• Title/Summary/Keyword: shape modeling

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Curvature stroke modeling for the recognition of on-line cursive korean characters (온라인 흘림체 한글 인식을 위한 곡률획 모델링 기법)

  • 전병환;김무영;김창수;박강령;김재희
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.11
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    • pp.140-149
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    • 1996
  • Cursive characters are written on an economical principle to reduce the motion of a pen in the limit of distinction between characters. That is, the pen is not lifted up to move for writing a next stroke, the pen is not moved at all, or connected two strokes chance their shapes to a similar and simple shape which is easy to be written. For these reasons, strokes and korean alphabets are not only easy to be changed, but also difficult to be splitted. In this paper, we propose a curvature stroke modeling method for splitting and matching by using a structural primitive. A curvature stroke is defined as a substroke which does not change its curvanture. Input strokes handwritten in a cursive style are splitted into a sequence of curvature strokes by segmenting the points which change the direction of rotation, which occur a sudden change of direction, and which occur an excessive rotation Each reference of korean alphabets is handwritten in a printed style and is saved as a sequence of curvature strikes which is generated by splitting process. And merging process is used to generate various sequences of curvature strikes for matching. Here, it is also considered that imaginary strokes can be written or omitted. By using a curvature stroke as a unit of recognition, redundant splitting points in input characters are effectively reduced and exact matching is possible by generating a reference curvature stroke, which consists of the parts of adjacent two korean alphasbets, even when the connecting points between korean alphabets are not splitted. The results showed 83.6% as recognition rate of the first candidate and 0.99sec./character (CPU clock:66MHz) as processing time.

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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Influence of Female Undergraduates upon Sociality and College Life Satisfaction (여대생의 사회성과 대학생활 만족도에 미치는 영향)

  • Lee, Myeong-Jin;Lee, Jung-Min;Lee, Jin-Min;Choi, Bong-Joon;Chun, Jin-Ho;Sohn, Hae-Sook
    • The Journal of the Korea Contents Association
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    • v.12 no.8
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    • pp.300-309
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    • 2012
  • The purpose of this study was to understand about the influence of female undergraduates health behavior and health state upon sociality and the influence of sociality upon college life satisfaction. The subjects were 335 female junior-college students with major related to public health in Busan, Daegu, and Gyeongnam and were carried out questionnaire survey on general characteristics, sociality, college life satisfaction, health behavior, health status, and internet addiction. An analytical method was made through chi-square test, t-test, one-way ANOVA, ANOVA for trend, and structural equation modeling(SEM). As a result, the influence of accountability had the greatest influence as sub-factor. Accountability and age had a positive correlation(p<0.001). Accountability was low when self-cognitive body shape was very thin(p=0.005). In sociality, full age(p<0.001), self rated health(p<0.001), and physical education instruction for the 3rd grade of high school(p=0.004) showed direct effect. Also, sociality showed direct influence upon college life satisfaction. The older age, the higher self rated health, and the more instruction for the 3rd grade of high school led to the higher sociality, thereby having been indicated to be higher in college life satisfaction. Accordingly, a multi-dimensional effort is judged to be necessary for reinforcing physical education activity for high school students and for improving their quality of life as a plan for increasing college life satisfaction.

A Study on the Seismic Response of a Non-earthquake Resistant RC Frame Using Inelastic Dynamic Analyses (비선형 동적 해석을 이용한 비내진 상세 RC 골조의 지진거동 특성 분석)

  • Jeong, Seong-Hoon;Lee, Kwang-Ho;Lee, Soo-Kueon
    • Journal of the Korea Concrete Institute
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    • v.22 no.3
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    • pp.381-388
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    • 2010
  • In this study, characteristics of the seismic response of the non-earthquake resistant reinforced concrete (RC) frame were identified. The test building is designed to withstand only gravity loads and not in compliance with modern seismic codes. Smooth bars were utilized for the reinforcement. Members are provided with minimal amount of stirrups to withstand low levels of shear forces and the core concrete is virtually not confined. Columns are slender and more flexible than beams, and beam-column connections were built without stirrups. Through the modeling of an example RC frame, the feasibility of the fiber elementbased 3D nonlinear analysis method was investigated. Since the torsion is governed by the fundamental mode shape of the structure under dynamic loading, pushover analysis cannot predict torsional response accurately. Hence, dynamic response history analysis is a more appropriate analysis method to estimate the response of an asymmetric building. The latter method was shown to be accurate in representing global responses by the comparison of the analytical and experimental results. Analytical models without rigid links provided a good estimation of reduced stiffness and strength of the test structure due to bond-slip, by forming plastic hinges closer to the column ends. However, the absence of a proper model to represent the bond-slip poased the limitations on the current inelastic analysis schemes for the seismic analysis of buildings especially for those with round steel reinforcements. Thus, development of the appropriate bond-slip model is in need to achieve more accurate analysis.

