• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.2
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• pp.95-112
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• 1998

For the effective disposal of organic food wastes, we seleted 4 strains of microorganism from 186 microbial candidate via enzyme activity test, salt tolerance, food decomposition rate, stability and safety of strains. The identity of these 4 strains are as follows : Fungi is Rhizopus sp., yeasts are Galactomyces sp., Pichia sp. and Hyphopichia sp., In the 50L fermenter scale, we tested various fermenting factor for the optimization of conditions of food waste decomposition using 4 selected strains. The optimum fomenting conditions were as follows : BIO-CHIP Volume 25-30 L, BIO CHIP size 2.0-6.0mm, air flow 200-280L/min, mixing intensity 2-4rpm, temperature $30-45^{\circ}C$. In these fermenting conditions, the efficiency of decomposition(rate of weight loss of food wastes) were 93%. Also the quality of fermenting output were assayed at the basis of fertilizer, and the results were as good as general compost.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.81-89
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• 2004

The vibration analysis of the circular arch as a member of a structure has been an important subject of mechanics due to its various applications to many industrial fields. In particular, circular arches with variable cross section are widely used to optimize the distribution of weight and strength and to satisfy special architectural and functional requirements. The Generalized Differential Quadrature Method (GDQM) and Differential Transformation Method (DTM) were recently proposed by Shu and Zou, respectively. In this study, GDQM and DTM were applied to the vibration analysis of circular arches with variable cross section. The governing equations of motion for circular arches with variable cross section were derived. The concepts of Differential Transformation and Generalized Differential Quadrature were briefly introduced. The non-dimensionless natural frequencies of circular arches with variable cross section were obtained for various boundary conditions. The results obtained using these methods were compared with those of previous works. GDQM and DTM showed fast convergence, accuracy, efficiency, and validity in solving the vibration problem of circular arches with variable cross section.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.165-172
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• 2015

The extreme weather conditions become frequent and severe with global warming. To prevent and cope forest disaster like a forest fire, we need an accurate micrometeorological prediction system for mountainous regions. This study addressed the forest fires occurred at Bonghwa and Gangneung in March, 2013. We constructed and optimized the prediction system that were required to interpret and simulate the forest micrometeorology. At first, we examined WRF physical sensitivity. Subsequently, KMA AWS observation data were assimilated using three-dimensional variation data assimilation method. The effectiveness of the assimilation was examined by using AWS observations enhanced with the Forest Research Institute observations. Finally, The 100 meters spatial resolution wind data were obtained by using the MUKLIMO for the given wind vector from WRF.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.1
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• pp.28-34
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• 2010

The pulse width modulation(PWM) method has been generally used as conventional method controlling luminance of LED(light emitting diode). PWM method as analog method with a relation that duty ratio of LED be proportional to luminance has weak point that it is not compatible with digital method of communication etc. In this paper, a experiment is conducted which the luminance of RGB LED be controlled by digital method. For this, the LED digital control system is developed which consist of LED driving circuits and digital logic circuits. By controlling the number of pluses on RGB LED versus digital input, various lighting colors is implemented and digital codes are optimized in order that measured x, y chromaticity coordinates of lighting colors are comprised in the CIE chromaticity coordinates area of targeted lighting colors. The result of this study can be utilized usefully in research on implementing full color by using remote control of LED lamp with digital communication.

• Journal of KIISE:Information Networking
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• v.37 no.2
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• pp.85-93
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• 2010

WLAN virtualization can make multiple simultaneous experiments, each of which is conducted by a separate researcher, share scarce wireless resources in an IEEE 802.11 WLAN. The experiment performed in a virtualized WLAN should be consistent with that in a non-virtualized WLAN. The more similar these two experimental results, the better the consistency. To this end, we propose a novel virtualization scheme that has good consistency by preventing multiple simultaneous experiments from interacting with one another, without any modifications to the IEEE 802.11 standard. Through an intensive simulation study, we confirm that the consistency depends not only on the number of simultaneous experiments but also on wireless channel characteristics such as Doppler frequency and Ricean factor. According to such dependencies, the proposed scheme is optimized, so that it supports good consistency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.3
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• pp.443-450
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• 2020

No established method can be used to select effective antibiotics in antibiotic susceptibility tests for fish bacterial pathogens quickly and accurately. Here, we established the optimal conditions for determining the minimal inhibitory concentration (MIC) of major fish bacterial pathogens (Streptococcus spp., Edwardsiella tarda, Vibrio spp., Aeromonas spp., and Pseudomonas spp.) using the KRAQ1 and CAMPY2 panels. The MIC panel used 18 antibiotics of two types and we conducted experiments to establish the optimal culture medium and temperature for each species. The optimal conditions for incubating Streptococcus spp. were in cation-adjusted Mueller-Hinton broth with TES buffer (CAMHBT) at 28℃, using 5% lysed horse blood (LHB) as recommended by the Clinical Laboratory Standards Institute. For Vibrio spp., the optimal culture conditions were 28℃ in CAMHBT supplemented with 1% NaCl. The optimal conditions for culturing E. tarda, Aeromonas spp., and Pseudomonas spp. were in CAMHBT at 28℃.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.122-124
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• 2005

Underground distribution system is a trend due to the successive development of metropolitan area and satellite cities and the environment of the commercial and residential areas. The high quality of electricity, which is related with the minimal outage duration time due to the maintenance work for the underground distribution line, is mandatory. Hence, the construction method and tools for the outage-free maintenance construction have been required for underground distribution system. So far, all the efforts for outage-free maintenance for the underground distribution have been limited only to the survey for foreign countries situation and the theoretical provision; thus, It is required to develop the various construction method and the application tools. Differently from the aerial line, the construction of the underground cable is complicated and the insulation distance between conductor and shield should be maintained in loadmaking/breaking operation, though the apparatus connected with cable is a deadfront type. Also since the apparatus is installed above ground, by-pass of faulted area at busy area needs a variety of high technologies. Therefore, in this these, the authors introduce the development status of the loadbreak connectors, connection facilities, outage-free maintenance system for secondary side, a secondary auxiliary bushing and additional tools so that there can be more progress on this field.

