• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.4
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• pp.331-335
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• 2020

In this study, through the accumulated technologies such as real-time monitoring of power consumption using power line communication (PLC) method, power control, and automatic blocking of standby power, to commercialize them, we developed the hardware design, algorithm, protocol and module along with data transmission using PLC. We conducted the study to develop advanced products. We also proposed cloud-based smart outlet products with a novel type of outlet. These products can measure the internal power consumption through the H/W modules and the modules that control the power of household appliances connected to the smart outlets and smart plugs. Subsequently, they transmit the measurements to the energy saving system server via a communication module. This system can control the terminal device connected to the Gateway (G/W) server through a mobile phone. This will allow the customer to check the power consumption of the building at any given time, to turn the terminal on/off, and to maximize the energy efficiency during the construction of new apartments or multi-family housing in an area.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.57-64
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• 2020

Video surveillance is consists of cameras, transmission devices, storage and playback devices, and is used for crime prevention and disaster monitoring. Recently, it has been spreading to a wide variety of fields, and has developed into an intelligent video surveillance system that can automatically recognize or track characteristic objects of people and things. The purpose of this study was to investigate the cases of video surveillance service applying the latest technology by dividing it into the home, public, and private sectors. also this study tried to investigate and research what advantage it brings from a business perspective. By looking at the cases introduced in this study, it was confirmed that the viedo security service is developing intelligently, such as excellent compatibility with CCTV, multiple video surveillance, CCTV screen motion detection, and alarm through automatic analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.422-429
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• 2022

In this paper, the intermediate frequency transmission signal level between the network system-based baseband and RF unit consisting of multi-channel airborne relay devices and a lot of mission devices, which are currently undergoing technology development tasks, is kept constant at the reference signal level. Considering the other party's receiving input range, despite changes in the short-range long-range wireless communication environment, it presents a multi-link protection and MLP-A algorithm that allows signals to be transmitted stably and reliably through signal detection automatic gain control, and experiments and analysis considering short-distance and long-distance wireless environments were performed by designing, manufacturing, and implementing RF units to which MLP-A algorithms were applied, and applying distance calculation equations to the configuration of multiple air movements and verification networks. Through this, it was confirmed that a stable and reliable RF communication system can be operated.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.538-548
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• 2016

The purpose of this study is to identify the possibility of effective tuning works, understand the characteristics of tuning engine, and analyse the basic data of engine tuning inspection corresponding to the safe operation and environment of a driving gasoline car. The effects of tuning on the characteristics of performance and exhaust emissions under a wide range of engine speeds are experimentally investigated by the actual driving car with a four-cycle, four-cylinder DOHC, turbo-intercooler, water-cooled gasoline engine operating at four types of non-tuning, tuning 1, 2 and 3. The tuning parts in the gasoline engine are the intake manifold, intake pipe and air filter. In the experiment, the output, torque and air-fuel ratio of the five-speed automatic transmission vehicles were measured at the chassis dynamometer(Dynojet 224xLC) with one person on board. The exhaust emissions of $NO_X$, THC, CO, $O_2$ and $CO_2$, and excess air ratio(${\lambda}$) at the other chassis dynamometer(DASAN-MD-ASM-97-KR-HD) were also measured by the idle/constant-speed mode(ASM2525 mode) test method. It is found that the actual air-fuel ratios of non-tuning and tuning engines were shown to be lower than the stoichiometric air-fuel ratio with increasing engine speed, and the actual air-fuel ratio of non-tuning engine was slightly higher than those of tuning engines when the engine speed is more than 4000 rpm. The output was significantly increased by the tuning whereby the maximum output of tuning engine was more increased to approximately 117.64% than that of non-tuning engine. In addition, CO, THC and $NO_X$ emissions of non-tuning and tuning engines measured by the constant-speed test mode were all satisfied with the inspection standards. CO emission was increased, while THC and $NO_X$ emissions were reduced by tuning.

