• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.260-261
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• 2017

The objective of this study is to propose the basic design plan of system by comparing and analyzing application environment of lift and elevator group control system, as preliminary study for the application of group control system to lifts for high-rise construction. The basic design plan is suggested in terms of group control algorithm, hall call system type, operation information recording device, information communication method, and operation method. The results of this study can be used as basic data for software and hardware design for application of group control technology of lifts for super tall building construction and ultimately contribute to improve the operation efficiency of lift for high-rise construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.41-45
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• 2002

Placing lift is applied to place mass concrete in order to reduce thermal cracks by hydration heat. But they results in cold joint between placing lifts, which bring about the loss of strength, water tightness and undesirable appearance. Therefore, in this paper, mechanical and hydration heat of mass concrete using super retarding agent developed through previous study are investigated in order to reduce the hydration heat and place it without place lift. According to test results, placing lifts combined with normal concrete and concrete containing super retarding agent have positive effects on reducing hydration heat. Especially, the crack index by thermal stress of the concrete containing super retarding agent less than a quarter, compared to that of plain concrete without placing lifts, and less than a half, compared to that of plain concrete with placing lifts.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.715-722
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• 2001

The main purpose of this study is to evaluate early age thermal stresses and to estimate the risk of thermal cracking in the footings of Hyungsan bridge. In this study, stress analyses are performed for several construction stages using the computation of temperature distributions. The stress analysis results show that, not using the embedded pipe cooling, placing the concrete at once for each footings may cause sever thermal cracking. So, the structures should be constructed with one horizontal construction joint. Then the height of each lifts were determined to be 1.50 meters. Using various time intervals between lifts, temperature and stress.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.205-206
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• 2011

Various studies on energy saving for construction sites have been carried out and some construction machines using motors have installed regenerative systems such as elevators and excavators. The construction lift also uses motors and generates more regenerative energy when the lifts descend because lifts convey many construction materials and workers. For this reason, it is possible to apply the regenerative system to the construction lift. However, if the system is applied without considering the lift's characteristics, the new development would fail; we therefore need to propose a performance requirement. Thus, the purpose of this study is to propose a performance requirement for the energy-regenerative lift prior to developing the energy-regenerative lift.

• Journal of the Korea Institute of Building Construction
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• v.8 no.3
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• pp.119-125
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• 2008

The volume of material and number of workers mobilized has been on the rise in line with the domestic projects getting higher, larger and complex currently. Particularly for the project in downtown, delivering the resources in timely manner is very crucial in carrying out the overall project as scheduled. Inappropriate lifting plan often causes inefficiency over the entire project, resulting in increase in schedule and cost. Despite of such importance of lifting plan for architectural work, lifting plans at the most of domestic projects, except a few cases for large scale high-rise buildings, have been heavily dependent on engineer's personal experience and intuition alone. To deal with such problems, the study was intended to develop and suggest a systematic and objective process for determining the lift, categorizing the lifting equipment into the two types, one for workers and another for material.

• Journal of the Korean Mathematical Society
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• v.61 no.5
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• pp.997-1033
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• 2024

We use Borcherds products to give a new construction of the weight 3 paramodular nonlift eigenform f_N for levels N = 61, 73, 79. We classify the congruences of f_N to Gritsenko lifts. We provide techniques that compute eigenvalues to support future modularity applications. Our method does not compute Hecke eigenvalues from Fourier coefficients but instead uses elliptic modular forms, specifically the restrictions of Gritsenko lifts and their images under the slash operator to modular curves.

• Journal of the Korean Society of Safety
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• v.8 no.2
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• pp.78-86
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• 1993

This study was aimed at analyzing the mangment system and problem situation related to the lift operation. To this end, 61 construction sites of‘H’construction Co., througnout the nation were surveyed for March 1992-May 1992.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.2079-2087
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• 2017

As the number of tall buildings is increasing, the high-speed lift is necessary in the modern world. Therefore, the further considerations for associated safety devices of lifts were required by the International Standards. In order to stop the moving of cage and keep it, the lifts have to be provided with means that can detect the unintended car movement. Therefore, the International Standard Safety Rules for the construction and installation of lifts had been revised. This paper describes the operation principles of the Rope Brake to fit the Unintended Car Movement Protection (UCMP) means required by the International Standards. This paper confirmed that the performance of these devices was suitable in the scope of the safety standards. This paper also analyzed that the shocks on working of these devices in a car would be dangerous to each passenger differently. Thus, this paper proposes a new design that the circuit diagram of the Unintended Car Movement Protection systems should be improved from the existing design to solve these internal shock problems. So, it is expected to protect passengers from the internal shocks by working of Rope Brake due to irrelevant factors.

• Korean Journal of Construction Engineering and Management
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• v.16 no.3
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• pp.68-77
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• 2015

One of recent concerns for super-tall buildings is how to manage hoisting plans and equipment efficiently. Disasters are frequently occurred in relation to electromotive hoists and cranes which are commonly used in construction sites. For construction lifts, particularly, it is highly important to conduct regular inspections or prepare against breakdown in terms of safety. However, unfortunately the reality is that regular inspections are only flatly conducted according to operating hours only. A lift, whose life span is subject to the complicated considerations such as operating hours, loading condition, and the like of each component, is far too invalid as a means of maintenance. As a way to resolve this problem and improve its convenience and safety for users, this study intends to calculate individual inspection interval for the main components of lifts by measuring their actual operating hours with sensing technology and analyzing their historical data. The findings of study include calculation of inspection intervals for the main components of lifts and classification of components to check by the actual operating hours of lift (40, 90, 130, 400 hours), which are drawn up into tables. This will make an opportunity to suggest efficient maintenance measures by enabling prevention of safety accidents and enhancement of safety for workers. Also, it will lead to increasing productivity of works by eliminating sources of delaying the term due to the breakdown of lifts.

• Journal of the Korean Professional Engineers Association
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• v.34 no.3
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• pp.64-67
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• 2001

In resent the weight of structure is heavier and bigger than before. Engineers use many heavy equipments to erect buildings and bridges. The heavy equipment is very useful to lift any weight. But most engineers do not know the impact of the weight when the equipment lifts the weight. In this study one researched into the impact of the weight in the crane work which lifts the weight in the construction site. Also along the number of pulley sheave the impact of the weight was researched. From the impact field test the impact coefficient of a single pulley sheave crane was 0.65 and the four pulley sheaves crane was 0.13. The result shows that the impact coefficient of a single pulley crane is more than 5 time of the impact coefficient of the four pulley sheaves crane and that engineers must consider the impact effect of the crane work in the construction site.