• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.26-32
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• 2019

This study was conducted to analyze the stresses by impact loads on front-end loaders attached to tractors using flexible multi-body dynamics. The model was designed and validated by comparing previous experimental data with the simulation data obtained in this study. Nine sets of conditions were designed using three weights (500, 300, and 100 kg) loaded inside a bucket and three heights (1700, 1350, and 1000 mm) of the bucket from ground level. A parametric study was carried out at five locations for two types of parts of a front-end loader. All the safety factors for the five locations under all conditions were calculated and were greater than 1. Thus, the designs of the front-end loaders were structurally safe. Based on this study, front-end loaders attached to tractors can be designed effectively in terms of cost and safety.

• Journal of Positioning, Navigation, and Timing
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• v.6 no.1
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• pp.1-8
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• 2017

In this study, to design a multi-GNSS receiver using single RF front-end, the receiving performances for various frequency plans were evaluated. For the fair evaluation and comparison of different frequency plans, the same signal needs to be received at the same time. For this purpose, two synchronized RF front-ends were configured using USRP X310, and PC-based software was implemented so that the quality of the digital IF signal received at each front-end could be evaluated. The software consisted of USRP control, signal reception, signal acquisition, signal tracking, and C/N0 estimation function. Using the implemented software and USRP-based hardware, the signal receiving performances for various frequency plans, such as the signal attenuation status, overlapping of different systems, and the use of imaginary or real signal, were evaluated based on the C/N0 value. The results of the receiving performance measurement for the various frequency plans suggested in this study would be useful reference data for the design of a multi-GNSS receiver in the future.

• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.1
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• pp.47-54
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• 2022

All things connected to the Internet have to ensure interoperability between each other. Web of Things (WoT) is an Internet of Things (IoT) Web standard technology that enables the communication between smart devices and web-based applications. In order for WoT to be possible, monitoring of all devices connected to the Internet have to be possible. To this end, various efforts are being made to develop network monitoring applications using the latest Web front-end frameworks, not traditional web-based monitoring. This paper examines and describes the possibilities of applying Web front-end frameworks such as React, Angular and Svelte to the development of network monitoring applications for WoT. This paper also describes the pros and cons of two major frameworks, React and Angular, in developing monitoring applications that support the cross-platforms and cross-browsers in WoT environments and examines the applicability of them by developing simple network monitoring applications using React.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.11-12
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• 2010

This paper reviewed and analyzed converters for SRM drive. SR converter has two parts, front ends and power converter. Since the capacitive front-end is widely used in voltage source converter, this paper focuses on topologies with the front-end. A novel classification of power converters for SR drives based on the commutation type is also introduced and analyzed.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.380-382
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• 2008

• IT SoC Magazine
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• s.19
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• pp.37-42
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• 2007

이 글은 당사에서 개발 진행한 TDMB,ISDB-T등의 Moblie TV Receiver단의 Analog Front-End SIP들의 Test H/W, S/W제작 경험을 바탕으로 보다 효율적이고 성공적인 SIP 개발이 될 수 있도록 도움을 주고자 기술 하였다.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.143-151
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• 2008

In this paper, we have implemented a ubiquitous healthcare system that can measure and check human's health in anytime and anywhere. The implemented prototype are composed of both front-end and back-end. The front-end have several groups: environment sensor group such as temperature, humidity, photo, voice sensor, health sensor group such as blood pressure, heart beat, electrocardiogram, spo2 sensor, gateway for wired/wireless communication, and RFID reader to identify personal. The back-end has a serial forwarder to propagate measurment results, monitor program, and medical information server The implemented sensor node constructs a sensor network using the Zigbee protocol and is ported the tinyOS. The data gathering base node is linux-based terminal that can transfer a sensed medial data through wireless LAN. And, the medical information server stores the processed medical data and can promptly notify the urgent status to the connected medical team. Through our experiments, we've confirmed the possibility of ubiquitous healthcare system based on sensor network using the Zigbee.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.921-924
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• 2007

In this paper, we have implemented a ubiquitous healthcare system that can measure and check human's health in anytime and anywhere. The implemented prototype are composed of both front-end and back-end. The front-end have several groups: environment sensor group such as temperature, humidity, photo, voice sensor, health sensor group such as blood pressure, heart beat, electrocardiogram, spo2 sensor, gateway for wired/wireless communication, and RFlD reader to identify personal. The back-end has a serial forwarder to propagate measurment results, monitor program, and medical information server. The implemented sensor node constructs a sensor network using the Zigbee protocol and is ported the TinyOS. The data gathering base node is linux-based terminal that can transfer a sensed medial data through wireless LAN. And, the medical information server stores the processed medical data and can promptly notify the urgent status to the connected medical team. Through our experiments, we've confirmed the possibility of ubiquitous healthcare system based on sensor network using the Zigbee.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.34-39
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• 2016

A low-voltage, low-power analog front-end IC for neural recording implant devices is presented. The proposed IC consists of a low-noise neural amplifier and a programmable active bandpass filter to process neural signals residing in the band of 1 Hz to 5 kHz. The neural amplifier is based on a source-degenerated folded-cascode operational transconductance amplifier (OTA) for good noise performance while the following bandpass filter utilizes a low-power current-mirror based OTA with programmable high-pass cutoff frequencies from 1 Hz to 300 Hz and low-pass cutoff frequencies from 300 Hz to 8 kHz. The total recording analog front-end provides 53.1 dB of voltage gain, $4.68{\mu}Vrms$ of integrated input referred noise within 1 Hz to 10 kHz, and noise efficiency factor of 3.67. The IC is designed using $18-{\mu}m$ CMOS process and consumes a total of $3.2{\mu}W$ at 1-V supply voltage. The layout area of the IC is $0.19 mm^2$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.4
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• pp.362-370
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• 2010

In this paper, a compact RF Front-end module for Wireless Fidelity(Wi-Fi) and Worldwide Interoperability for Microwave Access(WiMAX) applications is realized by low temperature co-fired ceramic(LTCC) technology. The RF Front-end module is composed of three LTCC band-pass filters, a Film Bulk Acoustic Resonator(FBAR) filter, fully embedded matching circuits, an SPDT switch for mode selection, an SPDT switch for Tx/Rx selection, and an SP4T switch for band selection. The parasitic elements of 0.2~0.3 pF are generated by the structure of stacking in the top pad pattern for DC block capacitor of SPDT switch for mode selection. These kinds of parasitic elements break the matching characteristic, and thus, the overall electrical performance of the module is degraded. In order to compensate it, we insert a parallel lumped-element inductor on capacitor pad pattern for DC block, so that we obtain the optimized performance of the RF Front-end module. The fabricated RF front-end module has 12 layers including three inner grounds and it occupies less than $6.0mm{\times}6.0mm{\times}0.728mm$.