• Journal of Biosystems Engineering
• /
• v.13 no.2
• /
• pp.28-37
• /
• 1988

This study was conducted to construct the soil bin system and associated microcomputer-based data acquisition system which is to be used for the effective evaluation of wheel performance. The soil bin system consists of four main parts; soil bin, carriage drive system, test carriage and soil processing carriage. The test carriage was constructed to measure the five performance parameters of testing wheels; pulling forte, motion resistance, sinkage and rotational speed of test wheel, and speed of test carriage. The test wheel is powered by a hydraulic system up to 8 ps. Soil processing carriage was designed to provide uniform test soil condition across the toil bin, and reproduction of soil conditions found satisfiable. The data acquisition system consists of APPLE II PLUS microcomputer, strain amplifier, I/O interface, A/D converter, digital counter and various transducers. It takes about 0.86 seconds to measure a set of performance parameters and store on the floppy disk simultaneously. Series of experiment showed that this system can be used effectively for evaluating the wheel performance associated with soil.

• Journal of Ocean Engineering and Technology
• /
• v.24 no.3
• /
• pp.64-71
• /
• 2010

This paper summarizes the development of an ART control system panel with a touch screen and sensors to measure the roll and roll rate of ships. The control system hardware consists of two micro-processors, analog and digital I/O circuits, various relay circuits, etc. Sensor fusion and moving cross algorithms are implemented to accurately estimate the roll angle and roll period. In addition, the control system adopts a fault detection algorithm to inform users of ART system faults. A touch screen in the control panel can display the ART system states and faults. The performance of the developed system was verified on real sea trials.

• ETRI Journal
• /
• v.33 no.6
• /
• pp.897-903
• /
• 2011

A hybrid ${\Delta}{\Sigma}$ modulator for audio applications is presented in this paper. The pulse generator for digital-to-analog converter alleviates the requirement of the external clock jitter and calibrates the coefficient variation due to a process shift and temperature changes. The input resistor network in the first integrator offers a gain control function in a dB-linear fashion. Also, careful chopper stabilization implementation using return-to-zero scheme in the first continuous-time integrator minimizes both the influence of flicker noise and inflow noise due to chopping. The chip is implemented in a 0.13 ${\mu}m$ CMOS technology (I/O devices) and occupies an active area of 0.37 $mm^2$. The ${\Delta}{\Sigma}$ modulator achieves a dynamic range (A-weighted) of 97.8 dB and a peak signal-to-noise-plus-distortion ratio of 90.0 dB over an audio bandwidth of 20 kHz with a 4.4 mW power consumption from 3.3 V. Also, the gain of the modulator is controlled from -9.5 dB to 8.5 dB, and the performance of the modulator is maintained up to 5 nsRMS external clock jitter.

• International Journal of Computer Science & Network Security
• /
• v.22 no.12
• /
• pp.13-18
• /
• 2022

In the post-information era, most of technologies have a visual part, or at least some functions related to visualization. It is also one of the popular means of presenting materials in education area. However, despite its popularity, the impact of visualization on the effectiveness of learning still remains controversial. Even more controversial is its usefulness in developing creativity, which is one of the most important skills for today's employee. The authors considered the use of visualization as a tool for the development of children's creativity on the example of learning video games, in particular, ClassCraft to distinguish features that, from the point of view of psychology, may lead to developing creativity even being not useful for educational purposes. It is concluded that video games useful for learning may have features, that are inappropriate in formal educational context, but important to develop creative thinking.

• Journal of Veterinary Clinics
• /
• v.29 no.1
• /
• pp.18-22
• /
• 2012

This study was performed to evaluate the sensitivity of conventional film-screen radiography (CFSR) and direct digital radiography (DDR) for detection of various amounts of free peritoneal fluid. Ten adult male healthy beagles were used in this study. Radiographic examinations were performed in the right lateral and ventrodorsal positions. Fluid was injected in increments of 2.0 ml/kg of body weight up to 20.0 ml/kg of body weight. The images of CFSR and DDR were evaluated by two veterinary radiologists for evidence of abdominal fluid without knowledge of injected fluid volume. Data were evaluated by using the receiver operation curve (ROC) analysis and the area under the curve (AUC). There was no significant difference in detection of peritoneal fluid between DDR and CFSR in the ROC analysis. The accuracy of CFSR (0.805) was relatively higher than that of DDR (0.733), based on the ROC analysis and AUC. AUC of CFSR was higher in most injection doses. These results suggest that CFSR is more accurate than DDR for the detecting peritoneal fluid. Therefore, for situation in which digital radiographs are equivocal or small amount of fluid is suspected, other imaging modalities, such as ultrasonography would be helpful for determining the presence of fluids.

