• Korean Journal of Cognitive Science
• /
• v.15 no.4
• /
• pp.1-14
• /
• 2004

When two objects are tying in the same visual direction there occurs abrupt depth change between two objects, which is against the assumption of the computational model for stereopsis on the surfaces in a natural scene. For this reason, this stimulus configuration is popularly used in the studies for the effectiveness of the constraints employed in the computational model. Contrary to the results from two nails (or objects) tying in the same visual direction, the two different surfaces from random-dot stereogram (RDS) in the same situation can be seen simultaneously in the different depth. The seemingly contradictory results between two situations my reflect the different strategies imposed by binocular mechanism for each situation during binocular matching process. Otherwise, the surfaces tying in the same visual direction is not equivalent situation to two objects tying in the same visual direction with regards to matching process. In order to examine above possibilities, the stereoscopic depth of the surface was measured after manipulating the visual direction of the surface elements. The visual direction of each dot pair from different surfaces in RDS (in Experiment 1) or the visual direction of line (hawing rectangle with regard to that of the vertical line (in Experiment 2) was manipulated. The stereoscopic depth of the surface was found to be varied depending on visual direction of the surface elements in both RDS and line hawing stimulus. Similar to the results from two nails situation depth of the surface was greatly reduced when each surface element was tying in the same visual direction as that of the other surface element or the other object. These results suggest that binocular mechanism imposes no different strategy in resolving correspondence problem in both two objects and two surfaces situation. And the results were discussed in the context of usefulness of the constraints employed in the computational model for stereopsis.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.25 no.4
• /
• pp.427-435
• /
• 2023

Changes in flowering time due to weather fluctuations impact plant growth and ecosystem dynamics. Accurate prediction of flowering timing is crucial for effective forest ecosystem management. This study uses a process-based model to predict flowering timing in 2023 for five major tree species in Korean forests. Models are developed based on nine years (2009-2017) of flowering data for Abeliophyllum distichum, Robinia pseudoacacia, Rhododendron schlippenbachii, Rhododendron yedoense f. poukhanense, and Sorbus commixta, distributed across 28 regions in the country, including mountains. Weather data from the Automatic Mountain Meteorology Observation System (AMOS) and the Korea Meteorological Administration (KMA) are utilized as inputs for the models. The Single Triangle Degree Days (STDD) and Growing Degree Days (GDD) models, known for their superior performance, are employed to predict flowering dates. Daily temperature readings at a 1 km spatial resolution are obtained by merging AMOS and KMA data. To improve prediction accuracy nationwide, random forest machine learning is used to generate region-specific correction coefficients. Applying these coefficients results in minimal prediction errors, particularly for Abeliophyllum distichum, Robinia pseudoacacia, and Rhododendron schlippenbachii, with root mean square errors (RMSEs) of 1.2, 0.6, and 1.2 days, respectively. Model performance is evaluated using ten random sampling tests per species, selecting the model with the highest R². The models with applied correction coefficients achieve R² values ranging from 0.07 to 0.7, except for Sorbus commixta, and exhibit a final explanatory power of 0.75-0.9. This study provides valuable insights into seasonal changes in plant phenology, aiding in identifying honey harvesting seasons affected by abnormal weather conditions, such as those of Robinia pseudoacacia. Detailed information on flowering timing for various plant species and regions enhances understanding of the climate-plant phenology relationship.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.38 no.5
• /
• pp.329-337
• /
• 2001

It has been known that the leakage current in the low field region consists of the dielectric relaxation current and intrinsic leakage current, which cause the charge loss in dynamic random access memory (DRAM) storage capacitor using (Ba,Sr)TiO$_{3}$ (BST) thin film. Especially, the dielectric relaxation current should be seriously considered since its magnitude is much larger than that of the intrinsic leakage current in giga-bit DRAM operation voltage (~IY). In this study, thermally stimulated current (TSC) measurement was at first applied to investigate the activation energy of traps and relative evaluation of the density of traps according to process change. And, through comparing TSC to early methods of I-V or I-t measurement and analyzing, we identify the origin of the dielectric relaxation current and investigate the reliability of TSC measurement. First, the polarization condition such as electric field, time, temperature and heating rate was investigated for reliable TSC measurement. From the TSC measurement, the energy level of traps in the BST thin film has been investigated and evaluated to be 0.20($\pm$0.01) eV and 0.45($\pm$0.02) eV. Based on the TSC measurement results before and after rapid thermal annealing (RTA) process, oxygen vacancy is concluded to be the origin of the traps. TSC characteristics with thermal annealing in the MIM BST capacitor have shown the same trends with the current-voltage (I-V) and current-time (I-t) characteristics. This means that the TSC measurement is one of the effective methods to characterize the traps in the BST thin film.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.12
• /
• pp.2329-2334
• /
• 2006

