• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.10-18
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• 2009

In order to determine the violation of right of light impact at adjacent residential area by high-rise building, analysis on the right of light for high-rise residential commercial complex building block at Gahngnam-ku, Seoul, Korea was carried out using Google Sketchup Pro. After the analysis th sunshine duration of B apartment decreased from 5 hours 16 minutes 3 hours 48 minutes by I hour 42 minutes after construction. It shows that the total sunshine duration is less than the Seoul City Government Standard which is more than 4 hours a day, or more than 2 consecutive hours. Lowering the heights of apartments by 54m would increase the total sunshine duration which would meet the Seoul City Government Standard by four hours seven minutes. Problems that rna lead to the violation on the right of light in the adjacent area should be discussed in advance and minimized by analyzing the right of light among buildings and structures which are scheduled to be constructed on the site during construction penni! process when high-rise building is proposed.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.805-808
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• 2007

Recently there are many contract claims, which are caused by duration delay, in construction industry. Many kinds of research for solving such duration delay problem are being progressed and an effective computerized system needs to improve it. This study suggests an improved methodology and necessary functions to make a time impact analysis system. This results will be useful for quantifying responsible number of days caused by duration delay.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.383-388
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• 2008

A modeling method for the impact analysis of plate structures employing Hertzian contact theory is presented in this paper. Since local deformation as well as bending deflection of the plate occurs due to the collision, it has to be considered for the impact analysis. When the coefficient of restitution is employed for the impact analysis, the local deformation is not considered. For more accurate and reliable impact analysis, however, the local deformation should be considered. The effects of the location of collision and the collision mass on the impact duration time and the contact force magnitude are investigated through numerical studies employing Hertzian contact theory.

• Journal of Construction Engineering and Project Management
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• v.4 no.4
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• pp.33-40
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• 2014

Maximizing the profitability and minimizing the duration of construction projects in extreme weather regions is a challenging objective that is essential for project success. An optimization model is presented herein for the time-profit trade-off analysis of construction projects under extreme weather conditions. The model generates optimal/near optimal schedules that maximize profit and minimize the duration of construction projects in extreme weather regions. The computations in the model are organized into: (1) a scheduling module that develops practical schedules for construction projects, (2) a profit module that computes project costs (direct, indirect, and total) and project profit, and (3) a multi-objective module that determines optimal/near optimal trade-offs between project duration and profit. One example is used to show the impact of extreme weather on construction time and profit. Another example is used to show the model's ability to generate optimal trade-offs between the time and profit of construction projects under extreme weather conditions.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.157-167
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• 2020

The purpose of this study is to analyze the relationship between the occurrence of intermediate peak and time duration, and to conduct a review for the causes of the intermediate peak. In this test, ice impact tests were conducted using a bow side shell frame and ice specimen. A total of 70 samples were manufactured. Two types of ice specimen with relatively different surface conditions were used. The criterion for dividing the two types of ice specimen was the different exposure times to room temperature after freezing. This experiment was conducted for each parameter in order to reproduce the actual icebreaking situation. As a result of the analysis, the intermediate peak in the ice load signal have been found to be caused by mechanisms by which the inner surface of broken ice contact with hull immediately after the initial hitting point of ice has been broken.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.823-835
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• 2023

