5G 광중계기 구동을 위한 디지털 송수신 유닛 설계

민경옥(Kyoung-Ok Min),이승호(Seung-Ho Lee) 한국전기전자학회 2021 전기전자학회논문지 Vol.25 No.1

본 논문에서는 5세대 이동통신 네트워크 서비스의 커버리지를 확장하고, 빌딩내에서의 안정적인 무선 네트워크 연결해 주는 5G 광중계기의 인빌딩용 디지털 송수신 유닛 설계를 제안한다. 제안된 5G 광중계기 구동을 위한 디지털 송수신 유닛은 신호처리부, RF 송수신부, 광입출력부, 클록발생부 등의 4개 블록으로 구성된다. 신호처리부는 CPRI 인터페이스의 기본 동작과 4채널 안테나 신호의 조합 및 외부에서의 제어 명령에 대한 응답 등 중요한 역할을 수행한다. 또, JESD204B 인터페이스로 고품질의 IQ 데이터를 송수신 한다. 파워앰프를 보호하기 위해 CFR, DPD 블록이 동작한다. RF 송수신부는 안테나로부터 수신된 RF 신호를 AD 변환하여 JESD204B 인터페이스로 신호처리부에 전달되고, 신호처리부에서 JESD204B 인터페이스로 전달된 디지털 신호를 DA 변환하여 안테나로 RF 신호를 송신한다. 광입출력부는 전기신호를 광신호로 변환하여 송신하고, 광신호를 전기신호로 변환하여 수신한다. 클록발생부는 광입출력부의 CPRI 인터페이스에서 공급되는 동기 클록의 지터(Jitter)를 억제하고, 신호처리부와 RF 송수신부에 안정적인 동기 클록을 공급한다. CPRI 연결전에는 로컬 클록을 공급하여 CPRI 연결 준비 상태로 동작한다. 본 논문에서 제안된 5G 광중계기 구동을 위한 디지털 송수신 유닛의 정확성을 평가하기 위해서 Xilinx 사의 MPSoC 계열의 XCZU9CG-2FFVC900I를 사용하였고 설계 툴은 Vivado 2018.3을 사용하였다. 본 논문에서 제안된 5G 광중계기 디지털 송수신 유닛이 ADC로 입력되는 5G RF 신호를 디지털로 변환하여 CPRI를 통해 JIG로 전달하는 Uplink 동작과 JIG로부터 CPRI를 통해 전달받은 Downlink 데이터 신호를 DAC로 출력하는 기능과 성능을 평가하였다. 실험결과는 평탄도, Return Loss, Channel Power, ACLR, EVM, Frequency Error 등이 목표로 한 설정 값 이상의 성능이 나타남을 확인 할 수 있었다. In this paper, we propose a digital transceiver unit design for in-building of 5G optical repeaters that extends the coverage of 5G mobile communication network services and connects to a stable wireless network in a building. The digital transceiver unit for driving the proposed 5G optical repeater is composed of 4 blocks: a signal processing unit, an RF transceiver unit, an optical input/output unit, and a clock generation unit. The signal processing unit plays an important role, such as a combination of a basic operation of the CPRI interface, a 4-channel antenna signal, and response to external control commands. It also transmits and receives high-quality IQ data through the JESD204B interface. CFR and DPD blocks operate to protect the power amplifier. The RF transmitter/receiver converts the RF signal received from the antenna to AD, is transmitted to the signal processing unit through the JESD204B interface, and DA converts the digital signal transmitted from the signal processing unit to the JESD204B interface and transmits the RF signal to the antenna. The optical input/output unit converts an electric signal into an optical signal and transmits it, and converts the optical signal into an electric signal and receives it. The clock generator suppresses jitter of the synchronous clock supplied from the CPRI interface of the optical input/output unit, and supplies a stable synchronous clock to the signal processing unit and the RF transceiver. Before CPRI connection, a local clock is supplied to operate in a CPRI connection ready state. XCZU9CG-2FFVC900I of Xilinx’s MPSoC series was used to evaluate the accuracy of the digital transceiver unit for driving the 5G optical repeater proposed in this paper, and Vivado 2018.3 was used as the design tool. The 5G optical repeater digital transceiver unit proposed in this paper converts the 5G RF signal input to the ADC into digital and transmits it to the JIG through CPRI and outputs the downlink data signal received from the JIG through the CPRI to the DAC. And evaluated the performance. The experimental results showed that flatness, Return Loss, Channel Power, ACLR, EVM, Frequency Error, etc. exceeded the target set value.

