• Agricultural and Biosystems Engineering
• /
• v.4 no.1
• /
• pp.8-15
• /
• 2003

In Korea, quality evaluation of dried oak mushrooms are done first by classifying them into more than 10 different categories based on the state of opening of the cap, surface pattern, and colors. And mushrooms of each category are further classified into 3 or 4 groups based on its shape and size, resulting into total 30 to 40 different grades. Quality evaluation and sorting based on the external visual features are usually done manually. Since visual features of mushroom affecting quality grades are distributed over the entire surface of the mushroom, both front (cap) and back (stem and gill) surfaces should be inspected thoroughly. In fact, it is almost impossible for human to inspect every mushroom, especially when they are fed continuously via conveyor. In this paper, considering real time on-line system implementation, image processing algorithms utilizing artificial neural network have been developed for the quality grading of a mushroom. The neural network based image processing utilized the raw gray value image of fed mushrooms captured by the camera without any complex image processing such as feature enhancement and extraction to identify the feeding state and to grade the quality of a mushroom. Developed algorithms were implemented to the prototype on-line grading and sorting system. The prototype was developed to simplify the system requirement and the overall mechanism. The system was composed of automatic devices for mushroom feeding and handling, a set of computer vision system with lighting chamber, one chip microprocessor based controller, and pneumatic actuators. The proposed grading scheme was tested using the prototype. Network training for the feeding state recognition and grading was done using static images. 200 samples (20 grade levels and 10 per each grade) were used for training. 300 samples (20 grade levels and 15 per each grade) were used to validate the trained network. By changing orientation of each sample, 600 data sets were made for the test and the trained network showed around 91 % of the grading accuracy. Though image processing itself required approximately less than 0.3 second depending on a mushroom, because of the actuating device and control response, average 0.6 to 0.7 second was required for grading and sorting of a mushroom resulting into the processing capability of 5,000/hr to 6,000/hr.

• Journal of Energy Engineering
• /
• v.24 no.2
• /
• pp.120-128
• /
• 2015

This study reports the combustion characteristics, such as burner temperature and the concentration of exhausted gas ($O_2$, $CO_x$, $NO_x$) due to the different types and pitches of the fuel supply feeder of the wood pellet boiler. The 1st grade wood pellets composed of mainly larch have been used for the experiment. In case of using the spring feeder, mean temperature of burner was approximately $821.76^{\circ}C$, and the mean concentration of oxygen, carbon monoxide, carbon dioxide and nitrogen oxide were approximately 8.88%, 93.35ppm, 12.15% and 139.83 ppm, respectively. The test result with the spring feeder was shown to approach the condition of complete combustion compared to that of a screw feeder and were in good agreement with authentication judgement standard. Furthermore, the combustion efficiency was improved according to the growth of screw pitch. The control of air flow rate from the blower and ventilator is needed to achieve the complete combustion.

• Journal of Chest Surgery
• /
• v.35 no.2
• /
• pp.144-148
• /
• 2002

The present study was done to determine the efficacy and safety of varicose vein removal using a minimally invasive, powered vein-extracting device with cutaneous transillumination and tumescent anesthesia techniques and then compared this to a retrospective group of conventional phlebectomy operations. There were 133 limbs in 104 patients(72 women, 32 men) treated with the use of the vein extractor aided by transcutaneous illumination. The hydrodissection was performed with Trivex™ Irrigated illuminator(Smith & Nephe $w^{ R}$) system using normal saline after the 2~3mm sized skin incision. Varicose clusters were extracted by the use of TriveTM esector(Smith & Nephe $w^{ R}$) system under transillumination. After the varisoce vein extraction, the operation area was compressed with surgical pad for bleeding control. The complication rate was 3.84% The mean number of incisions was 3.24 and mean operative time per limb was 65.9 minutes. The mean hospitalization was 1.86 days. The varicose vein extraction using transilluminated powered phlebectomy(TIPP) is a safe, efficacious and cosmetically satisfactory method. The procedure decreases the operating time and the number of incisions required to remove varicose clusters. Further evaluation and long term follow up will be necessary to determine the recurrence rate and long termcomplications.to determine the recurrence rate and long termcomplications.

