The Design and Implementation of a DVB-RCS Modulator Using Single FPGA

Jeong, Hoon,Lee, Seung-Joon,Cho, Yong-Hoon 통신위성우주산업연구회 2001 Joint Conference on Satellite Communications Vol.2001 No.-

This paper presents the design and implementation of a DVB-RCS return channel modulator using FPGA. The DVB-RGS standard was finalized by DVB in 2000. It provides an efficient way for accessing Internet via satellite. In the DVB-RCS standard, the Multi-Frequency Time Division Multiple Access (MF-TDMA) is used for return channel.. To support the DVB-RCS standard, the return channel modulator has to operate differently timeslot by timeslot, since different timeslots may have different frequencies, transmit symbol rates, or channel codes. For implementation of a DVB-RCS modulator, just one XILINX VIRTEX-E 1600 FPGA is used with some peripherals. This FPGA is designed to have three functional modules, the Parameter store and management module, the Burst generation module, and the Modulation module. The results of this paper show the possibility of the one-chip solution for the DVB-RCS modulator.

Using Pulse-Front Tilt to Measure Laser Pulses Less Than 100 Picoseconds in Duration

Jeong, Hoon Optical Society of Korea 2015 한국광학회지 Vol.26 No.6

We demonstrate a frequency-resolved optical grating (FROG) device for measuring the intensity and phase versus time of several-tens-of-picoseconds laser pulses, using a thick nonlinear optical crystal. The huge pulse-front tilt generated by a holographic grating increases the temporal range of the device, which can make a single-shot measurement of laser pulses less than 100 ps in duration. To verify the measurement technique, we generate double pulses using a Michelson interferometer. The measured duration of a single pulse is about 300 fs and the measured maximum delay of two pulses is 60 ps, which implies that the proposed FROG device can measure laser pulses with maximum pulse width of about 120 ps.

Reducing hops without extra power: Impact of deployment height on low-power multihop wireless network

Jeong, Hoon,Lee, Changwon,Ryu, Jaehong,Choi, Byung-Chul,Ko, JeongGil,Paek, Jeongyeup Taylor & Francis 2017 INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWOR Vol.13 No.9

Output power improvement in an Yb-doped fiber laser with an additional unpumped Yb-doped fiber

Jeong, Hoon,Park, Hyoyeong,Kim, Seungtaek,Kim, Jongseok,Byun, Chulsoo,Kim, Cheolho Springer-Verlag 2012 Optical review Vol.19 No.2

이주(移住)의 서사(敍事)와 고려인 공동체의 미래 ― 광주 고려인마을 거주 고려인의 구술생애담을 대상으로 ―

한정훈 ( Han¸ Jeong-hoon ) 전남대학교 호남학연구원 2020 호남학 Vol.0 No.68

본 논문은 광주 고려인마을에 거주하는 이주민 고려인의 구술생애담을 대상으로 개인과 공동체의 문제를 다양한 층위에서 살펴보는 것을 목적으로 한다. 고려인은 강제 이주 후에 소비에트 체제에 철저히 동화하기 시작했다. 그리고 고려인은 ‘소비에트 인민’으로서 집단의 정체성을 구성하면서 구소련 사회에 나름의 입지를 구축했다. 구소련이 해체된 이후 중앙아시아 국가들은 정치·경제·사회적 측면에서 불안정이 계속되었고, 고려인은 기존의 정체성과 사회적 지위를 유지할 수 없었다. 경제 발전을 이룩한 한국은 고려인이 이주하기에 매력적인 장소였다. 하지만 한국은 낭만적으로 상상했던 ‘조상의 나라’가 아니었다. 신자유주의 체제와 각종 효율성이 일상을 지배하는 장소였다. 고려인은 외모가 비슷할 뿐, 현대의 한국인과 동일할 수 없는 위치에 있음을 깨닫는다. 끊임없이 접촉해 오는 타자적 시선은 한국 사회에서 나름의 사회적 정체성 정립을 고려인에게 요구했다. 고려인의 한국 이주가 시간이 지나면서 세대를 달리하며 이어지고 있다. 본 연구는 고려인의 한국 이주가 시간의 흐름 속에서 어떤 모습으로 진행되었고, 그 과정에서 고려인 개인과 그들의 공동체가 어떤 대응을 하였는가를 살펴보고자 한다. 나아가 고려인의 이주 세대가 바뀌어감에 따라 어떤 문제들이 새롭게 적층해 가고 있는 살펴보고자 한다. The purpose of this study is to examine the problems of individuals and communities from various levels focusing on oral life narratives of migrants, Goryeo people living in the Goryeo people village in Gwangju city. Goryeo people began to assimilate thoroughly into the Soviet system after the forced migration. And Goryeo people, as 'Soviet People', formed their own position in the former Soviet Union, establishing an identity of the group. After the dissolution of the former Soviet Union, Central Asian countries continued to be unstable in terms of politics, economy and society, and Goryeo people were unable to maintain their existing identity and social status. Korea, which achieved economic development, was an attractive place for Goryeo people to migrate. But Korea wasn't the ‘country of ancestors’ that was romantically imagined. The country is where the neoliberal system and various efficiencies were the dominance of everyday life. Goryeo people realize that their appearances are similar, and that they cannot be identical to modern Koreans. The constant contact with people with third-party eyes demanded Goryeo people to establish their own social identity in Korean society. Goryeo people's migration to Korea continues over generations as time goes. This study attempts to examine how Goryeo people's migration to Korea has progressed, and in the process, how Goryeo people and their communities responded. Furthermore, this study attempts to investigate what problems are newly stacked up as the migration generation of Goryeo people changes.

