Coherent and Semi-Coherent Correlation Detection of DSSS-FSK Signals for Low-Power/Low-Cost Wireless Communication

박형철,Park Hyung Chul The Institute of Electronics and Information Engin 2005 電子工學會論文誌-TC (Telecommunications) Vol.42 No.4

본 논문에서는 송신기와 수신기의 구현에 있어서 많은 장점을 제공하는 직접 확산-주파수(DSSS-FSK) 변조를 제안한다. 주파수 변조를 사용하여, 직접 확산 통신에서도 주파수합성기(PLL)를 이용한 송신기의 구현이 가능하므로 저전력, 저가격이 가능하다. 또한, 반송과 인접 대역에 정보를 전송하지 않아서 직접변환방식 수신기(DCR)의 구현을 용이하게 한다 한편, DSSS-FSK 신호를 위한 최적 동기 검파와 반동기 상관 검파 구조를 제안하고 그 성능을 분석한다. 매우 큰 반송파 주파수오프셋에서도 우수한 비트오율성능을 가지기 위해서, 분할 반동기 상관 검파 구조를 제안하고 성능을 분석한다. For the low power and low cost transceivers, direct sequence spread spec01m frequency-shift keying (DSSS-FSK) is proposed. A transmitter of the DSSS-FSK signal can be implemented by a simple direct modulation using the phase locked loop. Since the DSSS-FSK signal has negligible power around the carrier frequency, low cost direct conversion receiver can be used. Optimum coherent and semi-coherent correlation detection methods for the DSSS-FSK signal are proposed and analyzed. Segmented semi-coherent correlation detection method is proposed to improve the bit error rate performance in the large carrier frequency offset.

IoT 기술과 디스플레이 응용

박형철,Park, Hyeong-Cheol 한국정보디스플레이학회 2017 인포메이션 디스플레이 Vol.18 No.3

저출생체중아의 출생과 산모의 제요인과의 연관성

박형철,박종,이윤지,문강,Park, Hyung-Cheol,Park, Jong,Lee, Youn-Ji,Moon, Gang 대한예방의학회 1991 Journal of Preventive Medicine and Public Health Vol.24 No.3

This study was performed to identify the maternal risk factors for the low birth weight. During the period from February to June in 1991, the medical record review and questionnaire interview were conducted upon the 465 pregnant women who were admitted to and delivered a baby in 3 general hospitals and an obstetric hospital in Kwangju area. The health and other related information from women who bore the low birth weight infant was compared with those from women who bore the normal birth weight infant. The results obtained were as follows : 1. Maternal age, low body weight at term, illegitimate birth, and maintaining work activity during pregnancy were positively associated with low birth weight. 2. The positive association was revealed between low birth weight and the previous abortion, short gestational weeks, anemia, low maternal weight gain during pregnancy, the obstetric present illness and hypertension. 3. Some maternal working conditions were associated with low birth weight although statistically not significant. 4. In multivariate logistic regression analysis, gestational weeks and maternal weight gain during pregnancy were related with low birth weight.

층고절감 및 내화성능 향상을 위한 iTECH 합성보

박형철,이성호,Park, H.C.,Lee, S.H. 한국전산구조공학회 2011 전산구조공학 Vol.24 No.2

Multiple Orthogonal Subcarrier Modulation based High-Speed UHF RFID System for Multiple-/Dense-Interrogator Environments

박형철,Park, Hyung Chul The Institute of Electronics and Information Engin 2016 전자공학회논문지 Vol.53 No.9