• Journal of radiological science and technology
• /
• v.18 no.2
• /
• pp.87-102
• /
• 1995

The education of radiologic technology began in the regular institute of higher education in Korea in 1963. Up to now from then, our education to bring up the radiologic technologists has developed greatly in quality and quantity, and now departments of radio-technology are founded in the 16 junior colleges in March, 1995. This study was done to verify the necessity and propriety to reform the education system of radiologic technology which was run as two or three year system of college curriculum for 32 years since 1963, and to search for the method to reform in the future. We got the following results from this research. 1. In the survey, on the desirable education year for radiologic technologists, 63.9 % of professors of department of radio-technology and 63.0 % of radiologic technologists chose the 4 year system, 27.9 % of professors and 34.6 % of radiologic technologists chose the 4 year system added to graduate school. 2. In the survey, on the future development of radiologic equipments and technique, 67.2 % of professors of department of radiologic technology and 86.4 % of radiologic technologists have a view of "revolutional development". Also, on the future tasks or roles of radiologic technologists 95.1% of professors and 94.9% of radiologic technologists have a view that "They will increase". 3. On the necessity of extension of education year to 4 years from 3 years, the factor is that development of medical technique and machinery and tools, advance of qualification of radiologic technologists, enlargement and specialization of the business of the radiologic technologists, ballance of education year with other medical sciences, international competitive power and cooperation of radiologic technology, and education continuation of the graduates of department of radiologic technology. 4. They suggested that in the 4 year curriculum of department of radiologic technology, clinical medicine, quality control of radiation and radiologic equipment, related subjects to the radiologic application and computer application should be enforced and clinical practice should be extended more. 5. On the device to found the 4 year college curriculum of radiologic technology, they suggested that first, 4 year curriculum should be founded through the variety of educational year, secondly, department of radiologic technology should be founded in the 4 year health sciences college, thirdly, educational continuation of the radiologic technologists should be systematized on the basis of life-long education.

• Nuclear Medicine and Molecular Imaging
• /
• v.43 no.4
• /
• pp.344-351
• /
• 2009

Purpose: Optical imaging is providing great advance and improvement in genetic and molecular imaging of animals and humans. Optical imaging system consists of optical imaging devices, which carry out major function for monitoring, tracing, and imaging in most of molecular in-vivo researches. In bio-luminescent imaging, small animals containing luciferase gene locally irradiate light, and emitted photons transmitted through skin of the small animals are imaged by using a high sensitive charged coupled device (CCD) camera. In this paper, we introduced optical imaging system for the image acquisition of bio-luminescent signals emitted from small animals. Materials and Methods: In the system, Nikon lens and four LED light sources were mounted at the inside of a dark box. A cooled CCD camera equipped with a control module was used. Results: We tested the performance of the optical imaging system using effendorf tube and light emitting bacteria which injected intravenously into CT26 tumor bearing nude mouse. The performance of implemented optical imaging system for bio-luminescence imaging was demonstrated and the feasibility of the system in small animal imaging application was proved. Conclusion: We anticipate this system could be a useful tool for the molecular imaging of small animals adaptable for various experimental conditions in future.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.239-240
• /
• 2012

