새로운 방식의Complementary Code Keying Orthogonal Frequency Division Multiplexing (CCK-OFDM) 무선랜 모뎀에 관한 연구

정원정,박현철 한국통신학회 2004 韓國通信學會論文誌 Vol.29 No.8C

본 논문에서는 변수 3개를 가지는 1차 리드뮬러 (Reed-Muller: RM(1, 3)) 코드를 이용하여 보수 코드 키잉(Complementary Code Keying: CCK)방식의 8칩을 동일하게 생성하는 것을 보였다. 여기서 CCK 코드워드는 하나의 에러 정정이 가능하고, 평균 전력 대 최대 전력 비 (Peak-to-Average Power Ratio: PAPR)가 2인 골레이 시퀀스 (Golay Sequence)이다. 이러한 RM 코드 성질을 이용하여 우리는 CCK방식과 직교 주파수 분할 다중(Orthogonal Frequency Division Multiplexing: OFDM) 시스템 방식을 동시에 사용하는 무선랜 모뎀을 제안하였다. 제안된 시스템을 바탕으로 RM 코드 변수가 4개로 확장, 즉 RM(1, 4)를 적용 시, 성능이 개선되고 OFDM 시스템에서 큰 문제점인 PAPR이 최대 9㏈이하로 나타남을 살펴보았다. 일반적으로 RM(1, 4)를 위해서 수신부에서는 16 256 크기의 고속 하다마드 변환 (Fast Hadamard Transform: FHT) 행렬이 필요하지만, 제안된 시스템에서는 성능 열화 없이 8 64와 2 4 크기의 FHT행렬을 각각 하나씩 사용하여 그 복잡도 (Complexity)를 줄일 수 있다. 일반화된 형태로서RM 코드의 변수가 증가하더라도 수신부의 복잡도는 증가하지 않고, 성능 및 PAPR 개선의 효과를 가질 수 있다. In this paper, we show the equivalence between complementary code keying (CCK) codeword and coset of the first order Reed-Muller (RM) code with variables of three. The CCK codewords are Golay sequences which have peak-to-average power ratio (PAPR) of two at most and can correct one error. We propose a CCK-orthogonal frequency division multiplexing (OFDM) modem to reduce PAPR. Also, we present the performance improvement techniques by increasing the variables of four to correct three errors and reduce PAPR at least 9㏈ with this system. Although, two Fast Hadamard Transform (FHT) blocks of size 8 64 are required at the receiver, we reduce the complexity by using FHT blocks of size 8 64 and 2 4 without deteriorating the performance. We generalize our results that we may increase the variables of RM code to enhance the error correcting and PAPR reduction capabilities without increasing receiver's complexity.

Eosinophilic Otitis Media: CT and MRI Findings and Literature Review

정원정,이정현,임현경,윤태현,조경자,백정환 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.3

Eosinophilic otitis media (EOM) is a relatively rare, intractable, middle ear disease with extremely viscous mucoid effusion containing eosinophils. EOM is associated with adult bronchial asthma and nasal allergies. Conventional treatments for otitis media with effusion (OME) or for chronic otitis media (COM), like tympanoplasty or mastoidectomy, when performed for the treatment of EOM, can induce severe complications such as deafness. Therefore, it should be differentiated from the usual type of OME or COM. To our knowledge, the clinical and imaging findings of EOM of temporal bone are not well-known to radiologists. We report here the CT and MRI findings of two EOM cases and review the clinical and histopathologic findings of this recently described disease entity.

Measurement of the keV-Neutron Capture Cross-Sections and Capture Γ-Ray Spectra of 155Gd and 157Gd

정원정,김규연,Masayuki Igashira,이삼열,노태익,Toshiro Ohsaki 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.2

The neutron capture cross-sections and the capture $\gamma$-ray spectra of $^{155}$Gd and $^{157}$Gd were measured at the 3-MeV Pelletron accelerator of the Research Laboratory for Nuclear Reactors at the Tokyo Institute of Technology in the energy range from 10 to 550 keV. Pulsed keV-neutrons were produced from the $^7$Li(p,n)$^7$Be reaction by bombarding the lithium target with the 1.5-ns bunched proton beam from the Pelletron accelerator. The spectrum for the neutrons incident on a capture sample was measured by means of a time-of-flight method with a $^6$Li-glass detector. Capture $\gamma$-rays were detected with a large anti-Compton NaI(Tl) spectrometer by employing a time-of-flight method. A pulse-height weighting technique was applied to the observed capture $\gamma$-ray pulse-height spectra to derive the capture yields. The neutron capture cross-sections were determined relative to the standard capture cross-section of $^{197}$Au. The results were compared to other measurements and the evaluated values. The capture $\gamma$-ray spectra were obtained by unfolding the observed capture $\gamma$-ray pulse-height spectra.

Imaging Findings in a Case of Mixed Acinar-Endocrine Carcinoma of the Pancreas

정원정,변재호,이승수,이문규 대한영상의학회 2010 Korean Journal of Radiology Vol.11 No.3

Mixed acinar-endocrine carcinoma (MAEC) of the pancreas is extremely uncommon. We report here a rare case of MAEC of the pancreas presenting as watery diarrhea. This is the first report in the English-language literature that describes the imaging findings of MAEC of the pancreas, including computed tomography (CT), magnetic resonance (MR) imaging, and MR cholangiopancreatography features.

