실내 미세먼지 및 공기질 관리 방법에 대한 국민의 인식 및 행동

이건희,박인용,김상복,홍기정,박대훈,이예완,윤홍식,민태진,김학준,김용진,정상현,한방우 한국냄새환경학회 2021 실내환경 및 냄새 학회지 Vol.20 No.4

Indoor air quality management is essential for a healthy life. However, it is difficult to perceive, detect, and monitor the level of indoor air pollution and this means that it is possible to be exposed to more pollution indoors than outdoors. In this study, in order to derive effective indoor air quality management measures, public perceptions and behavioral characteristics regarding indoor particulate matter and air quality management methods were investigated through a survey of 1,000 people. Based on the survey, it was found that most of the respondents had a negative perception of the indoor air quality of their residence, and natural ventilation was the most used method for indoor air quality management. Although the frequency of use of air quality management devices such as air purifiers and mechanical ventilation systems was relatively low, their effect regarding air quality management was positively perceived. In particular, the results of survey indicated that respondents of families which included members with fragile health engaged in more active behavior regarding in indoor air quality management than those respondents whose family members had no health issues and that the former have used air quality management devices more frequently. Therefore, it is necessary to develop proper guidelines to encourage more people to actively participate in improving indoor air quality.

세계동향 - 영국의 원전 건설과 시사점

이건희,류재수,김미진,Lee, Geon-Hui,Ryu, Jae-Su,Kim, Mi-Jin 한국원자력산업회의 2017 원자력산업 Vol.37 No.11

A Study on the Performance Comparison of 3D File Formats on the Web

이건희,Pyeongho Choi,남정환,Hwa-seop Han,이승현,권순철 한국인터넷방송통신학회 2019 Journal of Advanced Smart Convergence Vol.8 No.1

3D file formats typically include OBJ (Wavefront file format), STL (STereoLithography), and FBX (Filmbox). Each format has limitations depending on its configuration and usage, and supported formats are different depending on the software application. glTF helps uniform integration of 3D file formats and allows for more efficient transmission of large 3D geometry files by organizing them in a binary format. This paper presents explanation on OBJ, FBX, and STL which are major examples of existing 3D file formats. It also explains the concept and characteristics of glTF and compares its performance with other 3D file formats on the web. The loading time and packets of each 3D file format are measured according to the web browser environment by means of Google Chrome, Firefox and Microsoft Edge. Experimental results show that glTF is the most efficient and that it exhibits the best performance. As to STL, relatively excessive traffic was observed. This study is expected to contribute to reducing rendering time on the web as 3D file formats are used.

ROBUSTLY SHADOWABLE CHAIN COMPONENTS OF C¹ VECTOR FIELDS

이건희,Le Huy Tien,Xiao Wen 대한수학회 2014 대한수학회지 Vol.51 No.1

Let γ be a hyperbolic closed orbit of a C¹ vector field X on a compact boundaryless Riemannian manifold M, and let Cχ(γ) be the chain component of X which contains γ. We say that Cχ(γ) is C¹ ro- bustly shadowable if there is a C¹ neighborhood U of X such that for any Y ∈ U, Cr(γr ) is shadowable for Y₁, where γr denotes the continuation of γ with respect to Y. In this paper, we prove that any C¹ robustly shad- owable chain component Cχ(γ) does not contain a hyperbolic singularity, and it is hyperbolic if Cχ(γ) has no non-hyperbolic singularity.

다이오드로 펌핑하는 능동형 Q-스위칭 및 모드-동기된 1064 nm Nd:YAG 레이저와 LBO를 이용한 외부공진기 주파수 배가에 의한 532 nm 레이저의 출력특성