With advancements in semiconductor device technologies, manufacturing processes are getting more complex and it became more difficult to maintain tighter process control. As the number of processing step increased for fabricating complex chip structure, potential fault inducing factors are prevail and their allowable margins are continuously reduced. Therefore, one of the key to success in semiconductor manufacturing is highly accurate and fast fault detection and classification at each stage to reduce any undesired variation and identify the cause of the fault. Sensors in the equipment are used to monitor the state of the process. The idea is that whenever there is a fault in the process, it appears as some variation in the output from any of the sensors monitoring the process. These sensors may refer to information about pressure, RF power or gas flow and etc. in the equipment. By relating the data from these sensors to the process condition, any abnormality in the process can be identified, but it still holds some degree of certainty. Our hypothesis in this research is to capture the features of equipment condition data from healthy process library. We can use the health data as a reference for upcoming processes and this is made possible by mathematically modeling of the acquired data. In this work we demonstrate the use of recurrent neural network (RNN) has been used. RNN is a dynamic neural network that makes the output as a function of previous inputs. In our case we have etch equipment tool set data, consisting of 22 parameters and 9 runs. This data was first synchronized using the Dynamic Time Warping (DTW) algorithm. The synchronized data from the sensors in the form of time series is then provided to RNN which trains and restructures itself according to the input and then predicts a value, one step ahead in time, which depends on the past values of data. Eight runs of process data were used to train the network, while in order to check the performance of the network, one run was used as a test input. Next, a mean squared error based probability generating function was used to assign probability of fault in each parameter by comparing the predicted and actual values of the data. In the future we will make use of the Bayesian Networks to classify the detected faults. Bayesian Networks use directed acyclic graphs that relate different parameters through their conditional dependencies in order to find inference among them. The relationships between parameters from the data will be used to generate the structure of Bayesian Network and then posterior probability of different faults will be calculated using inference algorithms.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.27-27
• /
• 2011

For the design of real applicable molecular devices, current-voltage properties through molecular nanostructures such as metal-molecule-metal junctions (molecular junctions) have been studied extensively. In thiolate monolayers on the gold electrode, the chemical bonding of sulfur to gold and the van der Waals interactions between the alkyl chains of neighboring molecules are important factors in the formation of well-defined monolayers and in the control of the electron transport rate. Charge transport through the molecular junctions depends significantly on the energy levels of molecules relative to the Fermi levels of the contacts and the electronic structure of the molecule. It is important to understand the interfacial electron transport in accordance with the increased film thickness of alkyl chains that are known as an insulating layer, but are required for molecular device fabrication. Thiol-tethered RuII terpyridine complexes were synthesized for a voltage-driven molecular switch and used to understand the switch-on mechanism of the molecular switches of single metal complexes in the solid-state molecular junction in a vacuum. Electrochemical voltammetry and current-voltage (I-V) characteristics are measured to elucidate electron transport processes in the bistable conducting states of single molecular junctions of a molecular switch, Ru(II) terpyridine complexes. (1) On the basis of the Ru-centered electrochemical reaction data, the electron transport rate increases in the mixed self-assembled monolayer (SAM) of Ru(II) terpyridine complexes, indicating strong electronic coupling between the redox center and the substrate, along the molecules. (2) In a low-conducting state before switch-on, I-V characteristics are fitted to a direct tunneling model, and the estimated tunneling decay constant across the Ru(II) terpyridine complex is found to be smaller than that of alkanethiol. (3) The threshold voltages for the switch-on from low- to high-conducting states are identical, corresponding to the electron affinity of the molecules. (4) A high-conducting state after switch-on remains in the reverse voltage sweep, and a linear relationship of the current to the voltage is obtained. These results reveal electron transport paths via the redox centers of the Ru(II) terpyridine complexes, a molecular switch.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.288-289
• /
• 2011

