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Characteristic of Flotation for Recovery of Copper from Copper Slag in Kazakhstan (카자흐스탄 구리제련소 슬래그 내 구리회수를 위한 선별 특성)

  • Park, Jayhyun;Choi, Uikyu;Choe, Hongil;Shin, Shunghan
    • Resources Recycling
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    • v.24 no.4
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    • pp.12-21
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    • 2015
  • Almost all copper slags contain a considerable amount of Cu (0.5 - 3.7%) close to or even higher than copper ores. A number of methods for metal recovery from copper slag were reported These methods can be classified into three categories, flotation, leaching and roasting. Sulfide flotation method for the recovery of copper from Kazahstan copper furnace slag is discussed in this investigation. 50% of copper from the slag was recovered by sulfide flotation at pH 4. meanwhile 67% of copper from the slag was recovered at pH 11. Higher copper recovery result at pH 11 rather than that at pH 4 was caused by the fact that copper sulfides were floated in particle size fraction over $100{\mu}m$ in concentrates at pH 11. When the slag were ground below $74{\mu}m$by ball milling, the recovery of copper by floation in slag improved to 78 - 83% because of copper liberation effect.

Extraction of Lithium from Lepidolite through Intensive Grinding with Calcium Sulfate Hemihydrate Followed by Water Leaching (고강도 혼합분쇄 처리에 의한 인운모로부터 리튬의 수 침출 특성)

  • Kim, Byoungjin;Kim, Suyun;Lee, Jaeryeong
    • Resources Recycling
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    • v.26 no.3
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    • pp.47-52
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    • 2017
  • The concentrate of lepidolite, being treated by heavy medium separation (HMS), was ground with calcium sulphate hemihydrate (CSH, $CaSO_4{\cdot}1/2H_2O$) to investigate the mechanochemical effect for the Li leachability in water. This leachability increased, dramatically through the intensive grinding for the mixture, concentrate and CSH. The leachability of Li was improved from 4.48% to 93.5%. The grinding of the mixture destructed the crystal structure of the concentrate, and it might be formed to new compounds. As the result, Li in the concentrate can be extracted by water leaching at room temperature.

A Study on the Direction of Fisheries Finance Policy in Korea (한국수산금융정책의 방향)

  • 김경호
    • The Journal of Fisheries Business Administration
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    • v.29 no.1
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    • pp.27-63
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    • 1998
  • This paper focuses on the history of fisheries finance in Korea, especially the role of fisheries finance after the establishments of korean fisheries cooperative. We can say that our fisheries was influenced greatly by the fisheries finance. It may be preyed by the facts that our fisheries experienced a great growth right after the input of big fisheries finance. The products of fisheries has increased from 1962 to now And the structure of the fisheries has improved. But there were unequal development in the each sectors of fisheries. Though the deep sea fishery and farming has developed faster, coastal fishing that are absorbing nearly 90% of fisheries population has stagnated. Of course it was because of unequal financial assistance by Authority. So to improve fisheries evenly, it is very important to overcome various problems that have encountered including the new circumstances like the WTO. For this, lots of steps should be taken. They can be summarized as follows. 1) It may be inevitable to see a rising costs in the deep sea fishery because of the declaration of EEZ by almost every nation. 2) So coastal fishing should be getting more important. It is necessary to improve the structure of coastal fishing and we should be ready to prepare various alternatives far self-sustained growth in coastal fishing. 3) Especially fisheries finance should play more active role. 4) Self-sustainable growth means a fishery with full compatability. For full compatability it is necessary to give financial supports far making fishing ground and equipping anti-pollution system and labour saving apparatus etc. 5) Also to raise the ratio of self-support in fisheries products it is necessary to give financial support to traditional financial system. 6) Moreover it is necessary to guide utilization of finance supplied. For this the committee that is consists of professional people in that field is strongly asked. This committee should be entitled to decide and coordinate the selection of projects, allocation of finance, method of utilization and evaluation of projects etc.

