was found that the model was easy to apply and yet provided reasonable results for experimental conditions specified in the study. It was recommended that speed calculation procedure of the model be improved by further studies, so that the effect of speed acceleration or deceleration according to highway geometries on delay could be analyzed more accurately.

• Journal of Communications and Networks
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• v.6 no.4
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• pp.352-361
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• 2004

In this paper, we study how to achieve the maximum capacity under delay constraints for large mobile wireless networks. We develop a systematic methodology for studying this problem in the asymptotic region when the number of nodes n in the network is large. We first identify a number of key parameters for a large class of scheduling schemes, and investigate the inherent tradeoffs among the capacity, the delay, and these scheduling parameters. Based on these inherent tradeoffs, we are able to compute the upper bound on the maximum per-node capacity of a large mobile wireless network under given delay constraints. Further, in the process of proving the upper bound, we are able to identify the optimal values of the key scheduling parameters. Knowing these optimal values, we can then develop scheduling schemes that achieve the upper bound up to some logarithmic factor, which suggests that our upper bound is fairly tight. We have applied this methodology to both the i.i.d. mobility model and the random way-point mobility model. In both cases, our methodology allows us to develop new scheduling schemes that can achieve larger capacity than previous proposals under the same delay constraints. In particular, for the i.i.d. mobility model, our scheme can achieve (n-1/3/log3/2 n) per-node capacity with constant delay. This demonstrates that, under the i.i.d. mobility model, mobility increases the capacity even with constant delays. Our methodology can also be extended to incorporate additional scheduling constraints.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.125-129
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• 2010

The ultimate goal of construction is to complete the given work in the most economical and safest way within the required construction period while meeting the quality standards specified in the design drawing. There are a few characteristics of finish work. First, executed in subdivided processes, finish work involves a very diverse and complex structure. Second, there are no criteria for each segmented process with regard to the appropriate time of input. Third, it is not very necessary to set priorities for lead and lag works. This study intends to provide information on the completion of a project in accordance with the required duration by setting priorities in the delay of each detailed process of finish work to minimize delay in finish work. In this study, finish work is divided into wet work and other types of finish work, and the importance of each process is classified based on the given details of each process. In addition, the study employs a survey to analyze delay factors of a designer, a constructor, and a supplier. Using the survey results, the study sets priorities in delay of final work to provide information on the completion of an apartment project within the planned construction period.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.12
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• pp.1690-1696
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• 2014

Network RTK generates spatial corrections by using differenced measurements from reference stations in the network, and the corrections are then provided to a rover. The rover, generally, uses linear interpolation, which assumes that the corrections at each reference station are spatially correlated, to obtain a precise correction of its location. However, an irregularity of the tropospheric delay is a real-world factor that violates this assumption. Tropospheric delay is a result of weather conditions, such as humidity, temperature and pressure, and it can cause spatial decorrelation when there are changes in the local climate. In this paper, we have defined the non-linear characteristics of the tropospheric delay between reference stations or user within a region as the "irregularity of tropospheric delay". Such an irregularity can negatively impact the network RTK performance. Therefore, we analyze the influence of the irregularity of tropospheric delay in network RTK based on meteorological data.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.496-501
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• 2006

Work delay is the one of facts that make the reliability of construction business decrease. Building a causal classification system of work delay and deducing the managemental item for it gives a great competition to the construction industry. It is, however, so rare to study about work delay so far. Therefore, this research analyzed a questionnaire, which is focussing on the public apartment construction, to look into the causal root factors and deduce the work delay factors. Finally, we suggest a major managing point to remove effectively the work delay factors.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.5
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• pp.766-776
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• 2008

The purpose of this study was 1) to identify the reasons for delay of decision making and the shopping information in internet shopping, 2) to classify consumers based on the clothing benefits, 3) and to examine the differences among consumer groups in the reasons for delay of decision making and the shopping information. The data were collected from a sample of 500 internet shopper aged from 20 to 40. This study used factor analysis, multiple regression analysis, Pearson's correlation analysis, cluster analysis and ANOVA. The results showed that the reasons for delay of decision making consisted of eight factors: Performance risk, Comparison shopping, Economic shopping, Social risk, Uncertainty, Expecting of market change, Product unsatisfaction, Passive shopping. The shopping information consisted of three factors: Product variety, Product information, Additional information. Five factors of clothing benefits were Economy, Figure compensation, Social position, Individuality, and Comfort. The respondents were classified into four groups by five factors of clothing benefits; Individuality seeking group, Low-benefits seeking group, Economy seeking group, Figure compensation/comfort seeking group. There were significant differences among groups in the reasons for delay of decision making and the shopping information among groups. Therefore, marketers need to provide different shopping information for delay closure by target groups.

• The Journal of Economics, Marketing and Management
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• v.6 no.1
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• pp.9-16
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• 2018

Purpose - Benefit delay type services have a characteristic of benefit delay that does not immediately appear at the time of delivery of service. Due to a characteristic of benefit delay, the customer's participation in the service delivery system is hindered, and the quality of service declines. As a result, customer satisfaction would be reduced. The purpose of this study is to construct an analytical framework to analyze a mechanism that promotes customer participation in benefit delay type services. Research design, data, and Methodology - Existing research has considered only the performance of service companies to enhance the quality of service and customer satisfaction. This study focused on customer participation as a factor affecting the quality of service and customer satisfaction and attempted to construct an analytical framework based on a theoretical perspective of motivational research. Results - By adopting the motivation theory, this research derived three concepts, the possibility of gaining benefits, the emotional experience, and the desire of benefit. And motivation is created when the three factors interact with each other. Conclusions - This paper has constructed an analytical framework for analyzing factors that promote customer participation in the benefit delay service and finally has proposed case study for further research.