• Polymer(Korea)
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• v.27 no.2
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• pp.142-151
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• 2003

PMMA panels are made by two fabrication methods; cell molding and belt molding processes. But these methods have disadvantages in productivity and cost. So plastic processing engineers are very interested in developing a new production method for PMU panels using plastic films as molds because the new method can reduce production cost of belt molding method as well as can improve productivity of cell molding method. To give a solution for developing such a new molding method, the effects of melthyl methacrylate compound composition and curing reaction condition on the processability and mechanical strength of PMMA panels were investigated in this study. Poly(vinyl acetate) film was used as molds in producing PMMA panels. To determine an MMA compound showing good processability and good mechanical properties after curing, ingredients and their compositions were optimized step by step. Acrylic acid, as a coupling agent and a modifier, played an important role in increasing mechanical strength of PMMA panels.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.381-388
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• 2016

Biopolishing using cellulases was introduced in the production of cotton fabric in order to improve the quality of fabric environmental friendly and is commonly used in the textile industry. In this study, the application of a crude cellulase from Acanthophysium sp. KMF001, which was excellent for the saccharification of cellulose, on biopolishing was evaluated. The optimum treatment biopolishing condition was at $50^{\circ}C$ and pH 4.5 for 60 minutes with 10% crude cellulase of fabric weight. After the optimized biopolishing, the crude cellulase of Acanthophysium sp. KMF001 reduced the tensile strength of the tested cotton fabric less than a commercial cellulase. The appearance of the cotton fabric after the treatment of the crude cellulase of Acanthophysium sp. KMF001 was similar to the fabric after a commercial cellulase treatment. All these results support that the crude cellulase of Acanthophysium sp. KMF001 was a good biopolishing cellulase.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.05a
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• pp.15-16
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• 2002

라이너지는 대부분의 원료물질을 고지로부터 얻고 있는 친환경적 상품이 다. 그러나 고지를 원료로 사용함에 따라 많은 문제가 발생하게 된다. 그중 원료와 함께 유입되는 다양한 종류의 오염물질로 인하여 기인되는 스틱키는 강도를 저하시킬 뿐 아니라 얼룩 및 반점을 형성하여 제품의 질을 떨어뜨리 고, 또한 설비를 오염시켜 수명 단축 및 세척에 의한 조업중단 등 생산성 저 하를 가져온다. 이러한 문제는 초지기의 대형화와 고속화, 용수조건의 악화 및 고지 재활용율 증가 등의 이유로 더욱 커지고 있다. 본 논문에서는 라이너지 생산공정의 가운데 지료조성공정의 매크로 스틱 키 정량분석을 통하여 전반적인 분포를 조사하였다. 그 결과 매크로 스틱키 는 스크린과 클리너를 통해 다량 제거되고, 공정상의 기계적 에너지에 의해 더욱 미분화되어 제어가 어려운 마이크로 스틱키로 진행되고 있음을 확인하 였다. 또 지료 분급을 위하여 설치된 플로테이션 설비는 기존의 정선설비인 스크린과 클리너에서 제거되기 어려운 마이크로 스틱키를 제거할 수 있음을 확인하였다. 본 연구에서는 실제 공정의 마이크로 스틱키 정량이 가능한 설비를 제작 하였다. 제작된 설비는 마이크로 스틱키의 정량 뿐만 아니라 환경의 변화에 따른 마이크로 스틱키의 침착성 변화를 볼 수 있도록 하였고, 또한 현장조건 에 적합하도록 다량의 지료분석과 손쉬운 작동이 가능케 하였다. 제작된 마 이크로 스틱키 정량설비를 이용하여 현장 플로테이션 공정을 대상으로 마이 크로 스틱키를 정량한 결과 리젝트의 지료에서 더 많은 량의 마이크로 스틱 키가 존재함을 확인하였다. 이는 소수성의 마이크로 스틱키가 기포와 함께 리젝트로 배출되고 있음을 보여주고 있으며, 또한 3종의 분급된 지료에서 와 이어상에서 탈수된 각각의 백수를 분석함으로써 백수 재활용에 따른 마이크 로 스틱키의 농축현상올 밝혔다. 플로테이션 과정중에 마이크로 스틱키의 거동 파악과 제어를 향상시키기 위하여 MCC를 이용하여 준비된 마이크로 스틱키 모텔물질을 이용하여 실험 실적 부유부상 실험을 실시하였다. 이를 통하여 플로테이션 공정의 마이크로 스틱키 제어 최적화 방안과 고농도의 마이크로 스틱키를 함유한 지료의 처 리를 방안을 검토하였다.