• KSBB Journal
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• v.22 no.5
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• pp.271-277
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• 2007

Natural pigments have many applications like colouring agent, pigments, food additives, and antiseptics. At present, instead of synthetic pigments that have contributed to the development of industry, many kinds of natural pigments have been developed. The constituents of gardenia fruits, Gardenia jasminoides ELLIS, are traditionally known as herb medicine and natural dyes/pigments due to the customer is needs. The fruits produce yellow carotenoid pigments and iridoid compounds. The two main components in the yellow pigments are called crocin and crocetin. The extraction mode of yellow pigment from Gardenia is depended upon the extraction time, temperature, and volume of solvent. Red pigments or blue pigments formed from geniposide and amino acids have been reported a lot. Geniposide, the principal iridoid glucoside contained in gardenia fruit, was hydrolyzed to genipinic acid or genipin as a precursor for the pigment by enzymatic or chemical reaction. These red or blue pigments prepared with materials hydrolyzed of geniposide and amino acid and had properties governed by the electrostatic character of the amino acid. The pigments showed good stability to heat and pH but were gradually bleached by light while the other natural pigments are unstable in light, heat, acid, and base solution. The safety of the pigments was considered to be of little virulences in comparison to synthetic pigments.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.415-423
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• 2006

As the shortage of natural & good quality aggregate for concrete, it is needed development of alternative aggregate. At the present time, the crushed sand is widely used among the alternation aggregate, and the usage of crushed sand will be increased more and more. Generally, crushed sud is produced with wet process in domestic, but some manufacturing companies which are handicapped with local restrict are produced by dry process. In this study, analyzing the facilities of dry crushed sand, the quality properties of dry crushed sand was done by Korean Industrial Standards. Based on the quality results of dry crushed sand, the experiment of concrete with the dry crushed sand which is substitute for sea sand was done. As the results of basic qualities, the amount of 0.08 mm sieve passing ratio was over KS criteria, and the fineness modulus was higher than sea sand, and the other physical properties of dry crushed sand was similar to sea sand. The results of concrete experiment, according to the substitutive ratio of dry crushed sand is increased, the slump and air content of concrete was decreased by increase of fine particles of dry crushed sand, and the unit weight content, compressive & tensile strength of concrete were increased on the contrary. The physical properties of concrete used dry crushed sand were showed same tendency without relation to W/B. Consequently, if the fine particle contents of dry crushed sand was lower, it is judged that dry crushed sand is no problem to use for concrete aggregate and the amount of usage will be increased.

• Journal of the Korea Concrete Institute
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• v.27 no.1
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• pp.65-73
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• 2015

This study discussed the pozzolanic properties of calcined sewage sludge (CSS) according to calcination and fineness conditions. The chemical and mineralogical analysis of CSS according to calcination temperature and time were carried out and compared with that of the existing pozzolanic materials such as fly-ash, blast furnance slag and meta-kaolin. Various mortars were made by mixing those CSS and $Ca(OH)_2$ (1:1 wt. %), and their compressive strength and hydrates according to experimental factors such as fineness of CSS and curing age were also investigated in detail. The results show clearly the potentiality of calcined sewage sludge (CSS) as an admixture materials in concrete, but the CSS should be controlled by calcination temperature and time, and fineness etc. In this experimental condition, the calcination temperature of $800^{\circ}C$, calcination time of 2 hours and fineness of $5,000cm^2/g$ were optimum conditions in consideration of the mechanical properties and economic efficiency of CSS. The compressive strength of CSS mortars was higher than that of fly-ash mortars and blast furnace slag mortars, especially at the early ages. Then, the utilization of CSS in construction fields was greatly expected.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.12
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• pp.78-89
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• 1999

Previous wavelet network structures are determined by considering the relationship between wavelet windows distribution of training patterns that are transformed into time-frequency space. Because it is separated two algorithms that determines wavelet network structure and that modifies parameters of network, learning process that minimizes output error of network is executed after the network structure is determined. But this method has some weakness that training patterns must be transformed into time-frequency space by additional preprocessing and the network structure should be fixed during learning process. In this paper, we propose a new constructing method for wavelet network structure by using differences between the output and the desired response without preprocessing. Because the algorithm perform network construction and error minimizing process simultaneously, it can determine the number of hidden nodes adaptively as with the complexity of problems. In addition, the network structure is optimized by inserting new hidden nodes in the area that has maximum error and extracting hidden nodes that has no effect to the output of network. This algorithm has no constraint condition that all training patterns must be known, because it removes preprocessing procedure for training patterns and it can be applied effectively to systems that has time varying outputs.

