Surface plasmon-assisted photoluminescence enhancement of Au-hybrid CdSe/ZnS nanocrystal quantum dots

Kim, Inhong,Moon, Jong-Sik,Kyhm, Kwangseuk,Oh, Jin-Woo Informa UK (TaylorFrancis) 2017 Molecular Crystals and Liquid Crystals Vol.654 No.1

<P>We demonstrated that radiative recombination rate of CdSe/ZnS nanocrystal quantum dots is enhanced by local surface plasmon of an adjacent Au layer as a consequence of the Purcell effect. In the presence of Au thin layer, the photoluminescence intensity and the decay rate of CdSe/ZnS nanocrystal quantum dots become significantly enhanced due to the coupling between the excitons of CdSe/ZnS nanocrystal quantum dots and the surface plasmon electric field of Au layer, whereby the Purcell factor (1.6 similar to 2.3) has been obtained as a measure of enhancement.</P>

Recent advances in M13 bacteriophage-based optical sensing applications

Kim Inhong,Moon Jong-Sik,오진우 나노기술연구협의회 2016 Nano Convergence Vol.3 No.27

Recently, M13 bacteriophage has started to be widely used as a functional nanomaterial for various electrical, chemical, or optical applications, such as battery components, photovoltaic cells, sensors, and optics. In addition, the use of M13 bacteriophage has expanded into novel research, such as exciton transporting. In these applications, the versatility of M13 phage is a result of its nontoxic, self-assembling, and specific binding properties. For these reasons, M13 phage is the most powerful candidate as a receptor for transducing chemical or optical phenomena of various analytes into electrical or optical signal. In this review, we will overview the recent progress in optical sensing applications of M13 phage. The structural and functional characters of M13 phage will be described and the recent results in optical sensing application using fluorescence, surface plasmon resonance, Förster resonance energy transfer, and surface enhanced Raman scattering will be outlined.

Radiative decay time as a function of temperature in double GaAs quantum rings

Kim, Heedae,Kim, Jong Su,Kim, Inhong Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.478 No.-

<P><B>Abstract</B></P> <P>This study examined the temperature-dependent, time-integrated/-resolved photoluminescence of the exciton states in double GaAs quantum rings. The density of states was analyzed from the temperature-dependent radiative decay time of exciton states to better understand the intra-relaxation process from thermally excited exciton states. To distinguish the radiative decay time from a non-radiative process, the decay time from the exciton states was calibrated by a comparison with the photoluminescence intensity at low temperatures, where the non-radiative process can be negligible. In ideal quantum ring structures, the ring width becomes almost zero. Therefore, one-dimensional nature would be expected. On the other hand, this assumption is not valid because widthless ring structures cannot be grown using current growth techniques. In other words, the quasi-one-dimensional nature (power order of the temperature dependence from radiative decay times ∼0.8 between 1.0 (two-dimensional nature) and 0.5 (one-dimensional nature)) was observed in quantum ring structures when the ring width was comparable to the radius of the ring structures. In the case of double quantum rings, however, the power order of the temperature dependence was obtained from the radiative decay times, which gave rise to 1.0, corresponding to a two-dimensional nature. This increased dimensional nature can be attributed to the appreciable ring width and ring size, extended wave function due to optical coupling, and the presence of dark exciton states.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The dimensionality of coupled quantum rings was investigated in terms of the radiative decay time as a function of temperature. </LI> <LI> Time-integrated photoluminescence intensity spectra were measured at various temperatures with a spectral redshift in coupled quantum rings. </LI> <LI> The two dimensional density of states was obtained in terms of the power order (α = 1.0) from temperature-dependent radiative decay times. </LI> </UL> </P>

Factors Influencing Suicidal ideation among Korean University Students

Kim, Inhong,Park, Younghee The Institute of Internet 2019 International journal of advanced smart convergenc Vol.8 No.3

