• Journal of Technology Innovation
• /
• v.22 no.1
• /
• pp.1-22
• /
• 2014

R&D investment also has a gestation period similar to other investments in economics. The gestation period originates from time lag effect of input and output. Thus it is necessary to consider time lag effects when analyzing the relationship between firms' R&D investment and R&D performance. The main objective of this research is to estimate the length of time lag effect of R&D investment. The Almon distribution lag model was applied to estimate the time lag effect. The firm level panel dataset was established from 2002 to 2009. The net value of R&D investment and the number of patent applications were used to measure R&D input and output, respectively. This method found the estimated time lag to be 1~2 years across all datasets. The same analyses were applied to chemical, metal, electronic, exact science, and machinery industries' data. And we found there were differences among sectors in regard to the time lag effect.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.1
• /
• pp.87-92
• /
• 2012

This study examines the relationship between R&D investment and subsequent outputs of the research activity. Usually, there is some time difference between the production of research outputs, such as academic papers and application or registration of patents, and the investment of R&D expenditure. The time lag for producing this kind of research outputs should be considered to evaluate the performance of research activity exactly. The purpose of this study is to identify time lag effect between the times of input and output of a R&D activity and to derive the degree of time lag using the data set of a long term R&D program supported by Korean government. A modified Almon model is suggested to identify the time lag effect between input and output of research activities performed by this program. Time-series cross-section data from 16 research centers between 2001 and 2009 are used to find time lag effect.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.3
• /
• pp.8-14
• /
• 2019

Most of the data envelopment analysis (DEA) models evaluate the relative efficiency of a decision making unit (DMU) based on the assumption that inputs in a specific period are consumed to produce the output in the same period of time. However, there may be some time lag between the consumption of input resources and the production of outputs. A few models to handle the concept of the time lag effect have been proposed. This paper suggests a new multi-period input DEA model considering the consistent time lag effects. Consistency of time lag effect means that the time delay for the same input factor or output factor are consistent throughout the periods. It is more realistic than the time lag effect for the same output or input factor can vary over the periods. The suggested model is an output-oriented model in order to adopt the consistent time lag effect. We analyze the results of the suggested model and the existing multi period input model with a sample data set from a long-term national research and development program in Korea. We show that the suggested model may have the better discrimination power than existing model while the ranking of DMUs is not different by two nonparametric tests.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.37 no.4
• /
• pp.37-50
• /
• 2012

The existing DEA models have been devoted to evaluate relative efficiency of DMUs based on multiple input and output factors of a same period. However, a certain kind of lead time can be required to produce outputs using inputs in an organization. R&D evaluation is a typical area with this kinds of time lag. Thus, the purpose of this paper is to develop a new DEA model to deal with time lag effect in performance evaluation. The proposed model is to find relative efficiency of each DMU for each period considering the time lag effect. A case example using a real data set is also given to show the usage or implication of the suggested model. The results are compared with the ones of the CCR model and the multi-periods input model.

• Journal of Information Technology Applications and Management
• /
• v.16 no.4
• /
• pp.205-222
• /
• 2009

Considering time-lag in the performance evaluation of information system (IS) investment is important because its effect reveals after certain period of time passed. Particularly it is more in the systems of e-government informatization projects which the amount of investment and the scale of business are huge. Many methods to solve this issue have been proposed such as system dynamics methods, simulations, structural equations etc. However, it is still difficult and unsolved problem because collecting practical data for time-lag analysis is very hard. In this paper, we analyze IS time-lag effect through factor analysis using the accumulated practical operational DB data. For the performance evaluation of the G4C system, the representative e-government web portal, we selected eleven factors reflecting time passing in G4C DB data. With these factors this paper conduct time-lag analysis in four view points. First, we conducted 'Stabilizing of G4C system' and got a result that IS is needed about three years for the stabilization. Second, we conducted 'Utilization of G4C system' and got a result that the utilization reaches appropriate level after in three years later after the introduction of G4C system. Third, we conducted 'Cost reduction effect' and got a result that cost reduction is stable in the third year after the introduction of G4C system. Lastly, we conducted 'System maturity effect' and got a result that the system reaches to the quality level that users expect after third to fourth years. According to the results of this research, we found that performance of IS improv continuously not immediately, and it needs three or four years of time-lag.