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An application of wave equation analysis program to pile dynamic formulae

  • Tokhi, H.;Ren, G.;Li, J.
    • Geomechanics and Engineering
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    • v.9 no.3
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    • pp.345-360
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    • 2015
  • Wave equation analysis programs (WEAP) such as GRLWEAP and TNOWave were primarily developed for pre-driving analysis. They can also be used for post-driving measurement applications with some refinements. In the case of pre-driving analysis, the programs are used for the purpose of selecting the right equipment for a given ground condition and controlling stresses during pile driving processes. Recently, the program is increasingly used for the post-driving measurement application, where an assessment based on a variety of input parameters such as hammer, driving system and dynamic behaviour of soil is carried out. The process of this type of analysis is quite simple and it is performed by matching accurately known parameters, such as from CAPWAP analysis, to the parameters used in GRLWEAP analysis. The parameters that are refined in the typical analysis are pile stresses, hammer energy, capacity, damping and quakes. Matching of these known quantities by adjusting hammer, cushion and soil parameters in the wave equation program results in blow counts or sets and stresses for other hammer energies and capacities and cushion configuration. The result of this analysis is output on a Bearing Graph that establishes a relationship between ultimate capacity and net set per blow. A further application of this refinement method can be applied to the assessment of dynamic formulae, which are extensively used in pile capacity calculation during pile driving process. In this paper, WEAP analysis is carried out to establish the relationship between the ultimate capacities and sets using the various parameters and using this relationship to recalibrate the dynamic formula. The results of this analysis presented show that some of the shortcoming of the dynamic formula can be overcome and the results can be improved by the introduction of a correction factor.

Taekwondo Demonstrations Seen in the Perspective of Open Demonstrations: Focusing on the period from the emancipation until the 1960's (공시적 관점에서 본 태권도시범 : 광복이후부터 1960년대)

  • Na, Chae-Man;Lee, Young-Hoon
    • The Journal of the Convergence on Culture Technology
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    • v.4 no.1
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    • pp.263-273
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    • 2018
  • This study is based on literature review intended to understand how Taekwondo demonstrations have been made from the emancipation until the 1960's in the perspective of open demonstrations. The findings of this study are summed up as follows. First, Taekwondo demonstrations were influenced significantly by social situations like the emancipation and emergence of gigan studios, dispatching ROK armed forces to the Vietnam War, or the foundation of International Taekwondo Federation(ITF). Second, in terms of forms, Taekwondo demonstrations were made as a form of demonstrating martial arts that had been improved in each of the studios when there was an examination for promotion, the studio needed publicity, or they wanted to show how individuals' skills had been cultivated. In terms of contents, with basic skills of Taekwondo as the ground, they dealt with forceful hand/foot breaking, simple jumping up and breaking, sparring, and practical self-defense martial arts, and so on.

The Effectiveness of Token economy on Oral Medication for Discharged Children (토오컨 강화가 아동의 퇴원 후 투약 실천에 미치는 효과)

  • Kim Il Ok
    • Child Health Nursing Research
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    • v.6 no.1
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    • pp.69-77
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    • 2000
  • Oral medication is the most frequent treatment measure for follow up treatment, which is leading by childrens' parents for them. In medication for preoperational children, they tend to concentrate the result rather than the motivation or cause. So, they frequently refuse medication which has bitter taste. So this study was attempted to develop token economy program which promote children's medication and help their parents, and to evaluate its' effect to construct the experimental ground. This study was a quasi experimental study under the nonequivalent control group posttest only design. The subjects of this study were 36 children who were aged 3-6 years and admitted pediatric ward because of their respiratory disease. Token economy program was consisted of cartoon record paper with stickers which expresses the better medication is taken the more germs die, and gift was given for back up reinforcer. To evaluate this program, time for oral medication was measured to both experimental group and control group. To determine the effect of the program, the data were analyzed by the SAS 6.12 program with t-test. The results of this study were as follows: 1. Between experimental group and control group, there was no significant difference (t=-1.2411, P=0.2374). Therefore, the hypothesis of this study was rejected. In conclusion, the token economy program for follow up care didn't change the children's behavior of oral medication. But it was found that the cartoon on recording paper gave a pleasure to participated children. Parents who were in experimental group expressed their appreciation for token economy program. So it can be said that the token economy program for follow up care was effective in inducing the children's pleasure and parents' satisfaction even though it wasn't successful in experiment. If the measuring tools for token economy program was made with well planned design and high reliability, it can be improved the effectiveness of that To develope the theoretical bases of nursing care, the well planned programs and measuring tools for them should be developed.

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A Pilot Study of In-hole Seismic Method (인홀탄성파시험의 타당성 연구)

  • Mok, Young-Jin;Kim, Jung-Han;Kang, Byung-Soo
    • Journal of the Korean Geotechnical Society
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    • v.19 no.3
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    • pp.23-31
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    • 2003
  • Over the past half century, borehole seismic surveys have been diversified into the three techniques such as crosshole, downhole, and suspension logging according to their devices and testing configurations. These field techniques have been improved, in terms of equipment and testing procedures, and are very valuable in the evaluation of ground characteristics for geotechnical and earthquake engineering problems. Yet, despite the importance and significance of the techniques as engineering tools, the techniques are not much used as standard penetration test (SPT) by practicing engineers. The possible explanations are cost and operational difficulties of the surveys as well as sophistication and complexity of the devices. An in-hole seismic method has been developed to meet the requirement of economical testing cost and practicality in engineering practice to measure dynamic soil properties. The prototype in-hole probe developed herein is small and light enough to be fit in three-inch boreholes and to be handled with bare hands. The performance of the source has been evaluated through extensive crosshole tests at various sites. The in-hole seismic method was adopted at three test sites and verified by comparing with crosshole results.