이건희,추한태,박차곤,이형만 한국물리학회 2017 새물리 Vol.67 No.4

The output characteristics of a diode-pumped actively Q-switched and mode-locked (QML) 1064 nm Nd:YAG laser with a Z-type cavity and of an extracavity frequency-doubled 532 nm QML laser with a Lithium Triborate (LBO) were invesgated. At a Q-switching repetition rate of 2 kHz and an incident pump power of 10.5 W, the maximum output powers of a Q-switched laser and a QML laser, both at 1064 nm were 1.21 W and 1.0 W corresponding to optical conversion efficiencies of 11.5\% and 9.5\%, respectively. Also, the pulse widths of the Q-switched envelope and the mode-locked pulse inside the Q-switched envelope at 78 MHz were 215 ns and 990 ps, respectively. The maximum peak power of the only Q-switched and QML laser was 2.8 kW and 10 kW, respectively. In the case of two, the maximum conversion efficiencies of second harmonic generation (SHG) with a LBO were 14\% and 35.5\% corresponding to maximum output powers of 170 mW and 330 mW, respectively. The $M^2$ of a 532 nm QML laser about the x-axis and the y-axis at 532 nm were 2.25 and 2.58, respectively. 다이오드 펌핑하고 동시에 능동형 Q-스위칭 및 모드-동기된(Q-switched and mode-locked, QML) Z-자 형태의 공진기 구조를 갖는 1064 nm Nd:YAG 레이저와 LBO를 이용한 외부공진기 주파수 배가에 의한 532 nm 레이저의 출력 특성을 조사하였다. Q-스위칭 반복률이 2 kHz에서 다이오드 입사 펌프 파워가 10.5 W일 때, Q-스위칭만 된 레이저 경우와 QML 레이저인 경우에 대한 기본파 1064 nm 레이저의 최대 출력은 각각 1.2 W 및 1.0 W이었고, 이에 대응하는 광변환 효율은 각각 11.4\% 및 9.5\%이었다. 또한, Q-스위칭 포락선 및 Q-스위칭 포락선 내에 78 MHz로 모드-동기된 펄스폭은 각각 215 ns 및 990 ps이었으며, 최대 피크 파워는 각각 2.8 kW 및 10 kW로 측정되었다. 두 경우, LBO를 이용한 외부공진기 주파수 배가에 의한 제 2 조화파로의 최대 변환 효율 및 최대 출력은 각각 14\%와 35.5\% 및 170 mW와 330 mW로 측정되었으며, 532 nm QML 레이저의 x-축과 y-축에 대한 $M^2$는 각각 2.25 및 2.58로 측정되었다.

개방적 탐구를 강조한 탐방 활동에서 나타난 초등과학 영재학생들의 활동 과정 분석

이건희,김선자,박종욱 韓國英才學會 2009 영재교육연구 Vol.19 No.1

과학 탐방 학습은 학생이 스스로 문제를 해결할 수 있는 종합적 학습 활동으로 영재 학습에서의 중요성이 강조되고 있다. 그러나 너무 많은 양의 과제를 해결하거나, 정해 진 답을 요구하는 수렴적 활동이 주로 이루어져 영재학생의 능력을 개발하는데 부족하 다는 비판을 받고 있다. 따라서 이 연구에서는 과학영재의 지적 특성을 반영하기 위하 여 개방적 탐구를 토대로 하는 탐방 프로그램을 고안하였다. 이를 초등 과학 영재학생 18명을 대상으로 적용하였고, 탐방 활동지, 상호작용 녹음내용, 발표용 포스터, 설문지 등의 자료를 바탕으로 탐구문제 설정 유형 및 탐구 과정, 탐방 활동 중에 나타나는 과 학 영재의 활동 과정을 분석하였다. 연구결과 탐방 전보다 탐방 후에 더 많은 탐구문제 를 만들 뿐만 아니라 탐구문제의 수준도 더 높아졌다. 이를 해결하는 탐구과정은 계획 하기, 탐구 수행하기, 후속 탐구하기, 정리하기의 순서에 의해 순환적으로 이루어졌으 며, 상황에 따라 다음 단계를 결정하는 개방적 탐구 과정으로 진행되었다. 학생들의 문 제해결 과정에서 기초 탐구과정 및 통합 탐구과정 요소가 다양하게 나타났으며, 특히 결과를 해석하고 변환하여 분석하는 능력이 뛰어났다. 또한 탐방 활동 중에 나타난 학 생들의 상호 작용을 분석한 결과 과학 영재의 행동적 특성이 다양하게 나타났다.

