객체지향 소프트웨어 스래드 테스팅을 위한 구성 개체의 종속관계 정보 모델

김희득(Heedeuk Kim),윤창섭(Changsup Yoon) 한국정보과학회 1996 한국정보과학회 학술발표논문집 Vol.23 No.2B

객체지향 소프트웨어의 스래드 테스팅을 위하여 스래드에 연결된 객체별로 테스트 케이스를 생성 해야 한다. 정확한 테스트 케이스 생성을 위해서는 테스트 시나리오에 적합하게 스레드에 연결된 객체의 사전 및 사후상태를 설정 해야한다. 본 논문은 프로그램에대한 EDG(Entity Dependency Graph)를 작성하고, EDG를 분석하여 클래스자원간의 종속관계에 대한 정보를 생성 제공하기 위한 방법을 제안 한다.

Large Brillouin amplification in silicon

Kittlaus, Eric A.,Shin, Heedeuk,Rakich, Peter T. Nature Publishing Group, a division of Macmillan P 2016 Nature photonics Vol.10 No.7

<P>Both Kerr and Raman nonlinearities are radically enhanced by tight optical-mode confinement in nanoscale silicon waveguides(1-4). Counterintuitively, Brillouin nonlinearities-originating from coupling between photons and acoustic phonons-are exceedingly weak in these same nonlinear waveguides(5). Strong Brillouin interactions have only recently been realized in a new class of optomechanical structures that control the interaction between guided photons and phonons(5-7). Despite these major advances, appreciable Brillouin-based optical amplification has yet to be observed in silicon. Using a membrane-suspended waveguide, we report large Brillouin amplification in silicon for the first time, reaching levels greater than 5 dB for modest pump powers, and demonstrate a record low(5 mW) threshold for net amplification. This work represents an important step towards the realization of high-performance Brillouin lasers and amplifiers in silicon.</P>

Tunable optical time delay of quantum signals using a prism pair

Gehring, George M.,Shin, Heedeuk,Boyd, Robert W.,Kim, Chil-Min,Ham, Byoung S. The Optical Society 2010 Optics express Vol.18 No.18

<P>We describe a compact, tunable, optical time-delay module that functions by means of total internal reflection within two glass prisms. The delay is controlled by small mechanical motions of the prisms. The device is inherently extremely broad band, unlike time delay modules based on 'slow light' methods. In the prototype device that we fabricated, we obtain time delays as large as 1.45 ns in a device of linear dimensions of the order of 3.6 cm. We have delayed pulses with a full width at half-maximum pulse duration of 25 fs, implying a delay bandwidth product (measured in delay time divided by the FWHM pulse width) of 5.8x10(4). We also show that the dispersion properties of this device are sufficiently small that quantum features of a light pulse are preserved upon delay.</P>

Per- and polyfluoroalkyl substances in frequently consumed foodstuffs in South Korea

Na-Youn Park,HeeDeuk Yang,Sunah Bang,Younglim Kho,Myung-Sub Chung,Kwang-Won Lee,Young-Suk Kim,Jung Hoan Kim 한국식품과학회 2023 한국식품과학회지 Vol.55 No.6

Dietary intake is an important route of exposure to per- and polyfluoroalkyl substances (PFASs). Dietary exposure to PFASs can be caused by contamination of raw food materials or migration of PFASs from food packaging materials. In this study, 133 samples of raw materials and processed food products were purchased to monitor PFASs levels. The samples were selected based on the top 36 types of high-intake and high-frequency foods. The median value of PFASs was the highest in fishery products (2.961 ng/g), and perfluoro-octane sulfonic acid and perfluoro-n-octanoic acid levels in the entrails of fishery products were higher than those found in fish muscle, which is consistent with findings from previous studies. Removing fish entrails from the consumption of fishery products can reduce the risk of exposure to PFASs because PFASs levels are higher in fish entrails than in fish muscle or other food groups.

Extended phase-matching properties of periodically poled potassium niobate crystals for mid-infrared polarization-entangled photon-pair generation

Lee, Kwang Jo,Lee, Sunmi,Shin, Heedeuk The Optical Society 2016 Applied optics Vol.55 No.34

<P>We report the extended phase-matching (EPM) properties of two kinds of periodically poled potassium niobate (KNbO3 or KN) crystals (i.e., periodic 180 degrees- and 90 degrees-domain structures) that are highly useful for the generation of polarization-entangled photon pairs in the mid-infrared (IR) spectral region. Under the degenerate Type II spontaneous parametric downconversion process satisfying the EPM condition, an input single photon with a frequency of 2 omega generates a pair of synchronized photons with identical frequencies of omega that are orthogonally polarized with respect to each other (i.e., the frequency-coincident, polarization-entangled biphoton states). Our simulation results illustrate that the EPM is achievable in the mid-IR spectral region: at the wavelengths of 3.80 mu m and 4.03 mu m for periodic 90 degrees -and 180 degrees-domain structures, respectively. We will describe in detail the EPM properties of both cases in terms of interaction types and the corresponding nonlinear optic coefficients, phase-matching bandwidths, and domain poling periods. The calculated EPM bandwidths are much broader than 200 nm in the mid-IR for both cases, exhibiting a great potential for nonlinear-optic signal processing in quantum communication systems operating in the mid-IR bands. (C) 2016 Optical Society of America</P>