• Publications of The Korean Astronomical Society
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• v.36 no.3
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• pp.65-78
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• 2021

Jagyeokru, an automatic striking water clock described in the Sejong Sillok (Veritable Records of King Sejong) is essentially composed of a water quantity control device and a time-signal device, with the former controlling the amount or the flow rate of water and the latter automatically informing the time based on the former. What connects these two parts is a signal generating device or a power transmission device called the 'Jujeon' system, which includes a copper rod on the float and ball-racked scheduled plates. The copper products excavated under Gongpyeong-dong in Seoul include a lot of broken plate pieces and cylinder-like devices. If some plate pieces are put together, a large square plate with circular holes located in a zigzag can be completed, and at the upper right of it is carved 'the first scheduled plate (一箭).' Cylinder-like devices generally 3.8 cm in diameter are able to release a ball, and have a ginkgo leaf-like screen fixed on the inner axis and a bird-shaped hook of which the leg fixes another axis and the beak attaches to the leaf side. The lateral view of this cylinder-like device appears like a trapezoid and mounts an iron ball. The function of releasing a ball agrees with the description of Borugak Pavilion, where Jagyeokru was installed, written by Kim Don (1385 ~ 1440). The other accounts of Borugak Pavilion's and Heumgyeonggak Pavilion's water clocks describe these copper plates and ball releasing devices as the 'Jujeon' system. According to the description of Borugak Pavilion, a square wooden column has copper plates on the left and right sides the same height as the column, and the left copper plate has 12 drilled holes to keep the time of a 12 double-hours. Meanwhile, the right plate has 25 holes which represent seasonal night 5-hours (Kyeong) and their 5-subhours (Jeom), not 12 hours. There are 11 scheduled plates for seasonal night 5-hours made with copper, which are made to be attached or detached as the season. In accordance with Nujutongui (manual for the operation of the yardstick for the clepsydra), the first scheduled plate for the night is used from the winter solstice (冬至) to 2 days after Daehan (大寒), and from 4 days before Soseol (小雪) to a day before the winter solstice. Besides the first scheduled plate, we confirm discovering a third scheduled plate and a sixth scheduled plate among the excavated copper materials based on the spacing between holes. On the other hand, the width of the scheduled plate is different for these artifacts, measured as 144 mm compared to the description of the Borugak Pavilion, which is recorded as 51 mm. From this perspective, they may be the scheduled plates for the Heumgyeonggak Ongru made in 1438 (or 1554) or for the new Fortress Pavilion installed in Changdeokgung palace completed in 1536 (the 31^st year of the reign of King Jungjong) in the early Joseon dynasty. This study presents the concept of the scheduled plates described in the literature, including their new operating mechanism. In addition, a detailed model of 11 scheduled plates is designed from the records and on the excavated relics. It is expected that this study will aid in efforts to restore and reconstruct the automatic water clocks of the early Joseon dynasty.

• Journal of Veterinary Clinics
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• v.33 no.2
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• pp.107-112
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• 2016

The objective of this study was to determine potential contributing factors associated with biosecurity level of farrow-to-finish pig farms and to develop a classification tree model to explore how these factors related to each other based on prediction model. To this end, the author analyzed data (n = 193) extracted from a cross-sectional study of 344 farrow-to-finish farms which was conducted between March and September 2014 aimed to explore swine disease status at farm level. Standardized questionnaires with information about basic demographical data and management practices were collected in each farm by on-site visit of trained veterinarians. For the classification of the data sets regarding biosecurity level as a dependent variable and predictor variables, Chi-squared Automatic Interaction Detection (CHAID) algorithm was applied for modeling classification tree. The statistics of misclassification risk was used to evaluate the fitness of the model in terms of prediction results. Categorical multivariate input data (40 variables) was used to construct a classification tree, and the target variable was biosecurity level dichotomized into low versus high. In general, the level of biosecurity was lower in the majority of farms studied, mainly due to the limited implementation of on-farm basic biosecurity measures aimed at controlling the potential introduction and transmission of swine diseases. The CHAID model illustrated the relative importance of significant predictors in explaining the level of biosecurity; maintenance of medical records of treatment and vaccination, use of dedicated clothing to enter the farm, installing fence surrounding the farm perimeter, and periodic monitoring of the herd using written biosecurity plan in place. The misclassification risk estimate of the prediction model was 0.145 with the standard error of 0.025, indicating that 85.5% of the cases could be classified correctly by using the decision rule based on the current tree. Although CHAID approach could provide detailed information and insight about interactions among factors associated with biosecurity level, further evaluation of potential bias intervened in the course of data collection should be included in future studies. In addition, there is still need to validate findings through the external dataset with larger sample size to improve the external validity of the current model.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.11
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• pp.775-784
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• 2017