극저전류자극이 손상된 토끼 뇌의 별아교세포 증식에 미치는 효과

김지성,민경옥,Kim, Ji-Sung,Min, Kyoung-Ok 대한물리치료과학회 2002 대한물리치료과학회지 Vol.9 No.3

Astrocyte, which shares the greatest part of the brain (about 25%), is a land of glial cell that composes the central nervous system along with microglia, ependymal cell and oligodendroglia. It has 7-9nm of fibers in its cytoplasma, which are composed of glial fibrillary acidic protein (GFAP) and vimentin. As for the functions of the astrocyte, it has, so far, been supposed that the astrocyte will play a cytoskeletal role in maintaining the structure of the cerebrum, play a role as a blood-brain barrier so that it can induce migration of the neuron in its development and substances in the blood cannot go into the nervous tissue, and a role of immunology and phagocytosis. However, it was revealed today that it will be a role in preventing expansion of injury by attaching itself to the connective tissue such as the vessel and the pia mater when the nervous tissue or the arachnoid is injured. Microcurrent stimulation can control current, on the basis of A unit. That is, with such devices using it, it is possible to sense, from the outside, the injured current(wound current) of the lesion and to change it into the normal current, thereby promoting the restoration of the cells. In order to examine the effects of microcurrent stimulation on the injured astrocytes in the rabbits, this study was conducted with 24 New Zealand White Rabbit as its subjects, which were divided into 8 animals of the experiment group and 16 animals of the control group. After the animals in the experiment group were fixed to the stereotaxic apparatus, their hair was removed and their premotor area(association area) perforated by the micro-drill for skull-perforation with the depth of 8mm from the scalp. In one week after the injury, 4 animals in the control group and 8 animals in the experiment group were sacrificed and examined with immunohistochemical method. And in three weeks, the remaining 4 animals in the control group and 8 animals in the experiment group were also sacrificed and examined with the same way. The conclusion has been drawn as follows : In the control group sacrificed in one week after the injury, the astrocytes somewhat increased, compared with the normal animals, and in the group sacrificed in three weeks after the injury, they increased more (p < 0.05). The experiment group A in one week showed a little increase, but there was no significant differences, but the experiment group in three weeks showed more increase, compared with the experiment group in one week (p < 0.05). The experiment group B in one week showed more increase than the control group or the experiment group A, and the experiment group in three weeks showed more increase than the experiment group in one week (p < 0.05). Among the astrocytes, fibrous astrocytes were mostly observed, increasing as they are close to the lesion, and decreasing as they are remote from it. The findings show that microcurrent can cause the astrocytes to proliferate and that it will be more effective to stimulate the cervical part somewhat remote from the lesion rather than to directly stimulate the part of the lesion. Thus, microcurrent stimulation can be one of the methods that can activate the reaction of astrocytes, which is one of the mechanism for treating cerebral injury with hemorrhage. Therefore, this study will be used as basic research data for promoting restoration of functions in the patient with injury in the central nervous system.