Photon-pair source working in a silicon-based detector wavelength range using tapered micro/nanofibers

Kim, Jin-Hun,Ihn, Yong Sup,Kim, Yoon-Ho,Shin, Heedeuk The Optical Society 2019 Optics letters Vol.44 No.2

LC-MS/MS를 이용한 동물 사료 내 글라이포세이트 및 글루포시네이트 분석

이지수,김완서,양희득,박나연,정웅,김정환,고영림,Lee, Ji-Su,Kim, Wanseo,Yang, Heedeuk,Park, Na-Youn,Jung, Woong,Kim, Junghoan,Kho, Younglim 대한화학회 2019 대한화학회지 Vol.63 No.5

식품에서 글라이포세이트와 글루포시네이트의 함량 기준은 구체적이며 분류가 잘 되어있다. 그러나 동물 사료나 먹이에서의 함량 기준은 비교적 구체적이지 못하며 분류가 미흡한 편이다. 또한 인간에게 미치는 위험에 대해서는 지속적인 논의는 이루어지고 있는 반면에, 동물에게 미치는 위험성은 충분한 연구가 이루어지지 않았다. 본 연구에서는 동물이 글라이포세이트를 섭취하는 경로로 추정되는 사료에서의 분석법을 확립하였다. 25% 메탄올을 이용한 용매추출, 원심분리 후 고체상추출로 정제한 후, 농축하여 LC-MS/MS를 이용하여 정량 분석하였다. 분석법 검증은 검출한계, 정확도 및 정밀도 시험을 통해 진행하였다. 확립된 시험법의 검출한계는 글루포시네이트 $1.8{\mu}g/kg$, 글라이포세이트 $2.4{\mu}g/kg$ 이었다. 정확도는 94.4~103.4%, 정밀도는 1.5~7.2%의 범위로 나타났다. 동물 사료(n=13)를 분석법을 적용시켜 분석한 결과 글루포시네이트는 한 개의 시료에서 검출되었고($ND{\sim}8.8{\mu}g/kg$), 글라이포세이트는 한 개의 시료를 제외한 모든 시료에서 검출($ND{\sim}337.0{\mu}g/kg$)되었다. The standards for the contents of glyphosate and glufosinate in foods are specific and well categorized. However, the standard of content in animal feeds is relatively inadequate and the classification is insufficient. There is also constant debate about the risk of glyphosate and glufosinate to human health, but the risk to animals has not been well studied. In this study, we established an analytical method in feeds that is estimated to be the path for animals to ingest glyphosate. The solvent extraction was carried out using 25% methanol. After centrifugation, samples were purified using solid phase extraction (SPE) and quantitatively analysed using LC-MS/MS after concentrated. Assessment of validation was conducted through detection limits, accuracy, and precision tests. The detection limits for the established method were 1.8 of ${\mu}g/kg$ of glufosinate and $2.4{\mu}g/kg$ of glyphosate. Accuracy was ranged from 94.4% to 103.4% and precision was range from 1.5% to 7.2%. Glufosinate was detected in one sample ($ND{\sim}8.8{\mu}g/kg$) and glyphosate was detected in all but one sample ($ND{\sim}337.0{\mu}g/kg$) by applying the analytical method to animal feeds (n=13).

Fabrication method for ultra-long optical micro/nano-fibers

Lee, Donghwa,Lee, Kwang Jo,Kim, Jin-Hun,Park, Kyungdeuk,Lee, Dongjin,Kim, Yoon-Ho,Shin, Heedeuk Elsevier 2019 CURRENT APPLIED PHYSICS Vol.19 No.12

<P><B>Abstract</B></P> <P>Nonlinear optical interactions can be enhanced dramatically by tight light-confinement and long interaction-length. Optical fiber tapers with micro/nano-thickness waists considerably increase light-matter interactions in or near their waists. Here, we propose and demonstrate a novel tapering method of fabricating uniform, low-loss, and ultra-long micro/nano fibers. The technique comprises three steps for conventional flame-brushing and pulling, recalibration, and one-directional pulling. Using the proposed method, two strands of tapered fibers are fabricated, having 0.82-μm/1.6-μm diameters, 220-mm/500-mm uniform lengths with <55-nm/66-nm diameter variances, and high transmittances of 90.2%/91.5%. A figure of merit indicating the nonlinear-optic efficiency is defined and used to compare the results obtained in this study with those for tapered fibers in references. The proposed tapering method will be very useful for the fabrication of tapered fiber devices exploiting nonlinear optic effects, including Brillouin scattering, Raman amplification, and other third-order nonlinearities for supercontinuum generation.</P>