Simulations of the Flow and Distribution of LNAPL in Heterogeneous Porous Media under Water Table Fluctuation Condition (불균질한 다공성 매질에서의 지하수위 변동을 고려한 저밀도 비수용성유체(LNAPL)의 흐름 모의)

  • 천정용;이진용;이강근
    • The Journal of Engineering Geology
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    • v.13 no.1
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    • pp.51-65
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    • 2003
  • A series of numerical simulations were carried out using STOMP( Subsurface Transport over Multiple Phase) simulator. The flow and distribution of LNAPL were analyzed in homogeneous fine and coarse sand. Vertical movement of LNAPL is faster in the coarser sand. But the total volume of LNAPL retained in the unsaturated zone is larger in the finer sand. A fine layer in the coarse sand domain is also simulated. The results showed that the retained LNAPL volume and shape are highly influenced by the Position of the fine layer. Flow and distributions of LNAPL were simulated when there were heterogeneous lenses in the sand domain. Water table fluctuation was also considered. In these cases, it was found that the heterogeneous lens was a barrier to LNAPL flow, and water table fluctuation stimulated the downward movement of retained LNAPL. The LNAPL flow and distribution observed in these numerical experiments show that in the subsurface environment, the behaviors of LNAPL highly depend on heterogeneities of unsaturated zone and the dynamic hydrogeologic condition such as water table fluctuation. These results can explain some of the complexity of LNAPL flow and distribution Patterns in LNAPL contaminated field sites.

A Study on the reduction of surface roughness by analyzing the thickness of photocurable sculpture (광조형물의 패턴두께에 따른 표면 거칠기 저감을 위한 공정연구)

  • Kim, Young-Su;Yang, Hyoung-Chan;Kim, Go-Beom;Dang, Hyun-Woo;Doh, Yang-Hoi;Choi, Kyung-Hyun
    • Journal of Power System Engineering
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    • v.20 no.4
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    • pp.75-82
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    • 2016
  • In this paper, we developed a 3D printing system using a photo-curing resin in order to reduce the surface roughness of a sculpture produced with the 3D printer. Using the pattern of the resulting variable thickness, that gave rise to a stepped shape, and the area error of the photo-curable sculpture, a study was carried out for the process to reduce the surface roughness. At a given value of stage velocity (40~70 mm/s) and output air pneumatic pressure (20~60 kPa), the minimum pattern thickness of the pattern was achieved $65{\mu}m$ and the maximum pattern thickness of up to $175{\mu}m$. To increases the pattern resolution to about $40{\mu}m$, the process conditions should be optimized. 3D surface Nano profiler was used to find the surface roughness of the sculpture that was measured to be minimum $4.7{\mu}m$ and maximum $8.7{\mu}m$. The maximum surface roughness was reduced about $1.2{\mu}m$ for the maximum thickness of the pattern. In addition, a FDM was used to fabricate the same sculpture and its surface roughness measurements were also taken for comparison with the one fabricated using photo-curing. Same process conditions were used for both fabrication setups in order to perform the comparison efficiently. The surface roughness of the photo-curable sculpture is $5.5{\mu}m$ lower than the sculpture fabricated using FDM. A certain circuit patterns was formed on the laminated surface of the photo-curable sculpture while there was no stable pattern on the laminated surface of the FDM based sculpture the other hand.

A Study on the Corelation between the Variation of Land Cover and Groundwater Recharge Using the Analysis of Landsat-8 OLI Data (Landsat-8 위성을 통한 토지피복 변화와 지하수 함양량 상관성 고찰)

  • Park, Seunghyuk;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.30 no.3
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    • pp.347-378
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    • 2020
  • Based on monthly average groundwater recharge over a nearly 10 year period, results of fully integrated hydrologic modeling of SWAT-MODFLOW, land cover, land use, soil type and hydrologic response unit (HRU) was used to assess the dominant influencing factors of groundwater recharge spatial patterns in Jangseong district. As dominant factors, land cover was FRSE (forest-evergreen) and soil type was Samgag. Landsat-8 OLI imaging spectrometer data were acquired in the period 2003 to 2004 and seasonal bare soil lines (BSL) were estimated through NIR-RED plot. Extent of slope of BSL was from 1.092 to 1.343 and the intercept was from -0.004 to -0.015. To know correlation between spatial groundwater recharge and soil-vegetation indices (PVI, NDVI, NDTI, NDRI), this study employed frequency and regression analysis. On May, RED band increased up 3 to 4 times compared to other seasons and only one turning point appeared as recharge-index with upward parabola bell shape as results of existing research. Considering precipitation, if the various studies for relationship between groundwater recharge and soil-vegetation index just like NDVI are performed, it is possible to estimate groundwater recharge through analyzing remote sensing data.