Recently, due to the increase in abnormal climate, rainfall intensity is increasing and drought periods are continuing. These environmental changes lead to prolonged drought conditions and difficulties in real-time recognition. In general, drought can be judged by the amount of precipitation and the number of days without rainfall. In determining the impact of drought, it is divided into meteorological drought, agricultural drought, and hydrological drought and evaluation is made using the drought index, but environmental drought evaluation is insufficient. The river water quality managed through the total water pollution cap system is vulnerable to the effects of such drought. In this study, we aim to determine the drought impact on river water quality and quantify the impact of prolonged drought on water quality. The impact of rain-free days and accumulated precipitation on river water quality was quantitatively evaluated. The Load Duration Curve (LDC), which is used to evaluate the water quality of rivers, was used to evaluate water pollution occurring at specific times. It has been observed that when the number of consecutive rainless days exceeds 14 days, the target water quality in the mid-basin is exceeded in over 60% of cases. The cumulative rainfall is set at 28 days as the criteria, with an annual average rainfall of 3%, which is 32.1 mm or less. It has been noted that changes in water quality in rivers occur when there are 14 or more rainless days and the cumulative rainfall over 28 days is 32.1 mm or less in the Gamcheon Mid-basin. Based on the results of this study, it aims to quantify the drought impact and contribute to the development of a drought water quality index for future environmental droughts.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.4
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• pp.205-213
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• 2019

In the Pohang Earthquake in 2017, considerable damage to non-structural elements, such as ceiling systems, exterior finishes, and curtain walls, was reported; thus, the seismic designs of non-structural elements are important. In this study, the modal characteristics of a ceiling system were investigated through the impact hammer test. The frequency and damping ratio according to the length of the hanger bolt were identified. In addition, collision experiments were conducted to obtain the impact duration for exactly considering the impact effects of the ceiling against a wall or other adjacent elements. Based on the identified dynamics and impact duration of the ceiling system, the seismic responses of the ceiling system were obtained numerically in case of collision. Numerical simulation results show that the impact load tends to increase with the clearance between the ceiling and adjacent elements, and is not correlated with the length of the hanger bolt.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.2
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• pp.278-286
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• 2009

Restaurants have two strategic levers for revenue management: duration control and demand-based pricing. Reducing dining times, especially during peak periods, can add considerable revenue for restaurants. Managing meal duration, however, can be far more complex than manipulating the price. This paper examines dining duration expectations for restaurants types(Family, Korean, Quick service restaurant), customers characteristics(gender, age, occupation, meal period, visiting frequency, dining occasion, dining companions) using an a adaptation of a price sensitivity measurement tool, naming it 'Time Sensitivity measurement tool' or TSM. The TSM is then used to derive the optimal time points, and the range of acceptable times. The results demonstrate that there is a relatively wide spread of acceptable dining duration times in family restaurant. Furthermore, the optimal time points was shorter than the mean expected dining times, which suggests that many restaurants may be able to shorten dining duration without compromising customer satisfaction. The paper explores whether demographic and dining variables have an impact on time preferences, and finds whether gender, age, meal periods, visiting frequency, and dining companion effects are significant. Specifically, women in their thirties tended to prefer a significantly longer dining times for dinner.

• Korean Journal of Construction Engineering and Management
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• v.6 no.5 s.27
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• pp.69-77
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• 2005

Change is inevitable and is a reality of construction projects. Most construction contracts include change clauses and allowing contractors an equitable adjustment to the contract price and duration caused by change. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative Impact of the changes. A number of studies have attempted to quantify the impact of change orders on project costs and schedule. Many of these attempted to develop regression models to quantify the loss. However, regression analysis has shortcomings in dealing with many qualitative or noisy input data. This study develops ANN models to classify and quantify the labor productivity losses that are caused by the cumulative impact of change orders. The results skew that ANN models give significantly improved performance compared to traditional statistical models.

• Journal of KSNVE
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• v.8 no.3
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• pp.513-523
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• 1998

Impact response of a vibro-impact system and its contact mechanism was studied. The vibro-impact system is composed of a small secondary system is constrained to move along a slot of fixed length in a large primary system. The contact mechanism is characterized by its coefficient of restitution. Numerical simulation analysis has been used to determine the time-history and the impact statistics of the primary and secondary systems. Input excitation of the primary system was random, and the responses obtained were the velocities of the primary and secondary system, the closing velocity in time axis and the duration time between impacts. The validity of the numerical simulation method was checked by comparing the results with those obtained by other researchers analytically. It is shown that the results obtained by the nemerical simulation analysis showed a good agreement with those for the analytical method.