본 논문에서는 다중 직교 부반송파 변조 기반의 새로운 UHF RFID 통신 시스템을 제안한다. 태그 송신-리더 수신 통신에서는 4 부반송파를 이용하여 1.6 Mbps까지 전송속도를 향상시킬 수 있다. 회로의 복잡도 증가를 억제하면서도 전송 속도를 향상시키기 위해서, 태그는 부반송파로서 구형파를 사용하고 각 부반송파는 각각의 부하변조기를 이용한다. 다중 직교 부반송파 기반의 변조 방식을 사용하였기 때문에 제안한 통신 방식은 기존의 UHF 대역 RFID 규격을 만족한다. 리더는 OFDM 복조기를 사용한다. 태그가 리더의 CW 반송파를 역산란하므로 리더 복조기에는 반송파 주파수 오프셋 보정회로는 필요하지 않다. 실험에서는 개발 시스템은 10.8 dB의 잡음 밀도당 비트에너지 비에서 10-5의 비트오율 성능을 가짐을 보인다. This paper presents a novel multiple orthogonal subcarrier modulation based UHF band RFID communication system. In tag-to-reader communication, the demonstration system can deliver 1.6 Mbps through four subcarriers. To improve data rate while suppressing increase in circuit complexity, tag employs square-waves as the subcarriers and uses individual load modulators for each subcarrier. By using multiple orthogonal subcarrier based modulation, proposed communication system can be operated under existing UHF band RFID regulation. In reader, an OFDM demodulator is used. Since the tag backscatters the reader's CW carrier, carrier frequency offset compensation is not necessary in reader demodulator. Experimental results show that the demonstration system achieves a bit error rate of 10-5 at an Eb/N0 of 10.8 dB.

Novel MAP kinase substrates identified by solid-phase phosphorylation screening in Arabidopsis thaliana

박형철,Xuan Canh Nguyen,Sunghwa Bahk,Byung Ouk Park,김호수,Min-Chul Kim,Hans J. Bohnert,정우식 한국식물생명공학회 2016 Plant biotechnology reports Vol.10 No.6

Phosphorylation of substrate proteins by mitogen-activated protein kinases (MPKs) determines the specific cellular responses elicited by a particular extracellular stimulus. However, downstream targets of plant MPKs remain poorly characterized. In this study, 29 putative substrates of AtMPK3, AtMPK4 and AtMPK6 were identified by solid-phase phosphorylation screening of a k phage expression library constructed from combined mRNAs from salt-treated, pathogen-treated and mechanically wounded Arabidopsis seedlings. To test the efficiency of this screening, we performed in vitro kinase assay with 10 recombinant fusion proteins. All proteins were phosphorylated by AtMPK3, AtMPK4 and AtMPK6, indicating the efficiency of this screening procedure. To confirm phosphorylation of isolated substrates by plant MPKs, we performed in-gel kinase assays. All test substrates were strongly phosphorylated by wounding or H2O2-activated AtMPK3 and AtMPK6. Three substrates, encoded by genes At2g41430, At2g41900, and At3g16770, were strongly phosphorylated, suggesting a function as AtMPK substrates. The type of screening provides a powerful way for identifying potential substrates of MAP kinases responsive to biotic and abiotic stresses.

고장 주입 시뮬레이션 기반 자율주행 자동차의 안정성 분석 및 고장안전 사양 도출

박형철(Hyungchul Park),신민우(Minu Shin),권철현(Cheolhyeon Kwon) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.6

본연구는 고장 주입 시뮬레이션을 통해 자율주행 차량의 고장에 대한 잠재적 위험성을 분석하고, 이를 통해 고장 발생시 자율주행차량이 대응할 수 있는 안전 메커니즘을 도출하고자 하였다. 포괄적이면서도 철저한 고장 주입 시뮬레이션 수행을 위해, i)MATLAB Simulink 기반의 14 자유도 차량 동역학 모델 및 오픈소스 기반의 자율주행 알고리즘을 구현하고; ii)미국 도로교통안전국 문서를 기반으로 차량 핵심 부품 별 고장 유형 및 도로 주행 시나리오를 세분화하였다. 또한, 차량 거동의 위험성 평가를 위해 Responsibility-Sensitive Safety (RSS) 개념을 적용하여 주입한 고장과 주행 시나리오 조합에 대한 정량적인 분석을 수행하였다. 분석 결과를 바탕으로 기존 자율주행 알고리즘에 추가적인 고장 대응안전사양을 추가적으로 적용하였고, 시뮬레이션을 통해 그 유효성을 확인하였다. This paper employs the software-in-the-loop fault injection test (FIT) methodology to develop the fail-safe mechanism of an autonomous driving car against various fault scenarios. To perform the comprehensive and exhaustive FIT, we implement: i) MATLAB Simulink-based 14DOF vehicle dynamics model and open-source based autonomous driving algorithms; and ii) diverse fault types with different driving scenarios according to the National Highway Traffic Safety Administration documents. Besides, the responsibility-sensitive safety concept is adopted to quantify the threat of individual faulty scenarios. Based on the FIT results, we further implement the corresponding fail-safe requirements into the autonomous driving algorithm, whose effectiveness is validated through the simulation.