• 한국벤처창업학회:학술대회논문집
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• 2018.04a
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• pp.177-180
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• 2018

최근 4차 산업혁명 시대라 하여 새로운 기술들이 등장하고 기술들이 융합되면서 새롭고 혁신적인 산업과 서비스가 창출되고 있다. 이러한 시대에 청소년들의 새로운 아이디어와 기술은 4차 산업혁명에 맞는 새로운 성장 동력을 확보할 수 있을 것이라고 여겨진다. 4차 산업의 혁명이 요청되는 이 시기에 산업을 견인할 수 있는 길은 창업의 길이다. 따라서 창업을 통해 4차 산업혁명을 이끌어갈 수 있는 인재가 무엇보다도 필요하다. 청소년들은 학교 프로그램을 통해 다양한 창업교육을 접하고 있으며, 공공기관의 대표적인 창업교육은 중소벤처기업부(구 중소기업청)가 주관하고 있는 BizCool이 있다. 교육부에서 중학생들에게 자유학기제를 2016년 1월 1일부터 실시하고 있으며 BizCool 교육을 통한 창업, 진학, 취업의 우수 사례들이 등장하면서 2017년 현재 대한민국 약 500여개의 학교에서 중소벤처기업부의 지원을 받아 BizCool 교육이 진행 되고 있다. BizCool은 청소년들의 기업가정신 함양 및 모의 창업 교육을 통해 확고한 경제관념을 형성하고 꿈 끼 도전정신 진취성을 갖춘 '융합형 창의인재' 양성을 목적으로 한다. 본 논문은 중학교 자유학기제를 통한 창업교육이 학생들에게 긍정적 사고와 학습성취도에 미치는 관계에 대해 연구하는데 목적을 두었다. 이 목적을 달성하기 위하여 대전광역시교육청에서 자유학기제 BizCool 교육을 받는 3개 학교를 선정하였고 갑천중, 도안중, 문정중 3개 학교의 창업교육 담당교사의 도움을 받아 창업교육 참가 학생을 대상으로 설문조사를 실시하여 연구결과를 분석하였다. 실증분석결과, 첫째, 창업교육은 학생들의 긍정적 사고에 양의 영향을 미친다는 것을 확인하였다. 둘째, 창업교육은 학생들의 학습성취도에 양의 영향을 미친다는 것을 제시하였다. 셋째, 창업교육은 학생들의 학습성취도에 긍정적 사고가 매개효과를 미친다는 것을 분석하였다. 본 연구에서 시사하는 바는 다음과 같다. 첫째, 연구결과 자유학기제 창업교육은 학생들에게 학습성취도를 높여 주었다. 따라서 학생들에게 도움이 되는 BizCool 교육을 전국 초, 중, 고등학교 11,733개교에 확산시켜 체계적으로 습득 할 수 있는 환경이 조성되어야 할 것이다. 둘째, 연구결과 창업교육은 긍정적 사고에 영향을 미쳤다. 전기숙(2016)에 따르면 청소년의 행복에 있어서 긍정적인 대인관계가 가장 중요한 요인이 된다고 하였다. BizCool 교육을 통해 사람과 팀의 소중함을 깨달으며 소통하는 법을 노력한다면 바른 인성을 갖춘 창의성 높은 학생들로 성장할 것이다. 셋째, 연구결과 창업교육의 학습성취도는 긍정적 사고를 가지고 있는 학생들에게 더욱 높게 나타났다. 긍정적 사고를 가지고 자신감 있게 매사 행동해 나간다면 학생들은 성취로 인한 만족감을 느끼며 행복한 학교생활을 해나갈 수 있고 BizCool 교육과 함께 멋진 미래를 만들어 갈 것이다. 본 연구에서 한계점은 다음과 같다. 첫째, 특정 지역, 특정 학교를 대상으로 실시하였기 때문에 표본의 수가 제한적이므로 전체를 대표하기에는 제약이 있다. 둘째, 긍정적 사고는 학생들의 환경과 상황에 따라 달라질 수 있으므로 연구 대상자의 조건 면에서 한계가 있다. 셋째, 중학교 자유학기제 창업교육의 체계화가 미비하다. 학교에서 창업교육을 하는 담당 교사는 창업 경험이 풍부하지 않기 때문에 창업교육 전문가가 필요하며 국가기관과 기업 등이 연계한 학습 형태를 구축하여 더 활발하고 현장감 있는 창업교육이 실시되기를 바란다.

