GaOOH 선구체의 스핀코팅에 의한 GaN 박막의 성장

이재범,김선태,Lee, Jae-Bum,Kim, Seon-Tai 한국재료학회 2007 한국재료학회지 Vol.17 No.1

GaN thin fan were grown by spin coated colloidal GaOOH precursor. Polycrystalline GaNs with crystalline size of $10{\sim}100nm$ were grown on $SiO_2$ substrate. The shape of crystallite above $900^{\circ}C$ had the hexagonal plate and column type. X-ray diffraction patterns for them correspond to those of the hexagonal wurtzite GaN. With increasing droplets. i.e, thickness of deposited layers, XRD intensity increased. PL (photoluminescence) spectrum consisted with an weak near band-edge emission at 3.45 eV and a broad donor-acceptor emission band at 3.32 eV. From the low temperature PL measurement on GaN grown at $800^{\circ}C$ that the shallow donor-acceptor recombination induced emission was more intense than the near band-edge excitonic emission.

AlOOH로부터 AlN분말의 합성

이재범,김선태,Lee, Jae-Bum,Kim, Seon-Tai 한국재료학회 2006 한국재료학회지 Vol.16 No.12

In this study, we report a method to synthesize the aluminum nitride (AlN) powders from aluminum oxyhydroxide (AlOOH). AlOOH powders were prepared from the aluminum hydroxide ($Al(OH)_3$) by heattreatment at the reaction temperature of $350^{\circ}C$. Simple heat treatment of AlOOH in the flow of $NH_3$ gas leads to the formation of hexagonal AlN powders through intermediate conversion of ${\delta}-,\;{\gamma}-$ and ${\alpha}-Al_2O_3$. The FTIR transmission spectra show a broad peak related to Al-N bonds centered around 690 $cm^{-1}$ confirming the presence of AlN. The major peaks in Raman spectra were observed in 250 $cm^{-1}$ and 659 $cm^{-1}$. From the results, synthesized powders from the AlOOH powders were confirmed AlN powders.

Vapor Transport Epitaxy에 의한 GaN의 성장과 특성

이재범,김선태,Lee, Jae-Bum,Kim, Seon-Tai 한국재료학회 2006 한국재료학회지 Vol.16 No.8

Highly c-axis oriented poly-crystalline GaN with a dimension of $1{\sim}3\;{\mu}m$ was deposited on $c-Al_2O_3$ substrate by vapor transport epitaxy (VTE) method at the temperature range of $900{\sim}1150^{\circ}C$. XRD intensities from (00'2) plane of grown GaNs were increased with reaction conditions which indicate the improvement of the crystal quality. In the PL spectra measured at 10 K, the spectrum composed with the neutral-donor bound exciton-related emission at 3.47 eV, crystal defect-related emission band at 3.42 eV and with its phonon replicas. The fact that intensity of $I_2$ were increased and FWHM were decreased with growth conditions means that the quality of GaN crystals were improved. With this simple VTE technology, we confirm that the GaNs were simply deposited on sapphire substrate and crystal quality related to optical properties of GaN grown by VTE were relatively good. PL emission without deep level emission in spite of polycrystalline structure can be applicable to the fabrication of large area and low cost optical devices using poly-GaN grown by VTE.

딥러닝 기반 가시광 통신 시스템의 성능 향상 기법

서성일,Seo, Sung-Il 한국인터넷방송통신학회 2021 한국인터넷방송통신학회 논문지 Vol.21 No.4

본 논문은 스마트 빌딩을 위한 가시광 통신 시스템에서 데이터 신뢰성을 향상시키는 딥러닝 기반의 간섭 제거 알고리즘에 대해 연구하였다. 본 논문에서 제안한 기법은 딥러닝 기술을 적용하여 채널에서 발생하는 잡음을 예측하여 제거하는 기술로서 수신단에서 딥러닝에 의해 학습된 잡음들을 활용하여 효과적으로 잡음을 제거함으로써 신호의 품질을 향상시킬 수 있다. 딥러닝 기술의 잡음 예측 정확도를 향상시키기 위해 기존의 잡음 형태를 데이터베이스화하여 활용하였다. 모의실험을 통해 간섭 제거 기법이 적용된 시스템 모델의 성능을 검증하였으며, 제안하는 시스템이 잡음을 효과적으로 제거하여 신호의 품질 성능을 향상시킬 수 있음을 확인하였다. 제안한 시스템 모델은 가시광 통신뿐만 아니라 일반적인 통신 시스템에서도 신호의 품질을 향상시킬 수 있도록 다양하게 적용이 가능하다. In this paper, we propose the deep learning based interference cancellation scheme algorithm for visible light communication (VLC) systems in smart building. The proposed scheme estimates the channel noise information by applying a deep learning model. Then, the estimated channel noise is updated in database. In the modulator, the channel noise which reduces the VLC performance is effectively removed through interference cancellation technique. The performance is evaluated in terms of bit error rate (BER). From the simulation results, it is confirmed that the proposed scheme has better BER performance. Consequently, the proposed interference cancellation with deep learning improves the signal quality of VLC systems by effectively removing the channel noise. The results of the paper can be applied to VLC for smart building and general communication systems.

