• Structural Engineering and Mechanics
• /
• 제43권6호
• /
• pp.795-821
• /
• 2012

The size and topology of geometrically nonlinear dome structures are optimized thereby minimizing both its entire weight & joint (node) displacements and maximizing load-carrying capacity. Design constraints are implemented from provisions of American Petroleum Institute specification (API RP2A-LRFD). In accordance with the proposed design constraints, the member responses computed by use of arc-length technique as a nonlinear structural analysis method are checked at each load increment. Thus, a penalization process utilized for inclusion of unfeasible designations to genetic search is correspondingly neglected. In order to solve this complex design optimization problem with multiple objective functions, Non-dominated Sorting Genetic Algorithm II (NSGA II) approach is employed as a multi-objective optimization tool. Furthermore, the flexibility of proposed optimization is enhanced thereby integrating an automatic dome generating tool. Thus, it is possible to generate three distinct sphere-shaped dome configurations with varying topologies. It is demonstrated that the inclusion of brace (diagonal) members into the geometrical configuration of dome structure provides a weight-saving dome designation with higher load-carrying capacity. The proposed optimization approach is recommended for the design optimization of geometrically nonlinear dome structures.

• 전자공학회논문지B
• /
• 제33B권2호
• /
• pp.10-19
• /
• 1996

This paper presents a finger-shaped multisensor system which can measure the tyep and position of a target surface by contactl. The multi-sensor system consists of a sphere-shpaed optical tactile sensor located at the finger tip and a force/torque sensor located at the joint of a finger. The optial tactile sensor determines the type and position of the target surface using the shape and position of the CCD image of the touching area generated by a contact between the sensor and the taget surface. The force/torque sensor also determines the position and surface normal vector by applying the distributionof forces and torques t the contact point to the equations of finger shape. The measurements on the position and surface normal vector at a contact point obtined by two individual sensors are fused using a statistical method. The integrated sensor system has 0.8mm error in position measurement and 1.31$^{\circ}$ error in normal vector measurement. The developed sensor system has many applications, such as autonomous compliance control, automatic grasping and recognition, etc.

• 전기학회논문지
• /
• 제58권2호
• /
• pp.369-372
• /
• 2009

When measuring the luminous flux of a light source at the integrating sphere photometer, it can know the luminous flux to compare the standard lamp with the specimen lamp at the same location. But in case of PLS(plasma lighting system, microwave discharged lamp), that two lamps are cannot be the same location. If the reference illuminant and specimen lamp are cannot measure identical location, we should measure the variation of the luminous flux. For the outcome we can turn out a correction factor to revise and reflect it. But the better way is calibrate the specimen lamp locate the identical location of reference illuminant measured. In this thesis, we've test to find the correction factor for consider that change the measuring location. And it turns out the correction factor. From this, it presents the result to make a select for the reference illuminant which is against the illuminant type for newly produce.

• 조명전기설비학회논문지
• /
• 제15권1호
• /
• pp.1-6
• /
• 2001

조명업체에서 적분구를 이용한 광원의 전광선속을 측정하는데 기준광원으로 활용하기 위하여 신뢰성 높은 전광선속 표준전구를 개발하였다. 전광선속 표준전구는 공간세기분포가 균일하도록 되어 있으며, 사용시간 100[h]동안에 전광선속 변화율이 0.5% 이내로 양호한 안정도를 갖는다.

• Asian Journal of Atmospheric Environment
• /
• 제6권4호
• /
• pp.268-274
• /
• 2012

To perform quick measurements of black carbon (BC) particles deposited on foliar surfaces of forest tree species, we investigated an optical method for measuring the amount of BC extracted from foliar surfaces and collected on quartz fiber filters. The seedlings of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica were exposed to submicron BC particles for one growing season (1 June to 7 December 2009). At the end of the growing season, the leaves or needles of the seedlings were harvested and washed with deionized water followed by washing with chloroform to extract the BC particles deposited on the foliar surfaces. The extracted BC particles were collected on a quartz fiber filter. The absorption spectrum of the filters was measured by spectrophotometer with an integrating sphere. To obtain the relationship between the absorbance of the filter and the amount of BC particles on the filter, the amount of BC particles on the filter was determined as that of elemental carbon (EC) measured by a thermal optical method. At wavelengths below 450 nm, the absorption spectrum of the filter showed absorption by biological substances, such as epicuticular wax, resulting in the low coefficient of determination ($R^2$) in the relationship between the amount of EC on the filter ($M_{EC}$, ${\mu}g\;C\;cm^{-2}$ filter area) and the absorbance of the filter. The intercept of the regression line between $M_{EC}$ and the absorbance of the filter at 580 nm ($A_{580}$) was closest to 0. There was a significant linear relationship between the $A_{580}$ and $M_{EC}$ ($R^2$=0.917, p<0.001), suggesting that the amount of BC particles collected on the filter can be predicted from the absorbance. This optical method might serve as a simple, fast and cost-effective technique for measuring the amount of BC on foliar surfaces.