Korea has the highest suicide rate among the OECD countries, and the suicide rate is highest among young adults in their 20s, most of whom are university students. Therefore, suicide among Korean university students is a public health issue that is of interest to us. The purpose of this study is to investigate the factors affecting the suicidal ideation of university students in Korea, and to use them as a basis to establish effective intervention for university suicide prevention through it. This was a cross-sectional descriptive study using convenience sampling method. The participants were 344 university students at universities in S and G cities. Data were collected with a structured questionnaire and analyzed using descriptive analysis, t-test, ANOVA, Pearson correlation coefficients, and hierarchical regression analysis using with the SPSS/Win 23.0 program. There was a significant correlation between depression (r=.45, p<.001), drinking alcohol (r=.14, p=.008), social support (r=-.26, p<.001), quality of life (r=-.46, p<.001), and suicidal ideation. In the first step of hierarchical regression analysis, satisfaction of school life (${\beta}=.198$, p<.001) was the significant factor influencing the suicidal ideation. Explanatory power was 25.2%. In the second step of the hierarchical regression analysis, absence of parents (${\beta}=-.095$, p=.044), depression (${\beta}=.247$, p<.001), quality of life (${\beta}=-.280$, p<.001), and explanatory power were increased to 42.0%. The results of the study indicate the need to actively identify the group of university students in their 20s with high risk of suicide through continuous evaluation of depression, and to improve the quality of life as a method of preventing suicide. In addition, the effect of absence of parents on the suicidal ideation among Korean university students suggests that parental support may play an important role in suicide prevention.

Factors Influencing Suicidal ideation among Korean University Students

Inhong Kim,Younghee Park 한국인터넷방송통신학회 2019 Journal of Advanced Smart Convergence Vol.8 No.3

Korea has the highest suicide rate among the OECD countries, and the suicide rate is highest among young adults in their 20s, most of whom are university students. Therefore, suicide among Korean university students is a public health issue that is of interest to us. The purpose of this study is to investigate the factors affecting the suicidal ideation of university students in Korea, and to use them as a basis to establish effective intervention for university suicide prevention through it. This was a cross-sectional descriptive study using convenience sampling method. The participants were 344 university students at universities in S and G cities. Data were collected with a structured questionnaire and analyzed using descriptive analysis, t-test, ANOVA, Pearson correlation coefficients, and hierarchical regression analysis using with the SPSS/Win 23.0 program. There was a significant correlation between depression (r=.45, p<.001), drinking alcohol (r=.14, p=.008), social support (r=-.26, p<.001), quality of life (r=-.46, p<.001), and suicidal ideation. In the first step of hierarchical regression analysis, satisfaction of school life (β=.198, p<.001) was the significant factor influencing the suicidal ideation. Explanatory power was 25.2%. In the second step of the hierarchical regression analysis, absence of parents (β=-.095, p=.044), depression (β=.247, p<.001), quality of life (β=-.280, p<.001), and explanatory power were increased to 42.0%. The results of the study indicate the need to actively identify the group of university students in their 20s with high risk of suicide through continuous evaluation of depression, and to improve the quality of life as a method of preventing suicide. In addition, the effect of absence of parents on the suicidal ideation among Korean university students suggests that parental support may play an important role in suicide prevention.

Exciton Dipole–Dipole Interaction in a Single Coupled-Quantum-Dot Structure via Polarized Excitation

Kim, Heedae,Kim, Inhong,Kyhm, Kwangseuk,Taylor, Robert A.,Kim, Jong Su,Song, Jin Dong,Je, Koo Chul,Dang, Le Si American Chemical Society 2016 NANO LETTERS Vol.16 No.12

<P>We find that the exciton dipole dipole interaction in a single laterally coupled GaAs/AlGaAs quantum dot structure can be controlled by the linear polarization of a nonresonant optical excitation. When the excitation intensity is increased with the linearly polarized light parallel to the lateral coupling direction [1 (1) over bar0], excitons (X-1 and X-2) and local biexcitons (X1X1 and X2X2) of the two separate quantum dots (QD(1) and QD(2)) show a redshift along with coupled biexcitons (X1X2), while neither coupled biexcitons nor a redshift are observed when the polarization of the exciting beam is perpendicular to the coupling direction. The polarization dependence and the redshift are attributed to an optical nonlinearity in the exciton Forster resonant energy transfer interaction, whereby exciton population transfer between the two quantum dots also becomes significant with increasing excitation intensity. We have further distinguished coupled biexcitons from local biexcitons by their large diamagnetic coefficient.</P>