• Journal of the Korea Convergence Society
• /
• v.8 no.9
• /
• pp.249-254
• /
• 2017

The purpose of this study is to provide a way to develop the information quality of mobile real estate service and improve the false property through search filter service. I compared the cases of typical mobile real estate apps that are currently in use and analyzed the usage and service status by adopting 13 search filters that are the first priority when searching for real estate information. As a result, it has been shown that the provision of high quality search filter service is required to improve the information quality in order to provide users with quick and reliable information organically at any time and anywhere according to the definition of mobile real estate service. As a result, it is more prejudiced than the countermeasures against false fraudulent products, and it is satisfied with the needs of the users and provides the improved search filter service, so that it can be trusted with the definition of mobile real estate brokerage service, Providing quality services can be said to prevent the victims of fraudulent products.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.11
• /
• pp.1109-1117
• /
• 2017

In this work, a new control module and communication system associated with DSP are proposed to overcome the limitations of the contemporary prevailing PLC-based industrial equipment controller, and the performance of the proposed system was experimentally verified. In the light of this issue, a communication conversion scheme from RS-485 to Modbus, the dominant communication protocol used by PLC, was developed and shown to yield enhanced compatibility between devices. The proposed system allows for ~50％ cost reduction as well as downsizing of the industrial controllers. Furthermore, the design includes 24 V general digital I/O pins, which facilitate partial expansion of inputs and outputs. With Modbus communication implemented in DSP with the RS-485 interface, multi-to-multi communication may also be achieved.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.4
• /
• pp.2784-2790
• /
• 2015

The column-oriented database storage is a very advanced model for large-volume data transactions because of its superior I/O performance. Traditional data storages exploit row-oriented storage where the attributes of a record are placed contiguously in hard disk for fast write operations. However, for search-mostly data warehouse systems, column-oriented storage has become a more proper model because of its superior read performance. Recently, solid state drive using flash memory is largely recognized as the preferred storage media for high-speed data analysis systems. In this research, we propose a new transaction recovery scheme for a column-oriented database environment which is based on a flash media file system. We improved traditional shadow paging schemes by reusing old data pages which are supposed to be invalidated in the course of writing a new data page in the flash file system environment. In order to reuse these data pages, we exploit reused shadow list structure in our column-oriented shadow recovery(CoSR) scheme. CoSR scheme minimizes the additional storage overhead for keeping shadow pages and minimizes the I/O performance degradation caused by column data compression of traditional recovery schemes. Based on the results of the performance evaluation, we conclude that CoSR outperforms the traditional schemes by 17%.

• Journal of IKEEE
• /
• v.21 no.3
• /
• pp.268-271
• /
• 2017

In this paper, we propose the development of high resolution $360^{\circ}$ omnidirectional IP camera with 12 million pixels. The proposed 12-megapixel high-resolution $360^{\circ}$ omnidirectional IP camera consists of a lens unit with $360^{\circ}$ omnidirectional viewing angle and a 12-megapixel high-resolution IP camera unit. The lens section of $360^{\circ}$ omnidirectional viewing angle adopts the isochronous lens design method and the catadioptric facet production method to obtain the image without peripheral distortion which is inevitably generated in the fisheye lens. The 12 megapixel high-resolution IP camera unit consists of a CMOS sensor & ISP unit, a DSP unit, and an I / O unit, and converts the image input to the camera into a digital image to perform image distortion correction, image correction and image compression And then transmits it to the NVR (Network Video Recorder). In order to evaluate the performance of the proposed 12-megapixel high-resolution $360^{\circ}$ omnidirectional IP camera, 12.3 million pixel image efficiency, $360^{\circ}$ omnidirectional lens angle of view, and electromagnetic certification standard were measured.

• Korean Journal of Heritage: History & Science
• /
• v.53 no.2
• /
• pp.36-63
• /
• 2020

Percival Lowell took photographs of 80s during his stay in Korea in the winter of 1883 and 1884. The photographs are the first in the history of Korea and contain various and precious information about Korea of the day. As such, they could be used for purposes of studying late 19th century Chosōn society. The 61 photographs that are archived in Boston Museum of Fine Art were catalogued by National Research Institute of Cultural Heritage and have been posted online with incorrect explanations by Boston Museum of Fine Art. The explanations have been composed and revised at least four times on the basis of Lowell's writings and archivists' understandings of Korea. However these explanations contain many errors regarding the content of the photographs, yet have been cited by researchers and books concerning the history of Korea. I examined the explanations, analyzed Lowell's writings and diplomatic documents, and confirmed the locations where the photographs were taken. Accordingly, I suggest improved explanations of the photographs to prevent misuse of the Boston Museum of Fine Art's online archive. Lowell's photographs of Chosōn have very high historical value and could be used in various cultural fields because of their various contents and high definition. However, they belong to America and are not cared for sufficiently. Therefore, I suggest that high definition digital scans and prints of the photographs be generated for the sake of overseas Korean cultural heritage collection.