• 대한의용생체공학회:의공학회지
• /
• 제44권6호
• /
• pp.450-464
• /
• 2023

Pulse oximetry, a non-invasive technique for evaluating blood oxygen saturation, conventionally depends on isolated measurements, rendering it vulnerable to factors like illumination profile, spatial blood flow fluctuations, and skin pigmentation. Previous efforts to address these issues through imaging systems often employed red and near-infrared illuminations with distinct profiles, leading to inconsistent ratios of transmitted light and the potential for errors in calculating spatial oxygen saturation distributions. While an integrating sphere was recently utilized as an illumination source to achieve uniform red and near-infrared illumination profiles on the sample surface, its bulkiness presented practical challenges. In this work, we have enhanced the pulse oximetry imaging system by transitioning illumination from an integrating sphere to a multi-wavelength LED configuration. This adjustment ensures simultaneous emission of red and near-infrared light from the same position, creating a homogeneous illumination profile on the sample surface. This approach guarantees consistent patterns of red and near-infrared illuminations that are spatially uniform. The sustained ratio between transmitted red and near-infrared light across space enables precise calculation of the spatial distribution of oxygen saturation, making our pulse oximetry imaging system more compact and portable without compromising accuracy. Our work significantly contributes to obtaining spatial information on blood oxygen saturation, providing valuable insights into tissue oxygenation in peripheral regions.

• 동아시아식생활학회지
• /
• 제20권4호
• /
• pp.619-627
• /
• 2010

Finality in presenting table has an important significance. A presentation method in table comes to have different directionality depending on objective and significance such as the appearance of presentation for the substantial use or the appearance of presentation for delivering message. In our life, the utility table came to have value more than what supplies nutrition. Simultaneously with it, the table came to have the significance as a place of communication. What is being indicated in a different form from this is the art table. The table-coordinate starts to occupy a position in one aesthetic sphere, aside from the functional part of having a meal and communication, and is attempting the entry as the art sphere. What two types have been researched and developed so far in the face of having clear difference is limited to the utility presentation. The utility presentation and the art presentation need to be progressed at the same time rather than being separately classified and thought. Pursuit only for utility leads to being unable to proceed with making a new thing. The art table coordinate will be able to function as the new awakening point in the position of proceeding with such table coordinate. When proceeding with maintaining the form of the existing utility table, a client fails to feel fresh. Thus, coming to give new awareness by integrating art will lead to being available effectively for creating another profit. Even the art table can apply the characteristic of the display table among characteristics of the utility table. The display table aims at creating profit through communication between buyer and seller. Thus, even through the art table, both effects called the occurrence in profit and the initiative in trend will be capable of being enjoyed totally. Accordingly, the presentation of two tables in the art table and the utility table has clearly different characteristic. However, given properly using difference in presentation of the two, the best effect will be possibly seen.

• 한국광학회지
• /
• 제35권2호
• /
• pp.61-70
• /
• 2024

400 nm부터 1,600 nm까지의 파장 영역에서 단일모드 광섬유에 결합된 12개의 다이오드 레이저 광원를 기반으로 하는 레이저 복사출력계 교정시스템을 소개한다. 본 시스템은 복사출력 측정위치에서 레이저 출력요동을 최소화하였고 모든 광원에 대해 비슷한 빔 크기를 갖는다. 또한 감응도의 비균일도 및 비선형성을 최소화하기 위해 적분구 기준기를 사용하였다. 이 교정시스템의 최소 측정불확도는 대부분의 레이저 파장에서 1.1% (k=2)로 추정된다.

• 한국전기전자재료학회논문지
• /
• 제23권9호
• /
• pp.691-695
• /
• 2010

A measurement method of the particle-based reflective display is proposed, estimated, and compared with reported method. The reflectivity measurement by previous studies is simply obtained by integrating sphere, but it has a limitation for the estimation of real moving particles because its data include surface reflection and incomplete attachment on electrodes. To get the number of real moving particles, the area by attached particles on the electrodes is calculated at microscopic signals. The moving particles on subthreshold voltage are observed and this fluctuational variation of surface on subthreshold voltage gives a tip to understand the driving mechanism. By this measurement we ascertained the relationship of a particle layer and real driving particles, and the feasibility of observation and estimation for moving color particles, which were measured by the reflectivity and CIE (Commission Internationale de I'Eclairage) system of color specification at previous studies.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
• /
• pp.804-807
• /
• 2006

The SRI(Super Resolution Imager) with 800mm aperture primary mirror is the ground development model of the high resolution satellite camera. The SRI focal plane electronics including detector array generates the data for high-resolution images by converting incoming light into digital stream of pixel data. Since the focal plane including a detector is the basic building block of the camera system, the main system performances is directly determined by its performance. This paper measures the SRI focal plane electronics’ performance such as the dark signal, the dark signal noise, the linearity, the PRNU(Photo Response Non-Uniformity), the SNR(Signal to Noise Ratio) and the sensor saturation capability. In addition, this paper verifies the various functionalities of the SRI focal plane electronics. The electrical test equipment with the specialized software and the optical test equipments such as the integrating sphere, the rotation stage and the target are implemented and used to verify these functionalities and performances.