Dynamic analysis of slack moored spar platform with 5 MW wind turbine

  • Seebai, T.;Sundaravadivelu, R.
    • Ocean Systems Engineering
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    • v.1 no.4
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    • pp.285-296
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    • 2011
  • Spar platforms have several advantages for deploying wind turbines in offshore for depth beyond 120 m. The merit of spar platform is large range of topside payloads, favourable motions compared to other floating structures and minimum hull/deck interface. The main objective of this paper is to present the response analysis of the slack moored spar platform supporting 5MW wind turbine with bottom keel plates in regular and random waves, studied experimentally and numerically. A 1:100 scale model of the spar with sparD, sparCD and sparSD configuration was studied in the wave basin ($30{\times}30{\times}3m$) in Ocean engineering department in IIT Madras. In present study the effect of wind loading, blade dynamics and control, and tower elasticity are not considered. This paper presents the details of the studies carried out on a 16 m diameter and 100 m long spar buoy supporting a 90 m tall 5 MW wind turbine with 3600 kN weight of Nacelle and Rotor and 3500 kN weight of tower. The weight of the ballast and the draft of the spar are adjusted in such a way to keep the centre of gravity below the centre of buoyancy. The mooring lines are divided into four groups, each of which has four lines. The studies were carried out in regular and random waves. The operational significant wave height of 2.5 m and 10 s wave period and survival significant wave height of 6 m and 18 s wave period in 300 m water depth are considered. The wind speed corresponding to the operational wave height is about 22 knots and this wind speed is considered to be operating wind speed for turbines. The heave and surge accelerations at the top of spar platform were measured and are used for calculating the response. The geometric modeling of spar was carried out using Multisurf and this was directly exported to WAMIT for subsequent hydrodynamic and mooring system analysis. The numerical results were compared with experimental results and the comparison was found to be good. Parametric study was carried out to find out the effect of shape, size and spacing of keel plate and from the results obtained from present work ,it is recommended to use circular keel plate instead of square plate.

Preliminary Study on Factor Technology of Selective Catalytic Reduction System in Marine Diesel Engine (선박용 디젤엔진 SCR 시스템 요소 기술에 관한 기초 연구)

  • Park, Yoon-Yong;Song, Ha-Cheol;Ahn, Gi-Ju;Shim, Chun-Sik
    • Journal of Navigation and Port Research
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    • v.40 no.4
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    • pp.173-181
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    • 2016
  • From 2016, controls on reduction of NOx and SOx emissions from the vessels that are operated in the emission control area were tightened. The selectivity catalytic reduction system of the denitrification equipment which NOx among the above controlled materials is very effective and used commercially very much. But it has the disadvantage that CSR is activated at high temperatures. Therefore, the SCR and SCR activation instrument that can react even at low temperatures by using micro-nano bubbles so that the above problems can be minimized were developed. And the computational fluid dynamics technique was used by ANSYS-CFX package to prepare the plan that improves the SCR system's efficiency. Simulation for the viscous flow analysis of the SCR system was executed by applying the Navier-Stokes equation to it as a governing equation. For the SCR system's shape, 3D modeling was done by using CATIA V5. SCR jet nozzle's position was checked by changing it to the intervals of 1/3, 1/2, and 2/3 from the inlet of the vent pipe to compare the SCR system's efficiency. And the number of nozzles was compared and analyzed by simulating 4, 6, and 8 holes to check an effect of the number on the SCR system's efficiency. The simulation result has found that the closer nozzles are to the inlet of the vent pipe and the more nozzles are, the more efficiency is improved.

Distribution of Electrically Conductive Sedimentary Layer in Jeju Island Derived from Magnetotelluric Measurements (MT 탐사자료를 이용한 제주도 지역의 전도성 퇴적층 분포 연구)

  • Lee, Choon-Ki;Lee, Heuisoon;Oh, Seokhoon;Chung, Hojoon;Song, Yoonho;Lee, Tae Jong
    • Geophysics and Geophysical Exploration
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    • v.17 no.1
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    • pp.28-33
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    • 2014
  • We investigate the spatial distribution of highly conductive layer using the one-dimensional inversions of the new magnetotelluric (MT) measurements obtained at the mid-mountain (400 ~ 900 m in elevation) western area of Jeju Island and the previous MT data over Jeju Island, Korea. The conductive layer indicates the sedimentary layer comprised of Seoguipo Fomation and U Formation. There is a definite positive correlation between the top of conductive layer and the earth surface in elevation. On the contrary, the bottom of conductive layer has a negative correlation with the surface elevation. In other words, the conductive layer has a shape of convex lens, which is thickest in the central part. The basement beneath the conductive layer could be concave in the central part of Jeju Island. A kriging considering the correlation between the layer boundary and the surface elevation provides a reliable geoelectric structure model of Jeju Island. However, further studies, i.e. three-dimensional modeling and interpretation integrated with other geophysical or logging data, are required to reveal the possible presence of three-dimensional conductive body near the subsurface vent of Mt. Halla and the causes of the bias in the depths of layer estimated from MT and core log data.