• Title/Summary/Keyword: design characteristic

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Development of a 300W Generator for Lightweight Wind Turbine

  • Lee, Hee-Kune;Lee, Hee-Joon;Kim, Sun-Hyung
    • The Journal of Korean Institute of Information Technology
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    • v.15 no.12
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    • pp.181-188
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    • 2017
  • As a population of leisure activities grows and diversifies, there is a great demand for portable and environment-friendly power generation systems. A small wind power generation system is emerging as a suitable power generation equipment to meet these needs. The most important thing when developing a small portable wind turbine is to reduce the weight of the generator and increase the efficiency. The existing 300W wind turbine generator weighs about 10kg, which is heavy to carry. Therefore, a new generator weighing less than 4kg to make it easy to carry with high efficiency has been developed. In addition, considering complicated characteristics of wind volume and topography of Korea, a small wind turbine that can be used in urban and rural areas individually was constructed. Through basic designing and optimization, the lightweight and efficient generator was manufactured. It is a 300W wind turbine designed and fabricated with reduced weight as a prototype. The average output voltage of the generator was 24.7V at 900rpm no-load test. On a load test with the average line voltage 36.8V and the average phase current 2.62A, when the mechanical input was 339.84W, an average voltage output of the generator was measured as 289.5W with efficiency of 85.18%. The generator weight was 3.84kg.

A Flat Staging Studies in the Animation "Song of the Sea(2014)" (애니메이션 "바다의 노래(2014)"에 나타난 평면적 스테이징 연구)

  • Kim, Soong-Hyun;Lee, Tae-Hoon
    • Journal of Digital Convergence
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    • v.17 no.6
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    • pp.373-380
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    • 2019
  • In this study, I examined the visual elements for narrative structure and the symbols, scene components and visual styles in the images through analyze the flat staging in Tomm Moore's animated feature film, . As a research method, I figure out the general theories about staging and analyze extracted scenes which revealed flat staging in the , then summarize and clarify the flat staging production elements and features of Tomm Moore. As a result, in , the composition of the screen using the basic shapes, the screen composition containing the spiral which is symbol of the Celtic traditional pattern, the stable and flat frame expression through the balanced screen composition, expression of spatial sensation using perspective, appearance of the period by using the inverted perspective, and composition that can emphasize the flat formability are appeared as a characteristic. Through this, the two-dimensional planarity was maximized to convey the feeling of appreciating the illustrations of fairy tales. Tomm Moore, who produced animation based on folk tales in order to inherit the traditional culture of Ireland, has been attracting worldwide attention because of its flat staging to help narrative, enhancing the original expression and performance of animation. I hope that this study will be used as basic data for industry workers and researchers who make unique and excellent animated feature film.

A Full Scale Hydrodynamic Simulation of High Explosion Performance for Pyrotechnic Device (파이로테크닉 장치의 고폭 폭발성능 정밀 하이드로다이나믹 해석)

  • Kim, Bohoon;Yoh, Jai-ick
    • Journal of the Korea Society for Simulation
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    • v.28 no.2
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    • pp.1-14
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    • 2019
  • A full scale hydrodynamic simulation that requires an accurate reproduction of shock-induced detonation was conducted for design of an energetic component system. A detailed hydrodynamic analysis SW was developed to validate the reactive flow model for predicting the shock propagation in a train configuration and to quantify the shock sensitivity of the energetic materials. The pyrotechnic device is composed of four main components, namely a donor unit (HNS+HMX), a bulkhead (STS), an acceptor explosive (RDX), and a propellant (BPN) for gas generation. The pressurized gases generated from the burning propellant were purged into a 10 cc release chamber for study of the inherent oscillatory flow induced by the interferences between shock and rarefaction waves. The pressure fluctuations measured from experiment and calculation were investigated to further validate the peculiar peak at specific characteristic frequency (${\omega}_c=8.3kHz$). In this paper, a step-by-step numerical description of detonation of high explosive components, deflagration of propellant component, and deformation of metal component is given in order to facilitate the proper implementation of the outlined formulation into a shock physics code for a full scale hydrodynamic simulation of the energetic component system.