초등학생들의 정신건강, 학업적 자기효능감, 학교생활적응이 휴대전화 중독에 미치는 영향

유향숙 ( Hyang Sook Yoo ),민경옥 ( Kyoung Ok Min ) 한국아동교육학회 2015 아동교육 Vol.24 No.1

이 연구에서는 초등학생의 정신건강, 학업적 자기효능감, 학교생활적응이 휴대전화 중독 간의 관계를 살펴보았다. 본 연구는 초등학교에 재학중인 5학년과 6학년 349명을 대상으로 SPSS 18.0 프로그램을 이용하여 자료를 분석하였다. 연구결과에 따르면, 성별에서는 내성 및 의존이, 그리고 학년에서는 생활장애가 차이가 있는 것으로 나타났다. 둘째, 상관계수에서는 휴대전화 중독의 하위영역인 강박과 학교생활적응의 하위영역인 담임적응이, 그리고 교우적응은 내성·의존, 생활장애, 강박에서는 유의한 차이가 없는 것으로 나타났다. 셋째, 중다회귀분석에서는 휴대전화 중독에 가장 많은 영향을 미치는 요인은 자기조절효능감, 우울, 적대감, 그리고 규칙 및 학교행사가 영향을 주는 변수로 나타났다. 따라서 이러한 결과에 대해 본 연구의 시사점 및 향후 연구방향에 대해 논의하였다. The purpose of the study is to examine the effect of mental health, academic self efficacy, school life adjustment on cellular phone addiction of elementary. 349 elementary students in Daegu and Seoul province were participated in the survey thru convenient sampling and t-test, conducted by correlation analysis and multiple regression. The results are as follows: First, First, the gender tolerance and dependence, and the grades showed that the difference between the living impaired. Second, the correlation coefficient of the child``s adaptation of compulsion and school adjustment of cell phone addiction, tolerance and friendship adaptation. Dependence, life disability, whereas appeared to be no significant difference in the obsessive, the other variables were found to be significantly correlated. Third, the multiple regression analysis, factors that most influence on cellular phone addiction was found to be self-regulating efficacy, depression, hostility, and the rules and variables that affect school activities. Therefore, we discuss the implications of this study and future research directions for these results.

뇌허혈 유발 후 전침자극이 전뇌세포사 중 Bax와 Caspase-3 발현 변화에 미치는 영향 연구

최정현 ( Jung Hyun Choi ),민경옥 ( Kyoung Ok Min ),김순희 ( Soon Hee Kim ),김동일 ( Dong Il Kim ),이상빈 ( Sang Bin Lee ),안호정 ( Ho Jung An ),김지성 ( Ji Sung Kim ),최완석 ( Wan Suk Choi ),김보경 ( Bo Kyoung Kim ),송치원 ( Chi W 대한한방신경정신과학회 2010 동의신경정신과학회지 Vol.21 No.1

Objectives: The study aims to look into how the application of EA(Electro-acupuncture) in the initial step of ischemic brain injury affects the changes in Bax and Caspase-3 expression among forebrain apoptosis. Methods: It caused GI by using common carotid artery occlusion and conducted the test by dividing into the no applied EA group after 6 hours and 12 hours, the LI 4 EA group that applied EA to LI 4, and GV 20 EA group that was applied to GV 20. After that, the following results were obtained by comparing Bax and Caspase-3 expression, which were apoptosis-related factors, with its application time through immunohistochemical staining after extracting brain of each group. Results: According to each group`s Bax expression by the application time, the order of expression increase after 6 hours is shown to be the no applied EA group, LI 4 group, and GV 20 group. The stimulation after 12 hours was most lowly expressed in the GV 20 group, and the no applied EA group and LI 4 group showed similar level. Conclusions: EA stimulation in the initial step after ischemia seems to affect positively Bax and Caspase-3 expression that are index of forebrain apoptosis.

감마분광분석을 이용한 환경 중 방사성요오드(¹³¹I)의 측정 불확도에 관한 사례 연구

조윤해(Yoon Hae Cho),설빛나(Bitna Seol),민경옥(Kyoung Ok Min),김완석(Wan Suk Kim),이준배(Jun Bae Lee),이수형(Soo Hyung Lee) 大韓環境工學會 2016 대한환경공학회지 Vol.38 No.1