지체장애학생이 지각하는 사회적 지지가 건강관련 삶의 질에 미치는 영향

이재범(Jae Bum Lee),김용국(Yong Kuk Kim) 한국사회체육학회 2010 한국사회체육학회지 Vol.0 No.39

The objective of this study is to explain the effects of social support perceived by students with physical disabilities on their health-related quality of life. For this, we examined differences in social support and health-related quality of life according to the detailed disability type of students with physical disabilities, and tested the multidimensional relations between the sub-factors of social support and health-related quality of life. The subjects of this study were students with physical disabilities at H University in K Province, and we collected the responses of 144 students aged over 20 using a rating scale whose psychometric validity had been tested. According to the results of MANOVA, social support and health-related quality of life in students with physical disabilities were different according to detailed disability type. In addition, the theoretical compatibility of the two variables was confirmed through a structural equation model. Furthermore, when the correlation between the two variables was analyzed through multiple regression analysis, the sub-factors showed high explanatory power for the sub-factors of health-related quality of life, that is, physical function, role limitations, and general health, excluding mental health. Based on these results, we discussed how to provide social support in order to enhance health-related quality of life in students with physical disabilities.

고려 후기 왜구의 성격에 대하여

이재범 ( Jae Bum Lee ) 수선사학회 2003 史林 Vol.19 No.-

논문 : 신숭겸(申崇謙)의 생애(生涯)와 사후(死後) 추숭(追崇)

이재범 ( Jae Bum Lee ) 수선사학회 2013 史林 Vol.0 No.44

Although Sin-Sunggyeom is estimated that he was born in Gokseong[谷城], Cholla province[全羅道] and a member of the powerful family[豪族] with the locally based, people who lived in his time remembered him as a man of Chuncheon[春川]`s origin. And then this memory was recorded on Koryeosa[高麗史] that the central government complied. However this memory was replaced by an opinion that he is a man of Gokseong`s origin as the local memories spread, transmitted to the central government, and was recorded on the local paper. Even if Sin-Sunggyeom was known as a man who was originally ``Im-Hyub[任俠], he seemed a general who had both literary and military arts, and had the local influence power. It may persume that he joined Gungye[弓裔]`s political power by the time Wang-Gun[王建], a commander who served Gungye, was taking southwestern seaboard in korea, in 903. However, when Gungye renamed the name of country as Majin[摩震] and also tried to establish a strong centralized state and to make landed proprietors[豪族] government officials, they came into conflict with Gungye`s political power because they might lose their landed base. It presume that Sin-Sunggyeom[申崇謙] began to be connected with Chuncheon around that time. After Park-Yoo[朴儒] who was a member of the powerful family in Chuncheon fled because of discord with Goongye, the area seemed to be administered by Sin-Sunggyeom. So when Sin-Sunggyeom died in place of the king Taejo[太祖] in Koryeo Dynasty during a battle, Chuncheon seemed to be chosen as his burial ground. Since Sin-Sunggyeom`s loyalty had been passed down up to Chosun Dynasty, a movement for worship of him had constantly done. And his characteristic has been passed down until now beyond time and space. Especially in the late of Chosun Dynasty, the movement for worship expanded to the construction of his temple. The reason that the movement for worship of him as an absolute symbol of loyalty strengthened by spreading the propagation of Sung Confucianism that emphasizes the loyalty and filial piety after the war of the years of Im-Jin[壬辰] and Beong-Ja[丙子] is understood. He had been esteemed for his achievements as a meritorious retainer at the founding of a dynasty and his dead on half of the king Taejoduring Koryeo Dynasty, and had been recognized as a symbol of loyalty like Gisin[紀信] who died in place of the king Kojo [高祖] in Han[漢] Dynasty, China during Chosun Dynasty. His loyalty has been the steadfast object of the respect and admiration in spite of replacement of dynasties.