A Study on the Utilization of the National Occupational Competency Standards for the Development of Security Field

Jeonghoon Ha(Jeonghoon Ha) J-INSTITUTE 2022 International Journal of Terrorism & National Secu Vol.7 No.2

Purpose: In Korea's industrial sites, the state standardizes the skills required to perform duties and supports to foster the field-oriented talents, yet the use of the National Occupational Competency Standards in the security industry is very inadequate. Method: In this study, the current status of the security industry and the operation of the National Occupa-tional Competency Standards are reviewed, and the National Occupational Competency Standards for the devel-opment of the security industry are conducted based on the interviews with the experts applying to the security industry using the National Occupational Competency Standards towards the efficient use of the Standards. Results: In the security industry, the National Occupational Competency Standards are not functioning properly given the dual contents provided by the existing Security Services Industry Act and the new National Occupational Competency Standards. Accordingly, it is required to change the legislative system which can more actively utilize the Security Services Industry Act and National Occupational Competency Standards and further improve the National Occupational Competency Standards. Conclusion: For the development of the security industry, this study presents the following conclusions. First, in the security industry and the NCS-based education system, the curriculum of the Security Services Industry Act and the education system of the NCS must be unified to reestablish the curriculum. Second, the classification of the duties of the Security Services Industry Act and the level of the NCS according to the occupational rating must be reestablished in a systematic and progressive direction by comprehensively examining the industrial reality and foreign cases. Third, it must be redeveloped as a comprehensive and efficient model by collecting the opin-ions of experts in each field for the inspection of the security industry and the NCS-based system.

The Effect of Mobile MMORPG Characteristics on Flow Experience and Performance

Jeonghoon LEE 한국유통과학회 2019 유통과학연구 Vol.17 No.8

Purpose - This study examines the changes in the mobile MMORPG market in recent years and the factors affecting the performance of mobile games through flow experience according to the characteristics of game content. Research design, data, and methodology - This study focuses on the fact that the cause of game use behavior changes is the flow experience which influences the duration of mobile game continuation. The flow experience and the influencing factors are divided into the relationship between first, second-leading factors, and lagged factors. Results - The user`s sense of challenge, skillfulness, concentration, and reality influenced the flow experience as a leading factor influencing the performance of MMORPG games. On the other hand, fun and preference were found to be the outcomes of the flow experience. This is because the game content is experienced not through passive enjoyment but by intentionally enjoying the game content. The flow experience has a positive effect on the intention of continuous use as in the previous study. Conclusions - This study found that the flow experience of game users is necessary for continuous use by organizing relationships of flow experience in mobile MMORPG users' gaming behavior.

A Practical Power System Stabilizer Tuning Method and its Verification in Field Test

Jeonghoon Shin,Suchul Nam,Jaegul Lee,Seungmook Baek,Youngdo Choy,Taekyun Kim 대한전기학회 2010 Journal of Electrical Engineering & Technology Vol.5 No.3

This paper deals with parameter tuning of the Power System Stabilizer (PSS) for 612 MVA thermal power plants in the KEPCO system and its validation in a field test. In this paper, the selection of parameters, such as lead-lag time constants for phase compensation and system gain, is optimized using linear and eigenvalue analyses. This is then verified through the time-domain transient stability analysis. In the next step, the performance of PSS is finally verified by the generator's on-line field test. After the field test, measured and simulated data are also compared to prove the effectiveness of the models used in the simulations.

Multi-Paths Multicast Overlay Tree in Hybrid Mobile Ad-Hoc Network (HYMANET)

Jeonghoon Park,Iksoo Kim 보안공학연구지원센터 2014 International Journal of Smart Home Vol.8 No.2

Application of Multi-step Undervoltage Load Shedding Schemes to the KEPCO System

Jeonghoon Shin,Suchul Nam,Jaegul Lee,Youngdo Choy,Taekyun Kim,Hwachang Song 대한전기학회 2009 Journal of Electrical Engineering & Technology Vol.4 No.4

This paper deals with improvements to the special protection schemes (SPS) which have been applied to the low probability and high impact contingencies in the Korea Electric Power Corporation (KEPCO) system since 2004. Among them, the SPS for voltage instability in the Seoul metropolitan area is considered in this paper, and is a form of event-based undervoltage load shedding with a single-step scheme. Simulation results based upon a recent event that occurred on 765㎸ lines show that the current setting values of the SPS have to be revised and enhanced. In addition, by applying response-based multi-step undervoltage load shedding (UVLS) schemes to severe contingencies in the system, more effective results than those of the existing single-step SPS can be obtained. Centralized and distributed UVLS schemes are considered in the simulation. ULTC-based load recovery models and over excitation limiters (OXL) for the KEPCO system are also included in the long-term voltage instability studies.