• Proceedings of the KIEE Conference
• /
• 2001.07e
• /
• pp.159-172
• /
• 2001

우리나라 전문대학은 1979년 설립당시에 비하여 괄목할 만한 양적 성장을 이루었으나 그에 비해 질적 성장과 위상의 정립은 아직 미흡한 설정이다. 산업사회에 맞추어 설계된 전문대학 교육제도는 지식기반사회에 맞는 인적자원개발 기능과 사명을 다할 수 있도록 재 설계되어야 한다. 따라서 획일화된 수업연한과 계속교 육체제의 미완성이라는 구조적 문제를 개혁해야만 하여야 할 시점이다. 수업연한은 다양한 전공과 사회의 수요에 맞추어 $2{\sim}3$년 범위안에서 다양하게 선택적으로 운영되어야 하고 단절된 학제를 연결시킬 수 있는 전공심화 과정이나 시니어보케이셔널칼리지(SVC) 제도를 도입하여 국민기본공통교육 10년 이후에 2+2(3)+2(1) +2 체제로 이어지는 순환형 직업교육체제를 구축하여야 한다.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.05a
• /
• pp.85-86
• /
• 2013

Weakness of fine powder of blast furnace slags includes the decrease of initial intensity and delay of setting time. To solve this problem, there has been research on the alkali activation to induce hardening using alkaline chemical. However, the use of chemicals is dangerous and not cost effective, which can be solved by using recycled aggregates, one of construction wastes. The role of alkali activator can be substituted by alkali of non-hydrated cement included in recycled aggregates. In this study, the alkaline value of recycled aggregates will be evaluated through the comparison of molarity of sodium hydroxide (NaOH).

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.9 no.4
• /
• pp.478-482
• /
• 2021

In this paper, methods for manufacturing shielding concrete by recycling steelmaking slag discarded as industrial waste and measuring the shielding effectiveness of the shielding concrete were studied. By comparing the result of shielding effectiveness measurement of this concrete block with shielding effectiveness measurement of the structure constructed with this concrete, the measurement system for measuring shielding effectiveness of the concrete block was verified. The size of the concrete stru ctu re is 2.9 × 2.9 × 3.4m and the concrete block is 0.3 × 0.3 × 0.2m. The frequ ency band u sed for mesu rement is 600MHz - 2GHz, the types of concrete u sed to measu re the shielding effectiveness are general concrete and concrete containing electric arc furnace oxidizing slag. In the case of the concrete structure, reinforcing rebars are installed at intervals of 15cm for stru ctu ral safety, as the frequ ency increase, the electromagnetic wave properties of rebars gradu ally decreased, there was a slight difference in the measurement results. In conclusion, the measurement result of shielding effectiveness of the concrete block is similar to the result of the concrete structure. It is thought that it can be sufficiently utilized for electromagnetic wave engineering design, and the concrete shielding effectiveness measurement system using standard specimens was verified.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.5 no.4
• /
• pp.389-394
• /
• 2017

The aim of the research is providing the application method of recycled materials to manufacture the low costed eco-friend block at currently operated concrete block plant. In this research, based on the previous research results on three types of slag cement with illite, desulfurized gypsum, and wasted refractory products, the actual block product was manufactured by the currently operated plant facility and evaluated their properties to suggest the optimal proportions. As an experimental results, in aspect of compressive strength, absorption ratio, freezing resistance, and pH, type III slag incorporating 5% desulfurized gypsum with 1% replaced illite as an aggregate could be suggested as am optimal proportion. In additionally, considering the high cost of the illite, it can be considered as an optimal proportion that type III slag incorporating 5% desulfurized gypsum for binder.