전자어음 이용이 중소기업의 유동성에 미치는 영향

이건희,이기환,서지용 사단법인 한국신용카드학회 2018 신용카드리뷰 Vol.12 No.2

Electronic Promissory Note (EPN) is used as a payment method among enterprises in place of Paper Note or cash. EPN is more safe and clear electronic note to pay amount in 3 months on the average, which are managed and checked by computer system in Korea Financial Telecommunications & Clearings Institute managed by Korean government. Recently, the amount of EPN increases. We researched the relation of EPN usage with cash holding of SMEs by regressions in Korea. As a result, we found that the volume of EPN of each company is related to the cash holding positively in SMEs. That is because SMEs are preparing cash to settle the EPN amount not to be failed. Futhermore, as a result of analysis on the this paper, the bigger the SMEs are, the more cash holding they hold, because the transaction amounts are larger than smaller SMEs. The SMEs are not familiar with borrowing money in the financial market and keep cash settlement for EPN amount and liquidity level, although cash doesn't give earning in SMEs. 본 연구는 중소기업의 보편적인 자금결제수단인 전자어음 거래가 중소기업의 현금보유 중심의유동성에 미치는 영향을 실증적으로 분석한다 . 분석결과 전자어음 이용실적은 중소기업의 현금보유에 통계적으로 유의한 정 (+) 의 영향을 미치는 것으로 나타났다 . 이러한 결과는 전자어음 발행으로 외상거래를 한 후 그 결제를 위한 현금 보유가 증가하기 때문으로 볼 수 있다 . 즉 현금을 보유하여야 어음을 결제할 수 있고 어음부도를 방지할 수 있기 때문이다 . 또한 전자어음의 이용이 증가할수록 중소기업 유동성이 높게 나타나는 바 , 이는 유동자산인 현금 혹은 단기 채권이 결제에대비하여 준비된다는 의미이다 . 또한 , 기업의 재무적 특성요인인 기업규모의 경우에도 통계적 유의성을 보였는데 , 상대적으로 매출액 규모가 큰 중소기업의 경우 현금보유수준이 높은 것을 알 수있다 . 이와 같이 전자어음 발행으로 외상거래를 한 후 그 결제를 위하여 현금을 보유하는 것은 일정기간 중소기업에 자금상의 이익을 주고 있다 .

알레르기비염환자 코점막 상피세포에서 IL-4, IL-13, TNF-α 자극에 의한 Thymus and Activation-Regulated Chemokine의 발현

이건희,김성완,신승엽,조중생 대한비과학회 2008 Journal of rhinology Vol.15 No.2

Background:Thymus and Activation-Regulated Chemokine (TARC) is a highly specific ligand for CCR4 expressed in Th2 lymphocytes. Local production of TARC may play an important role in the induction and maintenance of allergic inflammation with the infiltration of Th2 lymphocytes. However, the cellular sources of TARC among patients with allergic rhinitis (AR) remain unclear. Objective:We investigated that nasal epithelial cells from AR could produce TARC and that they could produce TARC differently by various stimulation of cytokines. Methods:Inferior turbinate mucosal tissues were collected from six patients with AR sensitized to house dust mite. Nasal epithelial cells were isolated, cultured and stimulated with IL-4, IL-13 or TNF-a alone or in combination. The level of TARC in the supernatant was measured by ELISA and mRNA expression of that in the cells by RT-PCR. Results:The level of TARC from cultured nasal epithelial cells (CNEC) among allergic rhinitis patients was higher than that in the control group. IL-4 or IL-13 or TNF-a alone did not upregulate TARC production from CNEC. However, Th2 cytokines in combination with TNF-a increased the production of TARC in CNEC. Conclusion:IL-4, IL-13 and TNF-a could upregulate TARC production from nasal epithelial cells in allergic rhinitis and contribute to the infiltration of Th2 cells to the tissue during allergic inflammation. Background:Thymus and Activation-Regulated Chemokine (TARC) is a highly specific ligand for CCR4 expressed in Th2 lymphocytes. Local production of TARC may play an important role in the induction and maintenance of allergic inflammation with the infiltration of Th2 lymphocytes. However, the cellular sources of TARC among patients with allergic rhinitis (AR) remain unclear. Objective:We investigated that nasal epithelial cells from AR could produce TARC and that they could produce TARC differently by various stimulation of cytokines. Methods:Inferior turbinate mucosal tissues were collected from six patients with AR sensitized to house dust mite. Nasal epithelial cells were isolated, cultured and stimulated with IL-4, IL-13 or TNF-a alone or in combination. The level of TARC in the supernatant was measured by ELISA and mRNA expression of that in the cells by RT-PCR. Results:The level of TARC from cultured nasal epithelial cells (CNEC) among allergic rhinitis patients was higher than that in the control group. IL-4 or IL-13 or TNF-a alone did not upregulate TARC production from CNEC. However, Th2 cytokines in combination with TNF-a increased the production of TARC in CNEC. Conclusion:IL-4, IL-13 and TNF-a could upregulate TARC production from nasal epithelial cells in allergic rhinitis and contribute to the infiltration of Th2 cells to the tissue during allergic inflammation.