麗元聯合軍의 日本征伐과 『東方見聞錄』

李在範(Lee, Jae-Bum) 국방부 군사편찬연구소 2003 군사 Vol.- No.50

엑시머레이저각막절제술(PRK)과 레이저각막절삭가공성형술(LASIK) 후 자동굴절검사와 수동굴절검사의 차이 분석

이재범(Jae Bum Lee),이경섭(Kyoung Seob Lee),이동호(Dong Ho Lee),김응권(Eung Kweon Kim) 대한안과학회 1999 대한안과학회지 Vol.40 No.2

弓裔政權의 鐵圓定都 時期와 專制的 國家經營

이재범(Lee Jae-Bum) 한국사학회 2005 史學硏究 Vol.- No.80

궁예정권은 도읍을 철원ㆍ개성ㆍ철원으로 옮겼다. 그러나 처음 철원에 도읍한 896년은 아직 국가체계가 정립되지 않았던 시기였다. 898년에 단행한 송악 천도 또한 국호가 제정되어 있지 않았던 시기로 국도의 이전으로 보기에는 무리가 따른다. 궁예는 904년에 국호와 연호를 바꾸고 청주인호 일천을 철원에 사민하고, 905년에 철원으로 도읍을 옮겼다. 이 과정에서 궁예는 철원을 ‘경’으로 승격시키고 ‘신경’이라고 하였다. 여기서의 경은 다른 도읍과 차별화되는 천자의 도읍지로서의 자격을 갖는 것이었다.<br/> 그리고 궁예는 자신의 웅대한 국가 계획을 철원경에서 실현하고자 한다. 궁예는 관제정비, 관계수립 등의 일련의 제도적 개혁을 통하여 자신의 국가경영의 포부를 확고히 하려 하였다. 궁실을 거창하게 하여 왕의 권위를 높이려고 했다. 궁예는 신분제를 개혁하려는 의지도 보였다.<br/> 궁예는 이러한 원대한 계획을 철원이라는 지리적 공간을 중심으로 수행하려 하였다. 비록 그 과정에서 많은 반대파들을 형성케 하여 자신의 몰락을 자초하기도 했지만, 궁예의 역사적 경험이 이후 고려에 끼친 영향이 적지 않다고 할 것이다. 궁예는 ‘경’을 중부에 설치함으로써 신라 중심의 구도를 철원으로 옮기려는 시도를 하였던 것으로 추정해 볼 수도 있다. 905년의 철원정도는 궁예정권이 천자국으로 출발하는 원년이라고 할 수 있을 것이다. Gungye Regime moved its capital city several times, including the ones from Cheolwon to Gaesung, from Gaesung back again to Cheolwon. But the movement in 896 A.D, was non-systematically made because its national system was not well organized. In 898 A.D., when they moved their capital to Songak, even the name of a new state was not yet made so that it could not adequately be called a proper-type of movement of a capital city. In 904 A.D., Gungye changed both his nation title and his royal year and he settled down 1,000 families of Cheongju to Cheolwon in 905 A.D. In the process, Gungye promoted Cheolwon to a capital-level titled city, calling it "a New Capital City", which was differed from other cities, because it implied that a capital city governed by an emperor.<br/> In this imperial city, Gungye wished to realize his marvellous national program. Through several innovations, including the reorganization of governmental system, and the establishment of novel relationship with neighboring governments, he tried to realize his vision of an ideal state. Building lofty palaces, he wanted to promote a royal status, and he also had a will to renovate the traditional class system.<br/> Gungye wanted to realize several ambitious programs in and around his capital city of Cheolwon. In the process of execution, he met obstacles from political opponents, resulting his own downfall. But his own tragedy put a great influence upon Goryo regime. Gungye's idea to set an imperial city in Cheolwon shows his dream to transform the original power structure, from Shilla-centeredness to Cheolwon- centeredness, as an emperor-governing capital city in the mid-central region of the Korean peninsula. In this respect we must interpret the year 905 A.D., as the first year of Gungye's imperial state.