고전기저항용 granular film의 자기적 특성과 자구 관찰

정원정,이영민,이찬규,구본흔,Y.Shimada 한국자기학회 2005 한국자기학회 학술연구발표회 논문개요집 Vol.15 No.1

미용분야에서 인터넷을 이용한 정보의 활용

정원정 한국미용학회 2001 한국미용학회지 Vol.7 No.1

In a modem society of information, because the collection and search of information and use of data through a computer could contribute greatly toward research and development efforts and decision-making by providing data quickly and accurately, a number of countries have focused their efforts in creating the Super Information Highway. Korea became a member of this effort since t990 and has been taking advantage of diverse information resources to a point where a number of Internet users in Korea is expected to surpass 20 million during the first quaver of 2001, as reported by Korea Network Information Center(KRNIC), In addition, the government announced the 'Comprehensive Super Information Highway Plan for the 21st Century' with a focus on application service developments such as remote learning(Web-based education) and Electronic Library by accommodating and developing educational research and private research computer networks by year 2015. Because all computers connected to the Internet use a common communication scheme called TCP/IP Protocol, information can be exchanged even among computers of different kinds. As Internet supports diverse services that provide necessary information in a convenient fashion, it is being used mast widely as an academic information network around the world. In other words, on the Internet, one can collect various information through electronic newspapers and magazines(webbing), among other things, and consume programs provided by Internet radio or TV. In addition, an information exchange is possible with people in Unrelated field via electronic mail(e-mail), Usenet, acid Internet chatting, Thus, by utilizing various service features being provided through the Internet effectively, Use information search and efficiency of information utilization for beauty and cosmetics area need to be enhanced. Therefore, this thesis was written to provide W sic information about methods through which network, including internet, can be utilized efficiently for beauty and cosmetics area and would introduce real-life examples of information usage through information and telecommunication networks being attempted in education and research related to beauty and cosmetics.

^(157,158)Gd의 keV-중성자 포획감마선과 포획단면적 측정

정원정,황정훈,김현,노태익 동아대학교 부설 기초과학연구소 2004 基礎科學硏究論文集 Vol.21 No.1

The neutron capture gamma-rays and capture cross-sections of ^(157,158)Gd were measured in a neutron energy region from 10 to 85 keV using the 3mv Pelletron accelerator of Tokyo Institute of Technology. Pulsed neutrons were produced from the ^(7)Li(p,n)^(7)Be reaction. The incident neutron energy on a capture sample was measured by means of a TOF method with a ^(6)Li-glass detector. The capture gamma-rays were detected with a large anti-Compton NaI(Tl) spectrometer. A pulse-height weighting technique was applied to measured capture gamma-ray pulse-height spectra to derive capture yields. The capture cross sections were obtained by using the standard capture cross-section of ^(197)Au. The present results are compared with the previous measurements and the evaluated data of ENDF/B-VI.

The Effect of Family Background on Objective and Subjective Inequality among Young Adults in China, Taiwan, Japan and South Korea

정원정 한국사회학회 2016 한국사회학회 사회학대회 논문집 Vol.2016 No.12

In this research, I first explore the inequality structure in East Asia and analyze the degree of class crystallization in different age groups, using the data from ISSP 2009. In this paper, class crystallization indicates that inter-generational transmission of socioeconomic status is substantial. In the regression analysis of individual’s income on parents’ occupational status, the effect was significant in young age group only in Taiwan, Japan, and in South Korea, controlling other variables including education. This effect was shown only in older age groups in China. Furthermore, when parents’ background effect on individual’s perception of inequality was tested, it turned out to be significant only in Korea. That is, young Koreans from richer family background tend to think their society is more equal. It appears that only in Korea young age group’s perception is being affected by their family background, although class mobility seems to have decreased in Japan and in Taiwan also. As the last part of my research, I bring in the economic history of East Asia in order to interpret this result properly. Finally, I attempt to give an explanation why only South Korea shows such divergence in perception.

^(155,156)Gd 동의원소의 keV 영역 중성자 포획단면적 측정

정원정,황정훈,김현,노태익 東亞大學校 2004 東亞論叢 Vol.41 No.-

The Neutron Capture Cross-Section of ^(155,156)Gd were measured in a neutron energy region from 15 to 85 keV using the 3MV Pelletron accelerator of Tokyo Institute of Technology. Pulsed neutrons were produced from the ^(7Li)(p,n)^(7)Be reaction. The incident neutron spectrum on a capture sample was measured by means of a TOF method with a ^(6)Li-glass detector. The capture γ-ray were detected with a large anti-Compton NaI(TI) spectrometer. A pulse-height weighting technique was applied to measured capture γ-ray pulse-height spectra to derive capture yields. The capture cross sections were obtained by using the standard capture cross-section of ^(197)Au. The present results are corrected for isotope impurities of sample because the samples contain various isotope Godolinium. The present results are compared with the previous measurements and the evaluated data of ENDF/B-VI.

삼중시기 나선식 CT에서 간문맥전 유무에 따른 결절성 간세포암과 종괴형 간세포암의 조영증강양상의 비교

정원정 대한영상의학회 1997 대한영상의학회지 Vol.36 No.6