• 로봇학회논문지
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• 제16권1호
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• pp.64-71
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• 2021

This paper describes a robotic teleoperation system to perform an accurate needle insertion into a cornea for a separation between the stromal layer and Descemet's membrane during deep anterior lamellar Keratoplasty (DALK). The system can reduce the hand tremor of a surgeon by scaling the input motion, which is the control input of the slave robot. Moreover, we utilize corneal applanation to estimate the insertion depth. The proposed system was validated by performing the layer separation using 25 porcine eyes. The average depth of needle insertion was 742 ± 39.8 ㎛ while the target insertion depth was 750 ㎛. Tremor error was reduced from 402 ± 248 ㎛ in the master device to 28.5 ± 21.0 ㎛ in the slave robot. The rate of complete success, partial success, and failure were 60, 28, and 12%, respectively. The experimental results showed that the proposed system was able to reduce the hand tremor of surgeons and perform precise needle insertion during DALK.

• 한국표면공학회지
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• 제49권3호
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• pp.252-259
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• 2016

In order to form an aluminum-doped zinc oxide (AZO) transparent electrode film on a polyethylene terephthalate (PET) substrate used for a flexible display substrate, the AZO transparent electrode was produced at low temperature without substrate heating. Even though the produced electrode showed characteristic optical transmittance of 90 % (at 550 nm) and sheet resistance within $100{\Omega}/sq$, cracks occurred 10 minutes after loading applied 2 mm radius of curvature, and the sheet resistance increased linearly. An insertion layer of ZrCu was formed between the AZO film and the PET substrate to suppress the generation of cracks on the AZO film. It was verified that the crack was not generated 30 minutes after the loading of 2 mm radius of curvature, and no increase in sheet resistance was recorded. There was also not cracks in the dynamic bending test of 4 mm radius, but surface resistance was slightly increased. As a result, the ZrCu insertion film improved the interfacial adhesion between the substrate and AZO film layer without increasing sheet resistance and decreasing transmittance.

• 한국자기학회지
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• 제16권3호
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• pp.173-177
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• 2006

수직자기이방성을 갖는 [Pd/Co] 다층박막으로 구성된 스핀밸브 구조에서 비자성층(space layer, SL) Pd 또는 Cu의 두께와 다층박막의 반복층수 N에 따른 자기저항효과의 의존성을 연구하였다. 비자성층을 Pd보다 Cu로 사용하였을 때 더 큰 자기저항비를 얻었다. 그리고 Cu층과 고정층 사이에 Co층을 삽입하는 경우 약 3배가량 자기저항비가 증가하는 것을 관찰하였다. $Ta_{(2.1nm)}/[Pd_{(0.61)}/Co_{(0.23)}]_4/Cu_{(2.37)}/Co_{(t)}/[Pd_{(0.61)}/Co_{(0.23)}]_2/FeMn_{(10.6)}/Ta_{(2.1)}$ 구조에서 삽입된 Co층의 두께가 0.62nm 또는 1.01nm에서 최대의 자기저항비 7.4%를 얻었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.346.1-346.1
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• 2014

Porous nano crystalline $TiO_2$ is currently used as a working electrode in a dye-sensitized solar cell (DSSC). The conventional working electrode is comprised of absorption layer (particle size:~20 nm) and scattering layer (particle size:~300 nm). We inserted window layer with 10 nm particle size in order to increase transmittance and specific surface area of $TiO_2$. The electrochemical impedance spectroscope analysis was conducted to analysis characterization of the electronic behavior. The Bode phase plot and Nyquist plot were interpreted to confirm the internal resistance caused by the insertion of window layer and carrier lifetime. The photocurrent that occurred in working electrode, which is caused by rise in specific surface area, increased. Accordingly, it was found that insertion of window layer in the working electrode lead to not only effectively transmitting the light, but also increasing of specific surface area. Therefore, it was concluded that insertion of window layer contributes to high conversion efficiency of DSSCs.

• 한국자기학회지
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• 제8권2호
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• pp.79-85
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• 1998

e-beam evaporator로 [Ni80Fe20/Cu/Co/Cu] 다층박막을 증착하여 자성층 사이의 교환 결합 상태에 따라 Co를 Ni80Fe20/Cu 계면에 삽입, 자기 저항비와 자기 저항비와 자화 곡선의 변화를 연구하였다. 강자성 결합 및 비 결합에서는, 계면에 Co를 삽입하게 되면, 자기 저한 값이 증가하지만 반강자성 결합에서는 자기 저항 값이 감소하는 경향이 보였다. 이러한 원인은 계면에 삽입되는 Co가 계면 산란을 증가시키는 것 뿐만 아니라 자성층 간의 교환 결합상태를 변화 시키기 때문에 것으로 판단된다. 아울러 계면에 삽입된 Co는 박막의 다층 구조를 30$0^{\circ}C$ 이상까지 유지시키며 이는 Cork 효과적인 확산 장애물(diffusion barrier)역할을 하기 때문으로 판단된다.