The purpose of this study was to analyse the basic data of the engine tuning inspection by confirming the working possibility of effective engine tuning and identifying the characteristics of tuned engine that are no problem with the safety operation and environment in a driving gasoline car. The effects of tuned engine on the characteristics of air/fuel ratio and performance at a wide range of engine speeds were experimentally investigated by the actual driving car with a four-cycle, four-cylinder DOHC, turbo-intercooler, water-cooled gasoline engine operating under four types of non-tuning, and tuning 2-1, 2-2 and 2-3. The tuned parts of engine in a driving gasoline car include the intake manifold, intake pipe, air filter, exhaust manifold, exhaust pipe and silencer. In this experiment, the air-fuel ratio and torque of both non-tuned and tuned engines that one person took on board in the car with a five-speed automatic transmission were measured by the chassis dynamometer(Dynojet 224xLC). It was found that the maximum torque of tuned engine in a driving gasoline car was increased by 103.68% on average, while the maximum output was increased by 119.68% on average in comparison to the non-tuned engine.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.263-273
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• 2019

South Korea's OF cable is reaching its expected design life of 30 years, and as a result, the risk of failure is increasing. Therefore, it is necessary to diagnose the long-term operating OF cables through accurate diagnosis at the right time to prevent the failure. Currently, the KEPCO periodically conducts DGA. However, the gas found in DGA is caused by oil deterioration as well as insulation paper. Therefore, the analysis of the degree of polymerization and furan compounds which is an evaluation of insulation paper considered to be the life of OF cables is required. In addition, the results of the evaluation of deterioration of insulation paper need to be checked for correlation with the results of DGA. In this study, DGA carried out through GC, the degree of polymerization was analyzed using an automatic viscometer, and HPLC was used to detect the furan compounds. In addition, the obtained results were applied to the SVM technique, which was recently introduced to determine abnormalities in OF cable. And the results which were accurate and reliable were obtained.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.10
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• pp.377-382
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• 2018

This study deals with internal state and tissue density analysis methods for red ginseng grade determination. For internal measurement of red ginseng, there have been various studies on nondestructive testing methods since the 1990s, It was difficult to grasp the most important inner hole and inside whites in the grading. So in this study, we developed a closed capturing device for infra-red illumination environment, and developed an internal measurement system that can detect the presence and diameter of inner hole and inside whites. Made devices consisted of infrared lights with a high transmission rate of red ginseng in 920 nanometer wave band, a infra-red camera and a Y axis actuator with a red ginseng automatically controlled focus on the camera. The proposed algorithm performs an auto-focus system on the Y-axis actuator to automatically adjust the sharp focus of the object according to the size and thickness. Then red ginseng is rotated $360^{\circ}$ at $1^{\circ}$ intervals and 360 total images are acquired, and reconstructed as a sinogram through Radon transform and Back-projection algorithm was performed to acquire internal images of red ginseng. As a result of the algorithm, it was possible to acquire internal cross-sectional image regardless of the thickness and shape of red ginseng. In the future, if more than 10,000 different shapes and sizes of red ginseng internal cross-sectional image are acquired and the classification criterion is applied, it can be used as a reliable automated ginseng grade automatic measurement method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1107-1114
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• 2004

System Packet Interface Level 4 Phase 2(SPI-4.2) is an interface for packet and cell transfer between a physical layer(PHY) device and a link layer device, for aggregate bandwidths of OC-192 ATM and Packet Over Sonet/SDH(POS), as well as 10Gbps Ethernet applications. SPI-4.2 core consists of Tx and Rx modules and supports full duplex communication. Tx module of SPI-4.2 core writes 64-bit data word and 14-bit header information from the user interface into asynchronous FIFO and transmits DDR(Double Data Rate) data over PL4 interface. Rx module of SPI-4.2 core operates in vice versa. Tx and Rx modules of SPI-4.2 core are designed to support maximum 256-channel and control the bandwidth allocation by configuring the calendar memory. Automatic DIP4 and DIP-2 parity generation and checking are implemented within the designed core. The designed core uses Xilinx ISE 5.li tool and is described in VHDL Language and is simulated by Model_SIM 5.6a. The designed core operates at 720Mbps data rate per line, which provides an aggregate bandwidth of 11.52Gbps. SPI-4.2 interface core is suited for line cards in gigabit/terabit routers, and optical cross-connect switches, and SONET/SDH-based transmission systems.