• Title/Summary/Keyword: structured-light

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Concepts of System Function and Modulation-Demodulation based Reconstruction of a 3D Object Coordinates using Active Method (시스템 함수 및 변복조 개념 적용 능동 방식 3차원 물체 좌표 복원)

  • Lee, Deokwoo;Kim, Jisu;Park, Cheolhyeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.5
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    • pp.530-537
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    • 2019
  • In this paper we propose a novel approach to representation of the 3D reconstruction problem by employing a concept of system function that is defined as the ratio of the output to the input signal. Akin to determination of system function (or system response), this paper determines system function by choosing (or defining) appropriate input and output signals. In other words, the 3D reconstruction using structured circular light patterns is reformulated as determination of system function from input and output signals. This paper introduces two algorithms for the reconstruction. The one defines the input and output signals as projected circular light patterns and the images overlaid with the patterns and captured by camera, respectively. The other one defines input and output signals as 3D coordinates of the object surface and the image captured by camera. The first one leads to the problem as identifying the system function and the second one leads to the problem as estimation of an input signal employing concept of modulation-demodulation theory. This paper substantiate the proposed approach by providing experimental results.

Implementation of a walking-aid light with machine vision-based pedestrian signal detection (머신비전 기반 보행신호등 검출 기능을 갖는 보행등 구현)

  • Jihun Koo;Juseong Lee;Hongrae Cho;Ho-Myoung An
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.17 no.1
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    • pp.31-37
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    • 2024
  • In this study, we propose a machine vision-based pedestrian signal detection algorithm that operates efficiently even in computing resource-constrained environments. This algorithm demonstrates high efficiency within limited resources and is designed to minimize the impact of ambient lighting by sequentially applying HSV color space-based image processing, binarization, morphological operations, labeling, and other steps to address issues such as light glare. Particularly, this algorithm is structured in a relatively simple form to ensure smooth operation within embedded system environments, considering the limitations of computing resources. Consequently, it possesses a structure that operates reliably even in environments with low computing resources. Moreover, the proposed pedestrian signal system not only includes pedestrian signal detection capabilities but also incorporates IoT functionality, allowing wireless integration with a web server. This integration enables users to conveniently monitor and control the status of the signal system through the web server. Additionally, successful implementation has been achieved for effectively controlling 50W LED pedestrian signals. This proposed system aims to provide a rapid and efficient pedestrian signal detection and control system within resource-constrained environments, contemplating its potential applicability in real-world road scenarios. Anticipated contributions include fostering the establishment of safer and more intelligent traffic systems.

A New Hardware Design for Generating Digital Holographic Video based on Natural Scene (실사기반 디지털 홀로그래픽 비디오의 실시간 생성을 위한 하드웨어의 설계)

  • Lee, Yoon-Hyuk;Seo, Young-Ho;Kim, Dong-Wook
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.11
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    • pp.86-94
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    • 2012
  • In this paper we propose a hardware architecture of high-speed CGH (computer generated hologram) generation processor, which particularly reduces the number of memory access times to avoid the bottle-neck in the memory access operation. For this, we use three main schemes. The first is pixel-by-pixel calculation rather than light source-by-source calculation. The second is parallel calculation scheme extracted by modifying the previous recursive calculation scheme. The last one is a fully pipelined calculation scheme and exactly structured timing scheduling by adjusting the hardware. The proposed hardware is structured to calculate a row of a CGH in parallel and each hologram pixel in a row is calculated independently. It consists of input interface, initial parameter calculator, hologram pixel calculators, line buffer, and memory controller. The implemented hardware to calculate a row of a $1,920{\times}1,080$ CGH in parallel uses 168,960 LUTs, 153,944 registers, and 19,212 DSP blocks in an Altera FPGA environment. It can stably operate at 198MHz. Because of the three schemes, the time to access the external memory is reduced to about 1/20,000 of the previous ones at the same calculation speed.