화장이 노년기 여성의 우울감에 미치는 영향

이건희,한보현 한국니트디자인학회 2012 패션과 니트 Vol.10 No.2

In modern society elderly people are excluded in labor market by compulsion or voluntarily. They've lost their role in family life due to nuclearizing and this has caused an increase in the number of woman with depression. There are various factors contributing to this such as: elderly people have health problem, partner's passing, economical factors, social isolation and being out of control to daily life and they feel a high degree depression due to these problems. In this study I collected data regarding older women's make-up style and their depression then I investigated the influence of make-up for older women's depression. I used GDS-K; (Geriatric Depression Scale-Korea) before and after make-up was given to 91 old women in Seoul and Gyonggi. The results will follow. The first fact of analysis for make-up is that 71 people among 91 like to wear lipstick, eyeshadow and eyebrow all together, but they only wear lipsticks. The second fact of analysis for depression of elderly women is that the average is 22.86 which means a serious depressive state. The third fact of analysis for influence of make-up for older women's depression is that I fond reduce of depression from an in-depth depression to normal average after make up.

테니스 플랫서브 시 스텐스 유형에 따른 지면반력 및 근전도 요인 분석

이건희,정익수,이진 한국스포츠학회 2017 한국스포츠학회지 Vol.15 No.4

This research analyzed the kinetic variables using GRF & EMG of tennis Flat serve stances; To achieve its purpose, this study analyzed the kinetic variables, Using two GRFs, the Fx, Fy, Fz, and Fr of ground reaction force were analyzed. Moreover, the muscular activity volume of vastus medials, vastus lateralis, tibialis anterior and gastrocnemius were analyzed using EMG. Among the various skills to succeed in performing a precise and strong flat serve, training the ideal stance suited for each individual player is one of the essential factors for the Korean athletes to level with the world-class athletes. Analyzing the GRF, in the Platform stance, the right foot took on a large force in terms of all Fx, Fy, Fz and Fr. When jumping, both right and left foot received the maximum ground reaction in the Platform stance yet the GRF is larger in Pinpoint stance as the right foot is closely put to the left foot. Related to the electromyography, there were significant differences between the Pinpoint and Platform stances. Looking at the muscular activity volume of each stage, both the Pinpoint and Platform stances showed the most muscular activity volume in the left vastus medials in E1 and in the right tibialis anterior in E2. In E3, the right gastrocnemius during the Pinpoint and the left vastus medials during the Platform showed the most muscular activity volume. In E4, both stances displayed the most muscular activity volume in the right gastrocnemius. 본 연구는 테니스 플랫서브 시 스텐스 유형에 따른 지면반력 및 근전도 분석을 실시하였으며, 연구목적을 달성하기 위해 지면반력의 Fx, Fy, Fz 및 Fr을 측정하여 분석하였고, 또한 EMG를 이용하여 내측광근, 외측광근, 전경골근, 비복근의 근육 활동량을 분석 하였다. 정확하고 강력한 플랫 서비스를 성공적으로 수행하는 데 필요한 다양한 기술 중에서도 각각의 선수에게 적합한 이상적인 자세를 훈련하는 것은 한국 선수가 세계 정상급 선수로 성장하는데 필수적인 요소로 판단된다.연구결과 플랫폼 스탠스에서는 Fx, Fy, Fz, Fr 값에서 모두 오른발에서 크게 나타났으며, 왼발과 같이 최대 지면반력을 얻어 점프하는 것으로 나타났다. 핀 포인트 스탠스에서는 왼발에 오른발을 붙여 점프하므로 플랫 폼 스탠스 보다 지면반력이 큰 것으로 나타났다. 근전도와 관련하여 두 스텐스 사이에는 유의한 차이가 있었다. 근전도 요인과 관련하여 E1국면과 E4국면에서 유의한 차이가 나타났으며, 전 국면에서 핀 포인트가 총 근 활성도가 높게 나타났으며, E1국면에서 두 스탠스 모두 좌측 내측광근, E2국면에서는 우측 전경골근, E3국면에서는 플랫폼 우측 비복근, 핀 포인트는 좌측 내측광근, E4국면에서는 두 스탠스 모두 우측 비복근에서 근 활성도가 가장 높은 것으로 나타났다.