In this paper, we proposed a method complementing failure of combining DNA fragments, defect of conventional contig assembly programs. In the proposed method, very long DNA sequence data are made into a prototype of fragment of about 700 bases that can be analyzed by automatic sequence analyzer at one time, and then matching ratio is calculated by comparing a standard prototype with 3 fragmented clones of about 700 bases generated by the PCR method. In this process, the time for calculation of matching ratio is reduced by Compute Agreement algorithm. Two candidates of combined fragments of every prototype are extracted by the degree of overlapping of calculated fragment pairs, and then degree of combination is decided using a fuzzy reasoning method that utilizes the matching ratios of each extracted fragment, and A, C, G, T membership degrees of each DNA sequence, and previous frequencies of each A, C, G, T. In this paper. DNA sequence combination is completed by the iteration of the process to combine decided optimal test fragments until no fragment remains. For the experiments, fragments or about 700 bases were generated from each sequence of 10,000 bases and 100,000 bases extracted from 'PCC6803', complete protein genome. From the experiments by applying random notations on these fragments, we could see that the proposed method was faster than FAP program, and combination failure, defect of conventional contig assembly programs, did not occur.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.14 no.3
• /
• pp.669-678
• /
• 1994

The BOD removal characteristics of submerged biofilters filled with three kinds of filter media respectively were experimentally examined with constant temperature, pH value and variable BOD loading and recirculation ratio. Obtained results are as follows; 1. The BOD removal ratio decreases with the increasing $BOD_5$ volumetric loading rate, and the loading rate for the BOD removal over 90% is lower thean $1.6kg{\cdot}BOD_5/m^3{\cdot}d$ for the plastic media of Netring and cubic wire meshes. This is a much large value than $0.3{\sim}0.8kg{\cdot}BOD_5/m^3{\cdot}d$ for conventional activated sludge process. The required submerged biofilter volume is found to be much samller than that of conventional activated sludge process. 2. The decreasing order of BOD removal is Netring (random plastic media), cubic wire meshes (plastic module), and then gravel (stone media). This is mainly due to the media characteristics such as void ratio, specific surface area and media shapes. 3. The $BOD_5$ removal rate increases with the recircuration ration, but the rate of increases becomes samaller as the recirculation ratio increases over 20. When $BOD_5$ loading is $1.8kg{\cdot}BOD_5/m^3{\cdot}d$, the required recirculation rationto obtain 90% $BOD_5$ removal is about 20 for Netring and it was about 30 for cubic wire meshes. 4. Reynold's Number increases with recirculation ratio, and the Reynold's Numbers corresponding to the recircuration ratio of 10~50 are less than 52, showing laminar up flows in the filter. The settled and effluent sludges increase with increase of Reynol's Number, and there are the definite Reynold's Numbers at which the settling sludge concentrations become nearly constant respectively in each filters. 5. In this submerged biofilter system, small volume of sludge hopper can be substituted for a separated settling tank.

• The Journal of the Korea Contents Association
• /
• v.14 no.2
• /
• pp.181-191
• /
• 2014

In the past, making IR photography needed somewhat complicated process, so its application fields were limited. However, it has become easy to make IR photography with advanced digital technology, so it is expected that the fields of IR photography and existing limit due to difficult making process will be expanded. Therefore, in this study, it is decided that the need of IR standard chart which allows us to manage exposure and tone of IR photography for scientific purpose will increase. Two methods were used to make IR standard chart. First method is to use aluminum. When aluminum has oxide coating through anodic oxidation, it has high durability, corrosion resistance and heat resistance. Also, IR reflectance of aluminum can be controlled in some degree depending on the thickness of oxide coating. Second method is to use pigments. Yellow 10P150 pigment is used for the brightest patch. This pigment is appropriate in this study due to high heat resistance and IR reflectance. Carbon black is used for the darkest patch. Carbon black absorbs much IR, and its color is not faded by any source of light. IR reflectance is adjusted elaborately by mixing two pigments. Finally, 6 patches are selected with consideration for actual IR reflectance of patches. As a result, IR reflectance of random subjects can be known approximately and IR photographs can have appropriate contrast with the IR standard chart.