• Atmosphere
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• v.24 no.1
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• pp.123-130
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• 2014

The automated prediction system for seasonal tropical cyclone (TC) activity is established at the National Typhoon Center of the Korea Meteorological Administration (KMA) to provide effective operation and control of the system for user who lacks knowledge of the system. For automation of the system, two procedures which include subjective decisions by user are performed in advance, and their output data are provided as input data. To provide the capability to understand the operational processes for operational user, the input and output data are summarized with each process, and the directory structure is reconstructed following KMA's standard. We introduce a user interface using namelist input parameters to effectively control operational conditions which is fixed or should be manually set in the previous version of the prediction system. To operationally use early prediction which become available through the automation, its performances are evaluated according to initial condition dates. As a result, high correlations between the observed and predicted TC counts are kept for all track clusters even though advancing the initial condition date from May to January.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.29-45
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• 2017

Ad hoc sensor network is characterized by decentralized structure and ad hoc deployment. Sensor networks have all basic features of ad hoc network except different degrees such as lower mobility and more stringent energy requirements. Existing protocols provide different tradeoffs among some desirable characteristics such as fault tolerance, distributed computation, robustness, scalability and reliability. wireless protocols suggested so far are very limited, generally focusing on communication to a single base station or on aggregating sensor data. The main reason having such restrictions is due to maximum lifetime to maintain network activities. The network lifetime is an important design metric in ad hoc networks. Since every node does a router role, it is not possible for other nodes to communicate with each other if some nodes do not work due to energy lack. In this paper, we suggest an experimental ad-hoc on-demand distance vector routing protocol to optimize the communication of energy of the network nodes.The load distribution avoids the choice of exhausted nodes at the route selection phase, thus balances the use of energy among nodes and maximizing the network lifetime. In transmission control phase, there is a balance between the choice of a high transmission power that lead to increase in the range of signal transmission thus reducing the number of hops and lower power levels that reduces the interference on the expense of network connectivity.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.6
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• pp.49-57
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• 2003

Although there are several experimental techniques to evaluate the seismic behavior and performance of civil structures, small-scale models in mast of physical tests, instead of prototypes or large-scale models, would be used due to a limitation on capacities of testing equipments. However, the inelastic seismic response prediction of small-scale models has some discrepancies inherently because the similitude law is generally derived in the elastic range. Thus, a special attention is required to regard the seismic behavior of small-scale models as one of prototypes. In this paper, differences between prototypes and small-scale models pseudodynamically tested on steel column specimens are investigated and an alternative to minimize them is suggested. In general, small-scale models could have the distorted stiffness induced from some experimental errors on test setup, steel fabrication and so on. Therefore, a modified similitude law considering both a scale factor for length and a stiffness ratio of small-scale model to prototype is proposed. Using the modified similitude law to compensate experimental errors, the pseudodynamic test results from modified small-scale model are much improved as compared with the results of prototype. According to the pseudodynamic test results of small-scale steel models, it can be concluded that the modified similitude law proposed could be effective in simulating the seismic response of prototype structures.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.171-180
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• 2020

With the increase in industrialization and urbanization, scarcity of space for leisure life has become an important issue. Opportunities such as natural scenery and ecological experiences provided by waterfront spaces around streams are fundamental factors in the development of the community and creation of a hydrophilic park. In the past, on-site surveys have been conducted using human resources to quantify the number of river visitors, but the accuracy of the results was not sufficient owing to limitations in expenses, manpower, space, and time. In this study, to overcome this problem, we estimated the number of visitors using the location information related to hydrophilic parks. The study areas were Samrak Ecological Park and Daejeo Ecological Park located downstream of the Nakdong River. We compared and analyzed the pattern of the visitors by using the large communication data and the visiting pattern based on GPS location information. The GPS location information is based on Google Popular Times and Kakao visitor data. When the GPS location data were used, the pattern for weekday and weekend visitors was clearer than when the large communication data were used. Therefore, it is expected to be similar to the result of GPS location information if the number of visitors is extracted under the condition of precision of pCELL size and residence time of 30 minutes or more when using future communication big data. In addition, if revisions such as the Personal Information Protection Act are made to extract more accurate data, by estimating the number of visitors based on GPS data, more accurate indicators of the number of visitors can be derived.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.131-137
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• 2004

Conventional traffic signal optimization models assume that green intervals for pedestrian crossings are given as exogenous inputs such as minimum green intervals for straight-ahead movements. As the result, in reality, the green intervals of traffic movements may not distribute adequately by the volume/saturation-flow of them. In this paper, we proposed signal optimization models formulated in BMILP to integrate pedestrian crossings into traffic movements under under-saturated traffic flow. The model simultaneously optimizes traffic and pedestrian movements to minimize weighted queues of primary queues during red interval and secondary queues during queue clearance time. A set of linear objective function and constraints set up to ensure the conditions with respect to pedestrian and traffic maneuvers. Numerical examples are given by pedestrian green intervals and the number of pedestrian crossings located at an arm. Optimization results illustrated that pedestrian green intervals using proposed models are greater than those using TRANSYT-7F, but opposite in the ratios of pedestrian green intervals to the cycle lengths. The simulation results show that proposed models are superior to TRANSYT-7F in reducing delay, where the longer the pedestrian green interval the greater the effect.