Development of methodology for daily rainfall simulation considering distribution of rainfall events in each duration (강우사상의 지속기간별 분포 특성을 고려한 일강우 모의 기법 개발)

  • Jung, Jaewon;Kim, Soojun;Kim, Hung Soo
    • Journal of Korea Water Resources Association
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    • v.52 no.2
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    • pp.141-148
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    • 2019
  • When simulating the daily rainfall amount by existing Markov Chain model, it is general to simulate the rainfall occurrence and to estimate the rainfall amount randomly from the distribution which is similar to the daily rainfall distribution characteristic using Monte Carlo simulation. At this time, there is a limitation that the characteristics of rainfall intensity and distribution by time according to the rainfall duration are not reflected in the results. In this study, 1-day, 2-day, 3-day, 4-day rainfall event are classified, and the rainfall amount is estimated by rainfall duration. In other words, the distributions of the total amount of rainfall event by the duration are set using the Kernel Density Estimation (KDE), the daily rainfall in each day are estimated from the distribution of each duration. Total rainfall amount determined for each event are divided into each daily rainfall considering the type of daily distribution of the rainfall event which has most similar rainfall amount of the observed rainfall using the k-Nearest Neighbor algorithm (KNN). This study is to develop the limitation of the existing rainfall estimation method, and it is expected that this results can use for the future rainfall estimation and as the primary data in water resource design.

Cut-off Value for Body Mass Index in Predicting Surgical Success in Patients with Lumbar Spinal Canal Stenosis

  • Azimi, Parisa;Yazdanian, Taravat;Shahzadi, Sohrab;Benzel, Edward C.;Azhari, Shirzad;Aghaei, Hossein Nayeb;Montazeri, Ali
    • Asian Spine Journal
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    • v.12 no.6
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    • pp.1085-1091
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    • 2018
  • Study Design: Case-control. Purpose: To determine optimal cut-off value for body mass index (BMI) in predicting surgical success in patients with lumbar spinal canal stenosis (LSCS). Overview of Literature: BMI is an essential variable in the assessment of patients with LSCS. Methods: We conducted a prospective study with obese and non-obese LSCS surgical patients and analyzed data on age, sex, duration of symptoms, walking distance, morphologic grade of stenosis, BMI, postoperative complications, and functional disability. Obesity was defined as BMI of ${\geq}30kg/m^2$. Patients completed the Oswestry Disability Index (ODI) questionnaire before surgery and 2 years after surgery. Surgical success was defined as ${\geq}30%$ improvement from the baseline ODI score. Receiver operating characteristic (ROC) analysis was used to estimate the optimal cut-off values of BMI to predict surgical success. In addition, correlation was assessed between BMI and stenosis grade based on morphology as defined by Schizas and colleague in total, 189 patients were eligible to enter the study. Results: Mean age of patients was $61.5{\pm}9.6years$. Mean follow-up was $36{\pm}12months$. Most patients (88.4%) were classified with grades C (severe stenosis) and D (extreme stenosis). Post-surgical success was 85.7% at the 2-year follow-up. A weak correlation was observed between morphologic grade of stenosis and BMI. Rates of postoperative complications were similar between patients who were obese and those who were non-obese. Both cohorts had similar degree of improvement in the ODI at the 2-year followup. However, patients who were non-obese presented significantly higher surgical success than those who were obese. In ROC curve analysis, a cut-off value of ${\leq}29.1kg/m^2$ for BMI in patients with LSCS was suggestive of surgical success, with 81.1% sensitivity and 82.2% specificity (area under the curve, 0.857; 95% confidence interval, 0.788-0.927). Conclusion: This study showed that the BMI can be considered a parameter for predicting surgical success in patients with LSCS and can be useful in clinical practice.