위장관 ; 위장관기질종양과 구별되는 위 신경초종의 초음파 내시경 특징

박형철 ( Hyung Chul Park ),손동준 ( Dong Jun Son ),오형훈 ( Hyung Hoon Oh ),옥찬영 ( Chan Young Oak ),김미영 ( Mi Young Kim ),정조윤 ( Cho Yun Chung ),명대성 ( Dae Seong Myung,),김종선 ( Jong Sun Kim ),조성범 ( Sung Bum Cho ),이 대한소화기학회 2015 대한소화기학회지 Vol.65 No.1

Background/Aims: Gastric schwannoma (GS), a rare neurogenic mesenchymal tumor, is usually benign, slow-growing, and asymptomatic. However, GS is often misdiagnosed as gastrointestinal stromal tumors (GIST) on endoscopic and radiological examinations. The purpose of this study was to evaluate EUS characteristics of GS distinguished from GIST. Methods: A total of 119 gastric subepithelial lesions, including 31 GSs and 88 GISTs, who were histologically identified and underwent EUS, were enrolled in this study. We evaluated the EUS characteristics, including location, size, gross morphology, mucosal lesion, layer of origin, border, echogenic pattern, marginal halo, and presence of an internal echoic lesion by retrospective review of the medical records. Results: GS patients comprised nine males and 22 females, indicating female predominance. In the gross morphology according to Yamada`s classification, type I was predominant in GS and type III was predominant in GIST. In location, GSs were predominantly located in the gastric body and GISTs were predominantly located in the cardia or fundus. The frequency of 4th layer origin and isoechogenicity as compared to the echogenicity of proper muscle layer was significantly more common in GS than GIST. Although not statistically significant, marginal halo was more frequent in GS than GIST. The presence of an internal echoic lesion was significantly more common in GIST than GS. Conclusions: The EUS characteristics, including tumor location, gross morphology, layer of origin, echogenicity in comparison with the normal muscle layer, and presence of an internal echoic lesion may be useful in distinguishing between GS and GIST.

Wi-Fi Direct 를 이용한 차량 및 보행자 안전 응용 설계 및 구현

박형철(Hyeongcheol Park),문은배(Eunbae Moon),이성원(Sungwon Lee),김동균(Dongkyun Kim) 한국통신학회 2017 한국통신학회 학술대회논문집 Vol.2017 No.1

성서와 그리스 비극에 나타나는 인간 실존 관련 단어들에 대한 비교 연구

박형철(Hyung Chul Park) 대한성서공회 2016 성경원문연구 Vol.- No.38

This paper examines four Greek words (hubris-hamartia-thanatos-phobos) for human existence in the Bible and the Greek tragedy. While the Bible says that a man is subject to death because of sin, a tragic hero in Greek tragedy dies because of his hamartia. Both perspectives commonly show that human beings live in fear of predestined death. This study aims at re-explaining human existence with four words that a human being is subjected to thanatos because of hubris/hamartia and he lives his life in phobos. After comparing, analyzing and synthesizing four Greek words in the Bible and the Greek tragedy, I have tried to reconstruct and reinterpret them. In due course, human existence will be explained within the intertextuality between the Bible and the Greek tragedy. And this could provide a new approach in translating and interpreting the Bible. Besides these four Greek words, this paper also looks for other words in the Greek tragedy that are related to human life and existence in the Bible. By comparing and applying their meaning, this study will enlighten and suggest new approaches to translating and interpreting how humans are portrayed in the Bible. This study could also suggest new possibilities of rethinking the notion of salvation of human existence not only in the Bible but also in the Greek tragedy. I hope that this study might contribute to broadening the horizon of the biblical text in its exploration of constructive dialogue between the Bible and the Greek tragedy.