A New Strategy to Fabricate a Colloidal Array Templated $TiO_2$ Photoelectrode for Dye-sensitized Solar Cells

  • Lee, Hyeon-Jeong
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.8.1-8.1
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    • 2011
  • Nanocrystalline titanium dioxide ($TiO_2$) materials have been widely used as an electron collector in DSSC. This is required to have an extremely high porosity and surface area such that the dye can be sufficiently adsorbed and be electronically interconnected, resulting in the generation of a high photocurrent within cells. In particular, their geometrical structures and crystalline phase have been extensively investigated as important issues in improving its photovoltaic efficiency. In this study, we present a new strategy to fabricate a photoelectrode having a periodic structured $TiO_2$ film templated from 1D or 3D polystyrene (PS) microspheres array. Monodisperse PS spheres of various radiuses were used for colloidal array on FTO glasses and two types of photoelectrode structures with different $TiO_2$ materials were investigated respectively. One is the igloo-shaped electrode prepared by $TiO_2$ deposition by RF-sputtering onto 2D microsphere-templated substrates. At the interface between the film and substrate, there are voids formed by the decomposition of PS microspheres during the calcination step. These holes might be expected to play the predominant roles as scattering spherical voids to promote a light harvesting effect, a spacious structure for electrolytes with higher viscosity and effective paths for electron transfer. Additionally the nanocrystalline $TiO_2$ phase prepared by the RF-sputtering method was previously reported to improve the electron drift mobility within $TiO_2$ electrodes. This yields solar cells with a cell efficiency of 2.45% or more at AM 1.5 illumination, which is a very remarkable result, considering its $TiO_2$ electrode thickness (<2 ${\mu}m$). This study can be expanded to obtain higher cell efficiency by higher dye loading through the increase of surface area or multi-layered stacking. The other is the inverse opal photonic crystal electrode prepared by titania particles infusion within 3D colloidal arrays. To obtain the enlargement of ordered area and high quality of crystallinity, the synthesis of titania particles coated with a organic thin layer were applied instead of sol-gel process using the $TiO_2$ precursors. They were dispersed so well in most solvents without aggregates and infused successfully within colloidal array structures. This ordered mesoporous structure provides the large surface area leading to the enough adsorption of dye molecules and have an light harvesting effect due to the photonic band gap properties (back-and-forth reflection effects within structures). A major advantage of this colloidal array template method is that the pore size and its distribution within $TiO_2$ photoelectrodes are determined by those of latex beads, which can be controlled easily. These materials may have promising potentials for future applications of membrane, sensor and so on as well as solar cells.

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A Study for the Development of Standardized Management Manuel in Sanhujoriwon - Centered on the Management of Women & Newborn - (산후조리원의 표준화 관리 지침을 위한 연구 - 산모와 신생아 관리현황을 중심으로 -)

  • Jung, Eun-Sil;Yoo, Eun-Kwang
    • Women's Health Nursing
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    • v.8 no.2
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    • pp.301-313
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    • 2002
  • The purpose of this study was to develop the frame for standardized manual for Sanhujoriwon by finding out the status of the management of women & newborn in Sanhujoriwon, like postpartum care center. The subjects were 95 staffs of 22 Sanhujoriwon agreed on oral consent, in Seoul and Bundang, Korea. Data were collected from Sep. 15 to Oct. 24, 2001. The instrument used for this study was a structured questionnaire consisted of 16 items of general characteristics & educational characteristics about postpartum care, 31 items of degree of management of women's postpartum care (Cronbach's $\alpha$.93 ), 24 items of degree of management of newborn's care(Cronbach's $\alpha$.94 ), 10 items of methods of management of women's postpartum care, 8 items of methods management of newborn's care. The data were analyzed by the SPSS/PC+ program using frequency, percentage, mean, standard deviation, t-test, ANOVA and Pearson correlation coefficient. The results of the study were as follows ; 1. The mean of the degree of management for postpartum women was 4.1. The mean score for the degree of management of general postpartum care for women was 4.00 & traditional postpartum care(Sanhujori) was 4.20. The degree of management of traditional postpartum care was higher than general postpartum care for women. 2. The degree of management for newborn : The mean score for the degree of management of newborn was 4.37. 3.There was a strong positive correlation between general postpartum care and traditional postpartum care($r=.744^{**}$), and postpartum mother care and newborn care($r=.798^{**}$). 4.The basic frame for the management of the women and newborn in Sanhujoriwon. 1) For women: Integrated postpartal care Physical management : Vital sign & BP check, contraction of uterus, form and amount of lochia, management of personal hygiene, management of breast & breast-feeding, management of postpartum exercise, prevention of infection, symptom & sign of high risk and prevention & management of high risk condition; Emotional-psychological management: assessment and management of mother-baby attachment, emotional state; Educational management : education of vaccination schedule, urinary incontinence, rearing infant, breast-feeding ; and Environmental management : temperature, humidity, disinfection, cleaning, light, infection control integrated with 6 principles of Sanhujori. 2) For newborn Physical management : check of vital sign, management of umbilical cord, jaundice, prevention of infection, management of diaper rash; Emotional-psychological management : assessment of sleep, crying, activity, response of mother-baby attachment; and Environmental management : temperature, humidity, disinfection, cleaning, light, infection control integrated with 6 principles of Sanhujori. In conclusion Sanhujoriwon must be health care center for the postpartum women and newborn. Therefore, the establishment of various laws and regulations in such a way to meet the realistic needs of Sanhujoriwon as a health care center for women and infants future health should be done. The standardized management manual based on the results is absolutely required above all.