The Distribution and Habitat Characteristic of Tscherskia triton (Rodentia; Cricetidae) in Jeju Island, Korea (제주도에 서식하는 비단털쥐(Tscherskia triton) (설치목; 비단털쥐과)의 분포 현황 및 서식지 특성)

  • Park, Jun-Ho;Kim, Kang Il;Kim, Man-Ho;Oh, Hong-Shik
    • Korean Journal of Environmental Biology
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    • v.36 no.3
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    • pp.412-423
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    • 2018
  • In this study, we investigated the distribution and habitat of Tscherskia triton from 2014 to 2016 in Jeju Island. Nine individuals of T. triton were observed and captured from four habitat sites. Most of the habitats were of the natural and rural type, and urban type coexisted in some of the areas. The natural type of habitat comprised of forests, shrubs, and grasslands. The habitat of T. triton ranged vertically from 102 m in lowland to 742 m in a mountainous area and was not observed in altitude over 1,000 m. Small brooks, dry streams or wetlands were found to be located nearby the habitat of T. triton. The T. triton was distributed mainly in areas with natural vegetation and artificial plantation in company with the upper story vegetation on the ground of intact or incomplete layer structure, or the area with the relatively large distribution of shrubs and long grassland. The presence of roads and forest paths in these habitats suggested that the T. triton can thrive in areas with human disturbance. The designation of Halla Mountain National Park in Jeju Island as a conservation area prevents damage or loss of the habitat due to any artificial development. However, frequent human disturbances occurring in grassland is tolerated by small mammals. Therefore, in order to help T. triton maintain a stable population density, it is essential that various types of the habitat should be conserved in the middle mountain areas and the grasslands in lowlands should be well protected.

A Study on the Output and Reliability Characteristics of Ultra Barrier Film PV Module (고분자 보호 필름을 적용한 태양광 모듈의 출력 및 신뢰성에 관한 연구)

  • Lim, Jong Rok;Shin, Woo Gyun;Yoon, Hee Sang;Kim, Yong Sung;Ju, Young-Chul;Ko, Suk-Whan;Kang, Gi-Hwan;Hwang, Hye-Mi*
    • Journal of the Korean Solar Energy Society
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    • v.39 no.5
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    • pp.1-10
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    • 2019
  • Recently, the installation capacity of PV (photovoltaic) systems has been increasing not only field installation but also floating PV, farm land, BIPV/BAPV. For this reason, the new design and materials of PV module are needed. In particular, in order to apply a PV system to a building, lightweight of the PV module is essential. PV modules made of generally used texturing glass are excellent in output and reliability, but there is a limit to the weight that can be reduced. For the lightweight of the PV module, it necessary to use a film instead of a glass. However, the application of film rather than a glass may cause various problems such as decrease in photocurrent by decrease in transmittance and a increase of CTM (cell to module) loss, a degradation of the reliability, and so on. In this paper, PV modules using Ultra barrier film, which is recently a lot of interest as a substitute for a glass, its characteristic analysis and reliability test were conducted. The transmittance and UV characteristics of each material were verified, and the output of the fabricated 1 cell PV module was measured. In addition, 24 cell PV modules were fabricated at the lab-scale and its reliability tests were conducted. As a result of the experiment, the reliability characteristics of the ultra barrier film PV module were excellent, and it was confirmed that it could be used as the front material of the PV module instead of glass

A Study on the Acquisiton Methods of Theater Collections (연극기록물의 수집방안 연구)