• 한국음향학회지
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• 제39권4호
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• pp.227-236
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• 2020

해양구조물의 파일링 소음을 줄이기 위한 기포커튼과 선체 진동에 의한 수중방사소음 차단을 위한 에어마스커에 대하여 각각의 삽입손실 해석해를 유도하였다. 해석해를 구하기 위해 기포커튼과 에어마스커를 각각 '유체-기포층-유체' 그리고 '진공-평판-유체-기포층-유체'의 단순 모델로 가정하였고, 각 모델에서 해당 기포층을 복소수 형태의 파수와 임피던스로 규정된 유효매질로 치환하였다. 수치 모의를 통해 기포의 분포, 기포율, 그리고 기포층의 두께에 따른 삽입손실의 특성을 살펴보았다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.426.1-426.1
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• 2016

We report high work function Aluminum doped zinc oxide (AZO) films as insertion layer as a function of O2 flow rate between transparent conducting oxides (TCO) and hydrogenated amorphous silicon oxide (a-SiOx:H) layer to improve open circuit voltage (Voc) and fill factor (FF) for high efficiency thin film solar cell. However, amorphous silicon (a-Si:H) solar cells exhibit poor fill factors due to a Schottky barrier like impedance at the interface between a-SiOx:H windows and TCO. The impedance is caused by an increasing mismatch between the work function of TCO and that of p-type a-SiOx:H. In this study, we report on the silicon thin film solar cell by using as insertion layer of O2 reactive AZO films between TCO and p-type a-SiOx:H. Significant efficiency enhancement was demonstrated by using high work-function layers (4.95 eV at O2=2 sccm) for engineering the work function at the key interfaces to raise FF as well as Voc. Therefore, we can be obtained the conversion efficiency of 7 % at 13mA/cm2 of the current density (Jsc) and 63.35 % of FF.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.148-149
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• 2012

This paper reports doping of carbon atoms in GaN layer, which based on dimethylhydrazine (DMHy) and growth temperature. It is well known that dislocations can act as non-radiative recombination center in light emitting diode (LED). Recently, many researchers have tried to reduce the dislocation density by using various techniques such as lateral epitaxial overgrowth (LEO) [1] and patterned sapphire substrate (PSS) [2], and etc. However, LEO and PSS techniques require additional complicated steps to make masks or patterns on the substrate. Some reports also showed insertion of carbon doped layer may have good effect on crystal quality of GaN layer [3]. Here we report the growth of GaN epitaxial layer by inserting carbon doped GaN layer into GaN epitaxial layer. GaN:C layer growth was performed in metal-organic chemical vapor deposition (MOCVD) reactor, and DMHy was used as a carbon doping source. We elucidated the role of DMHy in various GaN:C growth temperature. When growth temperature of GaN decreases, the concentration of carbon increases. Hence, we also checked the carbon concentration with DMHy depending on growth temperature. Carbon concentration of conventional GaN is $1.15{\times}1016$. Carbon concentration can be achieved up to $4.68{\times}1,018$. GaN epilayer quality measured by XRD rocking curve get better with GaN:C layer insertion. FWHM of (002) was decreased from 245 arcsec to 234 arcsec and FWHM of (102) decreased from 338 arcsec to 302 arcsec. By comparing the quality of GaN:C layer inserted GaN with conventional GaN, we confirmed that GaN:C interlayer can block dislocations.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권5호
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• pp.423-433
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• 2016

In this paper, we consider the cybersecurity issue of ship information system (SIS) from a new perspective which is called opacity. For a SIS, its confidential information (named as "secret") may be leaked through the working behaviors of each Distributed Control Unit (DCU) from an outside observer called an "intruder" which is able to determine ship's mission state by detecting the source of each data flow from the corresponding DCUs in SIS. Therefore we proposed a dual layer mechanism to enforce opacity by activating non-essential DCU during secret mission. This mechanism is calculated by two types of insertion functions: Safety-assured insertion function ($f_{IS}$) and Admissibility-assured insertion function ($f_{IA}$). Due to different objectives, $f_{IS}$ is designed to confuse intruder by constructing a non-secret behaviors from a unsafe one, and the division of $f_{IA}$ is to polish the modified output behaviors back to normal. We define the property of "$I_2$-Enforceability" that dual layer insertion functions has the ability to enforce opacity. By a given mission map of SIS and the marked secret missions, we propose an algorithm to select $f_{IS}$ and compute its matchable $f_{IA}$ and then the DCUs which should be activated to release non-essential data flow in each step is calculable.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 학술대회 및 기술세미나 논문집 디스플레이 광소자
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• pp.83-84
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• 2006

ITO/4, 4', 4"-tris (N -3 - methylphenyl - N - phenyl - amino) - triphenylamine, [m-MTDATA] / Terbium Iris - (1 - phenyl - 3 - methyl - 4 - (tertiarybutyryl) - pyrazol - 5 - one) triphenylphosphine oxide [$(tb-PMP)_3Tb-(Ph_3PO)$] / Mg:Ag devices were made to investigate its electrical and light emission properties. The thickness of m-MTOATA layer was varied from 0 to 80 nm. There was a threshold thickness for the sufficient hole injection. The insertion of 20 nm thick m-MTDATA layer between ITO and Tb-complex resulted in the right shift of current-voltage curve because of the insufficient hole injection. The low operating voltage can be obtained above the 40 nm of m-MTDATA layer. The insertion of m-MTDATA induced the increase of the background in the electroluminescence spectrum which was dependent on the current density of the devices.