Development of a Rule-based BIM Tool Supporting Free-form Building Integrated Photovoltaic Design (비정형 건물일체형 태양광 발전 시스템 규칙기반 BIM설계 지원 도구 개발)

  • Hong, Sung-Moon;Kim, Dae-Sung;Kim, Min-Cheol;Kim, Ju-Hyung
    • Journal of KIBIM
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    • v.5 no.4
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    • pp.53-62
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    • 2015
  • Korea has been at the forefront of green growth initiatives. In 2008, the government declared the new vision toward 'low-carbon society and green growth'. The government subsidies and Feed-in Tariff (FIT) increased domestic usage of solar power by supplying photovoltaic housing and photovoltaic generation systems. Since 2000, solar power industry has been the world's fastest growing source with the annual growth rate of 52.5%. Especially, BIPV(Building Integrated Photovoltaic) systems are capturing a growing portion of the renewable energy market due to several reasons. BIPV consists of photovoltaic cells and modules integrated into the building envelope such as a roof or facades. By avoiding the cost of conventional materials, the incremental cost of photovoltaics is reduced and its life-cycle cost is improved. When it comes to atypical building, numerous problems occur because PV modules are flat, stationary, and have its orientation determined by building surface. However, previous studies mainly focused on improving installations of solar PV technologies on ground and rooftop photovoltaic array and developing prediction model to estimate the amount of produced electricity. Consequently, this paper discusses the problem during a planning and design stage of BIPV systems and suggests the method to select optimal design of the systems by applying the national strategy and economic policies. Furthermore, the paper aims to develop BIM tool based on the engineering knowledge from experts in order for non-specialists to design photovoltaic generation systems easily.

Integrating GPS/INS/PL for Robust Positioning: The Challenging Issues

  • Wang, Jinling;Babu, Ravindra;Li, Di;Chan, Franics;Choi, Jin-Ho
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.127-132
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    • 2006
  • The Global Positioning System (GPS), Inertial Navigation System (INS) and Pseudolite (PL) technologies all play very important roles in navigation systems. As an independent navigation system, GPS can provide high precision positioning results which are independent of time. However, the performance will become unreliable when the system experiences high dynamics, or when the receiver is exposed to jamming or RF interference. In comparison to GPS, though INS is autonomous and provides good short-term accuracy, its use as a standalone navigation system is limited due to the time-dependent growth of the inertial sensor errors. PLs are ground-based transmitters that can transmit GPS-like signals. They have some advantages in that their positions can be determined precisely, and the Signal-to-Noise Ratios (SNR) are relatively high. Because their combined performance, in principle, overcomes the shortcomings of the individual systems, the integration of GPS, INS and PL is increasingly receiving attention from researchers. Depending on the desired performance vs complexity, system integration can be carried out at different levels, namely loose, tight and ultra-tight coupling. Compared with loose and tight integration, although it is more complex in terms of system design, ultra-tight integration will be the basis of the next generation of reliable and robust navigation systems. Its main advantages include improved performance under exposure to high dynamics, and jamming and RF interference mitigation. This paper presents an overview of the ultra-tight integration developments and discusses some of the challenging issues.

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Adaptive weight approach for stereo matching (적응적 가중치를 이용한 스테레오 정합 기법)

  • Yoon, Hee-Joo;Hwang, Young-Chul;Cha, Eui-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.08a
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    • pp.73-76
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    • 2008
  • We present a area-based method for stereo matching using varying weights. A central problem in a area-based stereo matching is different result from selecting a window size. Most of the previous window-based methods iteratively update windows. However, the iterative methods very sensitive the initial disparity estimation and are computationally expensive. To resolve this problem, we proposed a new function to assign weights to pixels using features. To begin with, we extract features in a given stereo images based on edge. We adjust the weights of the pixels in a given window based on correlation of the stereo images. Then, we match pixels in a given window between the reference and target images of a stereo pair. The proposed method is compared to existing matching strategies using both synthetic and real images. The experimental results show the improved accuracy of the proposed method.

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