• The Journal of the Korea Contents Association
• /
• v.15 no.1
• /
• pp.482-494
• /
• 2015

The purpose of this study was to investigate a total of 800 visitors of those who had enjoyed "2013 Cheonan Heung-taryeong dance Festival". In order to achieve the research goal, the study conducted the questionnaire in the venue of the festival and selected the research subjects at random. With certain standards to measure the social quality, the process quality and the physical quality as in the service quality determined, the study looked into how each of the extracted factors would influence the service quality in general. The study also discussed effects of the general service quality both on the satisfaction and the re-visit intention of the festival visitors. According to the results from the analysis, 1) the social quality factors (the cultural effect and the image effect), 2) the process quality factors (the visitor-focused service and the food and souvenir), 3) the physical quality factors (the convenience in connection with the visitors' enjoying the festival and the facility arrangement) and 4) the general service quality of the festival were confirmed to affect the visitors' satisfaction. 5) The study also learned that how much the visitors of the festival have been satisfied with the event would have an effect on the visitors' intention to re-visit. After all, the study came up with every statistically significant difference in relation to the effects of the service quality on the satisfaction and the re-visit intention of the visitors in the festival.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.42 no.6 s.336
• /
• pp.31-38
• /
• 2005

In this paper, we proposed an optical security system based on a gray-image exclusive-OR encryption using multi-phase separation and phase-wrapping method. For encryption, a gray image is sliced into binary images, which have the same pixel value, and these images are encrypted by modified XOR rules with binary random images. The XORed images and the binary images respectively combined and converted into full phase images, called an encrypted image and a key image. For decryption, when the encrypted image and key image are used as inputs on optical elements, Practically due to limited controllability of phase range in optical elements, the original gray image cannot be efficiently reconstructed by these optical elements. Therefore, by decreasing the phase ranges of the encrypted image and key image using a phase-wrapping method and separating these images into low-level phase images using multi-phase separation, the gray image can be reconstructed by optical elements which have limited control range. The decrytion process is simply implemented by interfering a multiplication result of encrypted image and key image with reference light. The validity of proposed scheme is verified and the effects, which are caused by phase limitation in decryption process, is analyzed by using computer simulations.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.363-363
• /
• 2014

Ruthenium (Ru) has attractive material properties due to its promising characteristics such as a low resistivity ($7.1{\mu}{\Omega}{\cdot}cm$ in the bulk), a high work function of 4.7 eV, and feasibility for the dry etch process. These properties make Ru films appropriate for various applications in the state-of-art semiconductor device technologies. Thus, it has been widely investigated as an electrode for capacitor in the dynamic random access memory (DRAM), a metal gate for metal-oxide semiconductor field effect transistor (MOSFET), and a seed layer for Cu metallization. Due to the continuous shrinkage of microelectronic devices, better deposition processes for Ru thin films are critically required with excellent step coverages in high aspect ratio (AR) structures. In these respects, atomic layer deposition (ALD) is a viable solution for preparing Ru thin films because it enables atomic-scale control of the film thickness with excellent conformality. A recent investigation reported that the nucleation of ALD-Ru film was enhanced considerably by using a zero-valent metallorganic precursor, compared to the utilization of precursors with higher metal valences. In this study, we will present our research results on the synthesis and characterization of novel ruthenium complexes. The ruthenium compounds were easy synthesized by the reaction of ruthenium halide with appropriate organic ligands in protic solvent, and characterized by NMR, elemental analysis and thermogravimetric analysis. The molecular structures of the complexes were studied by single crystal diffraction. ALD of Ru film was demonstrated using the new Ru metallorganic precursor and O2 as the Ru source and reactant, respectively, at the deposition temperatures of $300-350^{\circ}C$. Self-limited reaction behavior was observed as increasing Ru precursor and O2 pulse time, suggesting that newly developed Ru precursor is applicable for ALD process. Detailed discussions on the chemical and structural properties of Ru thin films as well as its growth behavior using new Ru precursor will be also presented.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.3
• /
• pp.16-20
• /
• 2018

Steel Fiber reinforced self-compacting concrete (SFRSCC) has been widely used in a number of structures, such as ordinary civil infrastructures, sky scrapers, nuclear power plants, hospitals, dams, channels and etc. Thanks to its short and discrete reinforcing fibers, its performance, including tensile strength, ductility, toughness and flexural strength gets much better in comparison with ordinary self-compacting concrete (SCC) without any reinforcing fibers. Despite all these aforementioned advantages of SFRSCC, its performance highly depends on fiber's orientation. In case of short discrete fibers, the orientation of fibers is completely random and cannot be controlled during pumping process. If fibers distribution inside hardened state concrete are randomly distributed, it leads to less resistance potential of concrete element, especially in terms of flexural and tensile strength. The maximum expected strength may not be achieved. Therefore, fiber alignment has been considered as one of the important factors in SFRSCC. To address this issue, this study investigates the effects of concrete matrix's density and inlet velocity on fiber alignment during the pumping process using a finite element method.