임베디드 시스템에서의 메모리 압축 스왑 기법

김인홍(Inhong Kim),강진구(Jinku Kang),이인환(Inhwan Lee) 한국정보과학회 2010 한국정보과학회 학술발표논문집 Vol.37 No.2B

최근의 모바일 혹은 스마트폰의 운영체제는 과거와 달리 멀티태스킹의 지원과 효율적인 메모리 관리를 위하여 가상 메모리 기법을 사용한다. 하지만 그 대가로 페이지 폴트를 발생시킨다. 페이지 폴트가 발생되고 여유 메모리가 설정된 임계 값보다 부족하게 되면 운영체제가 메모리에서 사용되지 않는 페이지를 찾아서 디스크로 스왑 하여 여유 공간을 확보하게 된다. 본 논문에서는 주 메모리의 일부를 압축하여 스왑 영역으로 설정하여 스왑아웃 시 페이지를 압축하여 압축영역에 저장하고 스왑인시 압축을 해제하여 주 메모리로 불러오는 압축 시스템을 구현 평가하였다.

물 및 시비관리 방법에 따른 논에서의 영양물질 수지 모니터링

김계웅 ( Kyeung Kim ),강문성 ( Moon Seong Kang ),송인홍 ( Inhong Song ),송정헌 ( Junghun Song ),김진수 ( Jin Soo Kim ),장정렬 ( Jeong-ryeol Jang ) 한국농공학회 2014 한국농공학회 학술대회초록집 Vol.2014 No.-

새만금 유역의 비점오염원 배출부하량은 농업비점오염원에 의한 오염이 전체 오염의 40 ∼ 60%에 달하는 것으로 보고되고 있으며, 농경지 비점오염원 관리의 필요성이 증가하고 있다. 농경지에서 배출되는 비점오염원은 물리적 특성뿐만 아니라 물 및 시비관리 등 영농방법에 영향을 받기 때문에 영농방법을 고려하여 비점오염원을 관리하는 것이 중요하다. 본 연구에서는 새만금 유역의 논을 대상으로 물 및 시비관리 시험포를 구축하고, 수문·수질 모니터링을 하여 논에서의 영양물질 수지를 비교·평가하고자 한다. 본 연구의 연구대상지로 익산천 유역 하류에 위치한 전라북도 익산시 춘포면 용연리을 선정하였고, 시험 포장의 크기는 110 m × 35 m (3,850m²)이며 총 6개로 구성되어 있다. 본 연구의 대조구는 새만금 유역에서 적용되는 관행 영농방법을 적용하는 시험포로, 처리구는 물꼬높이를 12 cm로 높여 관리하는 시험구 (물관리구) 및 완효성 비료를 시비하는 시험구(시비관리구)로 구성하였으며, 각 처리구별로 2반복하였다. 모니터링은 2013년 영농기간 동안 수행하였으며, 관개량, 배수량 등의 수문모니터링과 강우시 및 비강우시 수질모니터링을 실시하였다. 수질분석은 서울대학교 농업생명과학공동기기원 (NICEM)에 의뢰·분석하였다. 연구결과 관행구의 T-N 배출부하량은 평균 1.55 kg/10a, 물관리구는 1.17 kg/10a, 시비관리구는 0.85 kg/10a로 나타나 관행구에 비해 물관리구는 약 24%, 시비관리구는 약 45% 저감되는 것으로 나타났다. T-P배출부하량의 경우 관행구는 평균 0.14 kg/10a, 물관리구는 0.10 kg/10a, 시비관리구는 0.07 kg/10a로 나타나 관행구에 비해 물관리구는 약 26%, 시비관리구는 약 49% 저감되는 것으로 나타났다.