• Resources Recycling
• /
• v.26 no.3
• /
• pp.3-16
• /
• 2017

Chemical catalyst products are applied to various fields such as petrochemical process, air pollution prevention facility and automobile exhaust gas purifier. The domestic and overseas chemical catalyst market is increasing every year, and the amount of waste catalyst generated thereby is also increasing. Most of the used chemical catalyst products, such as desulfurized waste catalysts and automobile waste catalysts containing valuable metals are important recyclable resources from a substitute resource point of view. The recycling processes for recovering valuable metals have been commercialized through some urban mining companies, and SCR denitration catalysts have been recycled through some remanufacturing companies. In this paper, the amount of domestic production and recycling of major catalyst products have thus been investigated and analyzed so as to be used as basic data for establishing industrial support policy for recycling of used chemical catalyst products. Also tasks for promoting the recycling of used chemical catalyst products are suggested.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.12 no.5
• /
• pp.507-511
• /
• 2019

The use of regenerative energy in AC drive systems has been an issue since the system became an industry standard in the 1990s. According to the quantity of the regenerative energy, the braking resistor in the case of low capacity was common. However the use of such low amount of energy is actively discussed, and the method of mounting the regenerative converter is becoming popular. In this paper, an isolated regenerative converter for reducing the circulating current which is mentioned as the biggest disadvantage of the conventional power regenerative converter system is proposed. In order to save energy, employing a power regenerative converter system for utilizing regenerative energy in an AC drive system is common. However due to the structure of the system, a circulating current is generated, which inevitably causes a decrease in efficiency. In this paper, an isolated regenerative power converter system is proposed to solve the circulating current and computer simulation to verify the possibility. The simulation results show that 20% of the circulating current of the conventional system does not appear in the proposed system, and the validity of the proposed system is confirmed.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.10 no.1
• /
• pp.30-39
• /
• 2022

In this study, laboratory test, program analysis, and test construction in the field were performed to utilize Supplementary Cementitious Material (SCM) developed by recycled resources for slope reinforcement as slope improvement material for aging reservoir, and the results were analyzed. As results of the laboratory test, it was analyzed that the mixing ratio of SCM was appropriate by 9 %, and the coef. of permeability was decreased by about 10,000times, indicating a value close to that of the waterproof material applied in Korea. In addition, as a result of program analysis and test construction, it was analyzed that seepage did not occur in the part of reinforced using SCM and showed a higher safety facto r than domestic criteria. Therefore, since it shows sufficient waterproof and reinforcing effects in aging reservoir, it is judged that the slope improvement using SCM can replace the cement for repair and reinforcement method.

• Journal of Internet Computing and Services
• /
• v.24 no.2
• /
• pp.37-45
• /
• 2023

In line with the 4th Industrial Revolution, facility maintenance technologies for building smart factories are receiving attention and are being advanced. In addition, technology is being applied to smart farms and smart fisheries following smart factories. Among them, in the case of a recirculating aquaculture system, there is a motor pump that circulates water for a stable quality environment in the tank. Motor pump maintenance activities for recirculating aquaculture system are carried out based on preventive maintenance and data obtained from vibration sensor. Preventive maintenance cannot cope with abnormalities that occur before prior planning, and vibration sensors are affected by the external environment. This paper proposes an anomaly detection algorithm that utilizes ADTK, a Python open source, for motor pump anomaly detection based on data collected through current sensors that are less affected by the external environment than noise, temperature and vibration sensors.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.3
• /
• pp.94-101
• /
• 2011

In this study, in order to develop organic-inorganic hybrid packaging materials(PM) of bike paths using blast furnace slag(BS) as industrial by-products, fundamental properties of organic-inorganic hybrid packaging materials were performed. Test result, the increase of Acryl emulsion polymer(AEP)/binder(B) ratios tends to delay the setting time, to increase the table flow, to decrease the strength by material segregation and to increase the length change. The optimal mix proportion of AEP decides on 40%(AEP/B) due to workability and high strength. The increase of BS replacement ratios also tends to delay the setting time, to separate AEP from B and to decrease the strength by material segregation. When BS replacement ratios were lower than 40%, they are satisfied with goal properties.

• Journal of the Korea Institute of Building Construction
• /
• v.20 no.1
• /
• pp.27-34
• /
• 2020

In the industry, due to the carbon dioxide gas produced during cement production is increasing, research on recycling by-products has been actively conducted. In the industrial by-products, the high calcium fly ash(HCFA) produced by the blast-furnace in the circulating fluidized bed combustion method has a high ratio of CaO and CaSO4. In view of this, the purpose of this is to use high calcium fly ash(HCFA) as a stimulant in blast furnace slag powder and use it as a cement substitute. As a result, it is judged that the substitution ratio of HCFA should be 15% or less. In addition, although durability and strength are relatively lower than of OPC, it is considered that it can be utilized as an environmentally building material.