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Microstructure Analysis of Rabbit and Chicken Femurs by Light Microscopy and Transmission Electron Microscopy (광학현미경과 투과전자현미경을 이용한 토끼와 닭 대퇴골의 미세구조 분석)

  • Kim, Chang-Yeon;Kim, Eun-Kyung;Jeon, Tae-Hoon;Nam, Seung-Won;Kim, Youn-Joong
    • Applied Microscopy
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    • v.40 no.3
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    • pp.155-162
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    • 2010
  • Bone is a hierarchically structured composite material which has been well studied by the materials engineering community because of its unique structure and mechanical properties. Bone is a laminated organic-inorganic composite composed of primarily hydroxyapatite, collagen and water. The main mineral that gives bone's hardness is calcium phosphate, which is also known as hydroxyapatite. Light microscopy (LM) and transmission electron microscopy (TEM) were used to study the structure of femurs from chicken and rabbit. The elemental analysis was used to search variation in the distribution of calcium, potassium and oxygen in the femur. Current investigation focused on two structural scales: micro scale (arrangement of compact bone) and nano scale (collagen fibril and apatite crystals). At micro scale, distinct difference was found in microstructures of chicken femur and rabbit femur. At nano scale, we analyzed the shape and size of apatite crystals and the arrangement of collagen fibril. Consequently, femurs of chicken and rabbit had very similar chemical property and structures at nano scale despite of their different species.

Self-Assertiveness and Sexual Experiences of Teenage Girls in Korea (십대 여학생의 성 관련 경험과 자기주장)

  • Chang, Soon-Bok;Yoo, Myung-Sook;Lee, Sun-Kyung
    • Women's Health Nursing
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    • v.7 no.3
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    • pp.305-316
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    • 2001
  • The purpose of this study was to identify characteristics related to self assertiveness in teenage girls, and to identify the relationship between the self assertiveness and sexual experiences in teenage girls in Korea. The subjects for this study were 12,733 girls from an accessible population of 19,000 girls who were a multi-stage cluster sample from a population of 1,988,902 girls attending to 4,684 schools in the seven large cities and nine provinces of Korea. The response rate was 68.9%. Data were collected by mail from October 2 to October 28, 2000. A structured questionnaire of 125 items which included measurement of general characteristics, sexual experiences, and self-assertiveness was used. The sexual experiences were defined as dating, holding hands, putting arms on the shoulders, light kissing, French kissing, touching breasts, touching genitalia, and coitus. The self assertiveness measurement was developed by S. B. Chang et al.(2000) and has a Cronbach's alpha of .6031. Data was analyzed with SPSS 10.0 Program using descriptive statistics, reliability, and t-test. The results of this study are as follows; 1. The subjects were from 9th to 11th graders and 42.7% answered that they followed their partner's request. The range for the self assertiveness score was 7-21 out of a possible range of 7-21. The group of girls who were in vocational schools, lived away from family or in rural areas, attended night school, took part in drinking, smoking, and glue inhalation, who had cyber sex or phone sex or were exposed to pornography, and who had run away from home showed significantly lower self assertiveness scores than those without these characteristics (P<.05). 2. The group which had experience in dating(t=2.379, P=.017), French kissing (t=5.425, P=.000), touching breasts (t=8.637, P=.000), touching genitalia (t=6.057, P=.000), and coitus(t=6.057, P=.000) showed significantly lower self assertiveness scores than the group which had not had these sexual experiences. But there was no difference in the self assertiveness scores between the group which had experience of holding hands, light kissing, and using contraceptives compared to the group which did not. It can be concluded that the group which had delinquent behavior showed lower self assertiveness, and the lower self assertiveness led to unwanted sexual experiences. It is suggested that self assertiveness training be provided for the group with delinquent behavior as a first priority, and then analyze of the process of self assertiveness in relation to sexual experiences.