환경에 존재하는 인공방사성핵종 중 방사성요오드(131I)는 주로 갑상선질환의 치료에 사용되며 환자의 배출과정을 통해 체외로 방출된다. 붕괴가 채 끝나지 않은 131I는 환경으로 방출되어 공공수역에서 검출될 수 있다. 본 연구는 공공수역에서 검출된 131I 방사능 결과의 정확도 및 신뢰도에 영향을 미치는 불확도 중 계측 과정에서 발생하는 불확도에 대하여 금강수계의 실제 사례를 조사하였다. 시료는 금강권역 삽교천 수계의 하천수 및 그 상류의 하수처리장 방류수를 대상으로 하였으며, 시료량에 따른 불확도를 확인하기 위하여 각 지점의 시료를 1, 10, 20 L로 채수하였다. 채취한 시료는 시료량에 따라 전처리를 거친 후 1 L 마리넬리 비커에 충전하여 HPGe (High Purity Germanium) 감마선 검출기를 이용하여 10,000초 단위로 계측·분석하여 계측시간 및 방사능에 따른 측정불확도를 비교하였다. 각 지점의 방사능 농도는 0.03~1.8 Bq/L로, 채취시점에 따라 차이가 있는 것으로 나타났다. 131I의 방사능 농도가 0.3 Bq/L 수준인 경우 시료량이 1 L이면 약 80,000초 계측 시까지핵종의 존재여부를 판단하지 못하는 경우가 발생하였으나, 같은 조건에서 시료량을 증가시켜 계측한 경우 10,000초 이상의 계측시간부터 불확도 10% 범위에 포함되는 것으로 나타났다. 131I의 짧은 반감기를 고려하여 즉시 계측이 가능한 1 L 생시료계측 방법을 사용할 수 있으나, 불확도 수준과 전처리 및 계측에 소요되는 시간을 비교하였을 때, 10 L 시료의 계측을 통해 높은 신뢰도의 측정 결과를 얻을 수 있는 합리적인 방법이라고 판단되었다. The radioactive iodine (131I) presents in the environment through the excrete process of nuclear medicine patients. In the detecting of low level of 131I in the public water, the counting uncertainty has an effect on the accuracy and reliability of detecting 131I radioactivity concentration. In this study, the contribution of sample amount, radioactivity concentration and counting time to the uncertainty was investigated in the case of public water sample. Sampling points are public water and the effluents of a sewage treatment plant at Sapkyocheon stream, Geumgang river. In each point, 1, 10 and 20 L of liquid samples were collected and prepared by evaporation method. The HPGe (High Purity Germanium) detector was used to detect and analyze emitted gamma-ray from samples. The radioactivity concentration of 131I were in the range of 0.03 to 1.8 Bq/L. The comparison of the counting uncertainty of the sample amount, 1 L sample is unable to verify the existence of the 131I under 0.5 Bq/L radioactivity concentration. Considering the short half-life of 131I (8.03 days), a method for measuring 1 L sample was used. However comparing the detecting and preparing time of 1, 10 L respectively, detecting 10 L sample would be an appropriate method to distinguish 131I concentration in the public water.

감마분광석을 이용한 공공수역 중 방사성요오드(131l)의 검출불확도에 관한 실험적 연구

조윤해 ( Yoon Hae Cho ),윤조희 ( Jo Hee Yoon ),이재정 ( Jay J. Lee ),설빛나 ( Bit Na Seol ),김완석 ( Wan Suk Kim ),민경옥 ( Kyoung Ok Min ),이준배 ( Jun Bae Lee ),이수형 ( Soo Hyung Lee ) 한국물환경학회(구 한국수질보전학회) 2015 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2015 No.-

DDAVP(1-Desamino-8-D-Arginine Vasopressin)을 이용한 요붕증의 치험 1예

백승곤,민경옥,이동근,최응상,심태섭 중앙대부설한국의과학연구소 1985 한국의과학 Vol.17 No.1

소아의 유행성 출혈열 1예 보고 : 급성 신부전증이 동반된 예 A case with acute renal insufficiency

유경현,민경옥,이동근,유병훈 중앙대부설한국의과학연구소 1985 한국의과학 Vol.17 No.1