Indium Tin Oxide (ITO) is a typical highly Transparent Conductive Oxide (TCO) currently used as a transparent electrode material. Most widely used deposition method is the sputtering process for ITO film deposition because it has a high deposition rate, allows accurate control of the film thickness and easy deposition process and high electrical/optical properties. However, to apply high quality ITO thin film in a flexible microelectronic device using a plastic substrate, conventional DC magnetron sputtering (DMS) processed ITO thin film is not suitable because it needs a high temperature thermal annealing process to obtain high optical transmittance and low resistivity, while the generally plastic substrates has low glass transition temperatures. In the room temperature sputtering process, the electrical property degradation of ITO thin film is caused by negative oxygen ions effect. This high energy negative oxygen ions(about over 100eV) can be critical physical bombardment damages against the formation of the ITO thin film, and this damage does not recover in the room temperature process that does not offer thermal annealing. Hence new ITO deposition process that can provide the high electrical/optical properties of the ITO film at room temperature is needed. To solve these limitations we develop the Magnetic Field Shielded Sputtering (MFSS) system. The MFSS is based on DMS and it has the plasma limiter, which compose the permanent magnet array (Fig.1). During the ITO thin film deposition in the MFSS process, the electrons in the plasma are trapped by the magnetic field at the plasma limiters. The plasma limiter, which has a negative potential in the MFSS process, prevents to the damage by negative oxygen ions bombardment, and increases the heat(-) up effect by the Ar ions in the bulk plasma. Fig. 2. shows the electrical properties of the MFSS ITO thin film and DMS ITO thin film at room temperature. With the increase of the sputtering pressure, the resistivity of DMS ITO increases. On the other hand, the resistivity of the MFSS ITO slightly increases and becomes lower than that of the DMS ITO at all sputtering pressures. The lowest resistivity of the DMS ITO is $1.0{\times}10-3{\Omega}{\cdot}cm$ and that of the MFSS ITO is $4.5{\times}10-4{\Omega}{\cdot}cm$. This resistivity difference is caused by the carrier mobility. The carrier mobility of the MFSS ITO is 40 $cm^2/V{\cdot}s$, which is significantly higher than that of the DMS ITO (10 $cm^2/V{\cdot}s$). The low resistivity and high carrier mobility of the MFSS ITO are due to the magnetic field shielded effect. In addition, although not shown in this paper, the roughness of the MFSS ITO thin film is lower than that of the DMS ITO thin film, and TEM, XRD and XPS analysis of the MFSS ITO show the nano-crystalline structure. As a result, the MFSS process can effectively prevent to the high energy negative oxygen ions bombardment and supply activation energies by accelerating Ar ions in the plasma; therefore, high quality ITO can be deposited at room temperature.

• Journal of Internet Computing and Services
• /
• v.14 no.5
• /
• pp.27-38
• /
• 2013

Currently a number of managers exist to manage heterogeneous networks, in this situation, the NETCONF protocol for efficient network management has been proposed as a new protocol. However, the standard NETCONF protocol stack continuous improvement since the establishment but in four layers still have some problems. Especially in situations where there are multiple administrators, problems are more highlighted in operation layer. In this paper, we focus on these issues and the Operation layer has improved the efficiency and flexibility of operations among NETCONF four layers. Additionally, for the inefficiency of updates improved the device settings based on improved operation techniques. In addition, standard protocol NETCONF did not proposed content layer data structure and we propose standard technique of content layer that can generate configuration structure of devices. Improved the three techniques are applied appropriately to the NETCONF, the proposed method and the existing NETCONF was performed experiment to compare with experimental four factors. Compare key factor are four kind as maintaining the probability of network function, the reaction performance about command, the number of control packets, performance of data creation in content layer. Such factors after performing the experiment, the proposed method in this paper is superior to the existing NETCONF and there was confirmed by analysis Experimental results.

• Journal of the Korean Geotechnical Society
• /
• v.31 no.6
• /
• pp.71-82
• /
• 2015

Recently, due to the expansion of urban infrastructure for the citizen convenience, the shield tunnel construction has increased considering the civil complaints minimization and construction stability. Most shield tunnels are designed based on the assumption of the undrained condition that underground water does not inflow, but they are operated in the field as drained tunnels with drainage facility to drain underground water. Therefore, the drained condition needs to be considered in the shield tunnel design. It is also necessary to consider the weathered granite soil that is widely distributed throughout the country and consequently is encountered in most of construction sites. In this paper, the model test which can control total stress and pore water pressure and simulate the underground tunnel located in the weathered granite soil below ground water level is conducted. Total stress, pore water pressure and an inflow water into an inner pipe were measured using the testing device. Test results showed that the total stress in a drained condition was lower than in an undrained condition because pore water pressure decreased in a drained condition and an inflow water into an inner pipe was proportional to the loading stress in a drained condition. As a result, if a drained condition is considered in the shield tunnel design, the more economical design can be expected because of the stress reduction of the lining.