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A New Algorithm and High-Performance Hardware Design for 2-Dimensional Parallel Generation of Digital Hologram (디지털 홀로그램의 2차원적인 병렬 생성을 위한 알고리즘 및 고성능 하드웨어 설계)

  • Yang, Wol-Sung;Seo, Young-Ho;Kim, Dong-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.1
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    • pp.133-142
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    • 2012
  • In this paper, we propose and implement a high-speed algorithm for CGH that is to calculate digital hologram by modeling the interference phenomenon for tow lights. This algorithm changes the computation equations into a parallel-computable ones and implements it with a structure consisting of two kinds of cells (initial calculation cell, and update calculation cell). The parallel computation algorithm is to get the rest hologram pixels concurrently after calculation the first hologram column. Here, the initial calculation cells compute the first column of the hologram and the update calculation cells compute the rest of the hologram. The two kinds of cells performs a pipeline operation to complete the operations of the two cells at the same time. A CGH calculator to compute the hole hologram for a light source is structured by arranging the two kinds of cells. Results from simulation showed that the maximum operation frequency is about 215MHz. So, experiments are performed by setting this frequency and the same environments as the method showing the best performance. As the results, the proposed one could complete the computation of 81.75 CGH frames per second, while the previous method computes 62.9 CGH frames per second.

In-situ Thermally Curable Hyper-branched 10H-butylphenothiazine

  • Jo, Mi-Young;Lim, Youn-Hee;Ahn, Byung-Hyun;Lee, Gun-Dae;Kim, Joo-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.492-498
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    • 2012
  • A hyper branched 10-butylphenothiazine with in-situ thermally curable methacrylate (1,3,5-tris-[$\{$10-Butyl-3-(4-(2-methyl-acryloyloxy)-phenyl)-7-yl-10H-phenothiazine$\}$]-benzene, (tris-PTMA)) was synthesized successfully. From the TGA thermogram of tris-PTMA was thermally stable up to $336^{\circ}C$. In the first heating scan of DSC thermogram, tris-PTMA showed glass transition temperature (Tg) at $140^{\circ}C$ and broad endothermic process in the region of $144-179^{\circ}C$, which is thermally curing temperature. In the second heating process, $T_g$ exhibited at $158.7^{\circ}C$ and endothermic process was not observed. Thermally cured tris-PTMA showed no big change in the UV-visible spectrum after washing with organic solvent such as methylene chloride, chloroform, toluene, indicating that thermally cured film was very good solvent resistance. Thermally cured tris-PTMA was electrochemically stable and the HOMO energy level of tris-PTMA was -5.54 eV. The maximum luminance efficiency of double layer structured polymer light-emitting diode based on in-situ thermally cured tris-PTMA was 0.685 cd/A at 16.0 V, which was higher than that of the device without thermally cured tris-PTMA (0.348 cd/A at 15.0 V).

Development of Two-color Radiation Thermometer for Harsh Environments

  • Mohammed, Mohammed Ali Alshaikh;Kim, Ki-Seong
    • Journal of ILASS-Korea
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    • v.21 no.4
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    • pp.184-194
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    • 2016
  • Many industrial processes require reliable temperature measurements in harsh environments with high temperature, dust, humidity, and pressure. However, commercially-available conventional temperature measurement devices are not suitable for use in such conditions. This study thus proposes a reliable, durable two-color radiation thermometer (RT) for harsh environments that was developed by selecting the appropriate components, designing a suitable mechanical structure, and compensating environmental factors such as absorption by particles and gases. The two-color RT has a simple, compactly-designed probe with a well-structured data acquisition system combined with efficient LabVIEW-based code. As a result, the RT can measure the temperature in real time, ranging from 300 to $900^{\circ}C$ in extremely harsh environments, such as that above the burden zone of a blast furnace. The error in the temperature measurements taken with the proposed two-color RT compared to that obtained using K-type thermocouple readouts was within 6.1 to $1.4^{\circ}C$ at a temperature range from 200 to $700^{\circ}C$. The effects of absorption by gases including $CO_2$, CO and $H_2O$ and the scattering by fine particles were calculated to find the transmittance of the two wavelength bands of operation through the path between the measured burden surface and the two-color probe. This method is applied to determine the transmittance of the short and long wavelength bands to be 0.31 and 0.51, respectively. Accordingly, the signals that were measured were corrected, and the true burden surface temperature was calculated. The proposed two-color RT and the correction method can be applied to measure temperatures in harsh environments where light-absorbing gases and scattering particles exist and optical components can be contaminated.