CREAMS를 이용한 비영농기 논 배출부하량 추정

김민지 ( Minji Kim ),강문성 ( Moon Seong Kang ),송인홍 ( Inhong Song ),김계웅 ( Kyeung Kim ),송정헌 ( Jung-hun Song ),장정렬 ( Jeong Ryeol Jang ) 한국농공학회 2015 한국농공학회 학술대회초록집 Vol.2015 No.-

수질오염총량제가 실시됨에 따라 정확한 오염부하량 산정을 위해, 토지이용별 정확한 원단위를 추정하는 것이 중요하게 되었다. 논은 우리나라 총 면적의 약 9.3%를 차지하고 있어, 오염총량을 추정하는데 있어 큰 비중을 차지하고 있다. 그러나 논 배출부하와 관련된 연구는 영농활동이 이루어지는 5월 ~ 9월까지 집중되어 있으며, 상대적으로 1년의 약 50%를 차지하는 비영농기에 대한 배출부하 연구는 미흡하게 이루어지고 있어, 연 단위의 배출부하를 추정하는 것에는 어려움이 있다. 본 연구에서는 농업지역 포장단위 모형인 CREAMS(Chemicals, Runoff, and Erosion From Agricultural Management Systems)를 이용하여, 비영농기 동안 논에서의 배출부하를 모의하고, 논에서의 연 단위 배출부하를 추정하고자 한다. 대상지구로는 영농기 동안 수문·수질 모니터링이 실시된 전라북도 익산시 춘포면의 논포장을 대상으로 하였으며, 모형의 구동에 필요한 토양 특성 자료는 서울대학교 농업생명과학공동기기원 (NICEM)에 위탁하여 분석된 자료를 이용하였다. 기상 자료는 포장과 인접한 전주 기상대의 일사량 및 평균기온과 대상 지구에서 관측한 일강우량 자료를 사용하였다. 본 연구의 결과는 비영농기를 고려한 연 단위의 논 배출부하를 추정하는데 도움이 될 것으로 사료된다.

공력 저항 측정기를 이용한 방풍펜스 방진막의 공기 투과 저항력 측정

김락우,이인복,홍세운,황현섭,손영환,김태완,김민영,송인홍,Kim, Rack-Woo,Lee, In-Bok,Hong, Se-Woon,Hwang, Hyun-Seob,Son, Young-Hwan,Kim, Tae-Wan,Kim, Min-Young,Song, Inhong 한국농공학회 2013 한국농공학회논문집 Vol.55 No.6

Recently, damage occurrence by wind erosion has been increasing in society. In times past, such problems only took place in desert area ; however, in recent years, the wind erosion problem is spreading out to agricultural land. Wind erosion in agricultural land can cause loss of loam soils, the disturbance of the photosynthesis of the crop fields and serious economic losses. To overcome the mentioned problems, installation of windbreak fence can be recommended which function as disturbing strong wind and wind erosion. However, there is still no proper guideline to install the windbreak fence and the installation used to rely on the intuition of the workers due to the lack of related studies. Therefore, this study measured the aerodynamic resistance of screens of the windbreak fence using the apparatus for testing screens. The apparatus for testing screens was designed to measure pressure loss around the screen. Measured pressure loss by wall friction compensated for pressure loss to calculate the aerodynamic resistance of screens. The result of pressure loss by regression analysis derived the aerodynamic coefficient of Darcy-Forchheimer equation and power law equation. The aerodynamic resistance was constant regardless of the overlapped shape when the screen was overlapped into several layers. Increasing the number of layers of the screen, internal resistance increased significantly more, and pressure loss caused by the screen also increased linearly when the wind speed was certain conditions, but permeability had no tendency. In the future, the results of this study will be applied to the computational fluid dynamics simulation. The simulation models will be also validated in advance by wind tunnel experiments. It will provide standard of a design for constructing windbreak fence.