• Journal of the Korean Geotechnical Society
• /
• v.20 no.6
• /
• pp.109-118
• /
• 2004

The consolidation of clay occurs with time lag, and this kind of lag can be separated into plastic lag and hydraulic lag. In this study, CRS tests were performed to research the effect of original secondary consolidation of the clay with respect to the characteristics of consolidation. Test results showed that plastic time lag was one of the key factors to get the preconsolidation pressure, and suggested the formula of the Quasi-preconsolidation pressure obtained from the relationship between consolidation time lag and consolidation pressures. In addition though the characteristics of coefficient of consolidation show a wide range of values, after passing the double preconsolidation point, it showed the tendency to converge into the constant value. The coefficient of permeability in normally consolidated state is related to its void ratio, and the permeability variables, n and $C_1$ were determined by the test results using the equation suggested by Samarasinghe. et. al. And then the equation was compared with the Kozeny-Carman's equation. Because of delayed compression caused by consolidation time lag, aging effect could be also found in the relationship between coefficient of permeability and void ratio.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2156-2159
• /
• 2005

ADS(Address Display Period Separation) driving method has been considered to be the most appropriate driving technique for AC PDP. ADS driving method is composed of reset, address, sustain and erase period. Therefore, a long time should be allocated to an address period, which results in a reduction of brightness. To realize a high luminance and high picture quality, it is necessary to high speed addressing. However, address discharge time lag increases as the temperature decreases, which can cause the misfiring and low picture quality In this paper, the electric field effect and priming particle effect are investigated in order to reduce the address discharge time lag at low temperature. Address discharge time lag was reduced effectively when the priming particles are provided.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1181-1184
• /
• 2007

The new self-priming addressing driving scheme was proposed to improve an address discharge time lag. It utilizes the priming effect maintaining the priming ramp discharge during an address period and the address discharge time lag is significantly improved. In this study, the basic characteristics of the priming ramp discharge are presented.

• Journal of Digital Convergence
• /
• v.10 no.8
• /
• pp.341-346
• /
• 2012

This paper reports the findings of research into the effect of flow experience and internet addiction on e-learning participation. The total number of access, playing time of contents and lag time (time between content upload and first access) were investigated as e-learning participation by analyzing web log data. The paper also examines the relationship between academic achievement and e-learning participation. The results suggest that the flow experience significantly correlates with all variables related with e-learning participation and internet addiction significantly correlates with lag time. It is found that female students significantly access more, longer and have shorter lag time than their male counterparts. It also suggest total number of access, lag time and gender difference have significant effect on academic achievement.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.8 no.1
• /
• pp.67-81
• /
• 2000

An experimental study was performed on the time lag, lift and drag characteristics of a multi functional spoiler which is a device to increase lift and drag contrary to conventional spoiler which decrease lift and increase drag. In this study, a wind tunnel investigation was made of the effect of incidence angle, slot width, and chordwise location of multi functional spoiler on the time lag, lift and drag characteristics of a wing. The results indicate that the time lag of a multi functional spoiler is influenced mainly not only by the chordwise location of a spoiler but also by the slot width between spoiler and wing upper surface. Multi functional spoiler can reduce time lag effectively by slotting the trailing edge of spoiler with slot ratio (slot width devided by the wing chord length) between 0.05 and 0.1. Also, it shows that the lift and drag coefficients of the wing with the multi functional spoiler and trailing edge flap are increased by 20% and 80%, respectively, compared to the wing with trailing edge flap only.