  • Jung, Eun Jin
    • The Korean Journal of Archival Studies
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    • no.29
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    • pp.35-78
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    • 2011
  • This study is intended to recommend for acquisition methods of the theatre collection. Theatre activities is representative of the performing arts, and the Korea theatre history start from the modern history of Korea. In the meantime, theatre collections has already been lost by a lack of effort and management, and scattered most of the collections. In particular, a one-off nature and volatility of theatrical performances make future generations to enjoy the performances and to study should consult the relevant records. Therefore, collecting records can be very serious mission. In this study, theatre collections of the country which aims to collect and analyze the characteristics and type of theatre collections. Based on this information, collection scope, targets, priorities, acquisition level, method of collecting are proposed the following. First, collection scope is defined for the theatre related collections which was performed nationwide in the 1900s, the times that modern theatre was begun. The object includes related information of planning, administration, drama (script), directing, stage design, public relations, production, evaluation, personal records, biographical data, group data and space data. Second, the theatre collections are divided into records and historical records. Priority of collections object is determined by the historical value and the theatre performed by the support of public organization. Third, the acquisition level is divided into archived, mirrored, web linked and database, which is proposed by the determined levels of mandatory, recommend and discretion according to the characteristic of performance. Fourth, acquisition methods are suggested by the general acquisition methods of transfer, donation and purchase as well as the methods of copy, production, legal deposit, entry and web link etc. The acquisition of theatre collections is executed on digital-based environment, and a centralized authority control should be establishmented. And through the development of network with theatre's stakeholders and the cooperation of related organizations, theatre collections acquisition is feasible.

Structural Characteristics of Ar-N2 Plasma Treatment on Cu Surface (Ar-N2 플라즈마가 Cu 표면에 미치는 구조적 특성 분석)

  • Park, Hae-Sung;Kim, Sarah Eunkyung
    • Journal of the Microelectronics and Packaging Society
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    • v.25 no.4
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    • pp.75-81
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    • 2018
  • The effect of $Ar-N_2$ plasma treatment on Cu surface as one of solutions to realize reliable Cu-Cu wafer bonding was investigated. Structural characteristic of $Ar-N_2$ plasma treated Cu surface were analyzed using X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscope. Ar gas was used for a plasma ignition and to activate Cu surface by ion bombardment, and $N_2$ gas was used to protect the Cu surface from contamination such as -O or -OH by forming a passivation layer. The Cu specimen under high Ar partial pressure plasma treatment showed more copper oxide due to the activation on Cu surface, while Cu surface after high $N_2$ gas partial pressure plasma treatment showed less copper oxide due to the formation of Cu-N or Cu-O-N passivation layer. It was confirmed that nitrogen plasma can prohibit Cu-O formation on Cu surface, but nitrogen partial pressure in the $Ar-N_2$ plasma should be optimized for the formation of nitrogen passivation layer on the entire surface of Cu wafer.

Understanding of Intrauterine Environment Changes based on Proteomics and Bioinformatics during Estrous Cycle (단백체학과 생물정보학을 이용한 자궁 내 환경의 이해)

  • Lee, Sang-Hee;Lee, Seunghyung
    • Journal of Life Science
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    • v.29 no.5
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    • pp.621-630
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    • 2019
  • Fertilization is the beginning of a new life that occurs in the female uterine. The female reproductive tract is composed ovary, oviduct, uterine, vagina and cervix, their physiological features are regulated by estrous cycle. Of these, uterine is a main point to establish embryo development and implantation, and intercommunication between embryo and uterine environment is necessary for suitable pregnancy. Endometrium is part of the uterine, its morphology is repetitively changed by hormones, and characteristic of uterine fluid from endometrium is also changed. Recently, massive proteins of endometrium and uterine fluid can be detected according to develop proteomics and bioinformatics and have been accelerated the understanding of the reproductive biology fields. Moreover, the massive protein information is actively studying with deeply studied theory such as sex hormone signal pathway and angiogenesis in mammals. In this paper, we review understanding of endometrium remodeling, uterine gland and fluid during estrous cycle, additionally studies on endometrium and uterine fluid based on proteomics techniques. Lastly, we introduced methods of the protein-protein correlation using bioinformatics tool that interaction with hormone receptors, representative angiogenetic factors and detected proteins using proteomics in endometrium and uterine fluid. This review will be useful to understanding the study on search of new cell mechanism in endometrium and uterine fluid.