광통신 III-V/Si 레이저 다이오드 기술 동향

김호성,김덕준,김동철,고영호,김갑중,안신모,한원석,Kim, H.S.,Kim, D.J.,Kim, D.C.,Ko, Y.H.,Kim, K.J.,An, S.M.,Han, W.S. 한국전자통신연구원 2021 전자통신동향분석 Vol.36 No.3

Two main technologies of III-V/Si laser diode for optical communication, direct epitaxial growth, and wafer bonding were studied. Until now, the wafer bonding has been vigorously studied and seems promising for the ideal III-V/Si laser. However, the wafer bonding process is still complicated and has a limit of mass production. The development of a concise and innovative integration method for silicon photonics is urgent. In the future, the demand for high-speed data processing and energy saving, as well as ultra-high density integration, will increase. Therefore, the study for the hetero-junction, which is that the III-V compound semiconductor is directly grown on Si semiconductor can overcome the current limitations and may be the goal for the ideal III-V/Si laser diode.

복잡한 2차원 물체 인식용 로봇 시각장치의 구현에 관한 연구

김호성,김영석,변증남,Kim, Ho-Seong,Kim, Yeong-Seok,Byeon, Jeung-Nam 대한전자공학회 1985 전자공학회지 Vol.22 No.1

A computer vision system for robot is developed which can recognize a variety of two dimensional complex objects in gray level noisy scenes. the system is also capable of determining the position and orientation of the objects for robotlc manipulation. The hardware of the vision system is developed and a new edge tracking technique is also proposed. The linked edges are approximated to sample line drawing by split and merge algorithm. The system extracts many features from line drawing and constructs relational structure by the concave and convex hull of objects. In matching process, the input obhects are compared with the objects database which is formed by learning ability. Thelearning process is so simple that the system is very flexible. Several examples arc shown to demonstrate the usefulness of this system.

연료전지의 수소저장용 마그네슘계 합금의 표면제어에 의한 전기화학적 수소화 거동 연구

김호성,이종호,부성재,Kim, Ho-Sung,Lee, Jong-Ho,Boo, Seong-Jae 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.7

The effects of surface treatment on the hydrogen storage properties of a $Mg_2Ni$ alloy particle were investigated by the microvoltammetric technique, in which a carbon-filament microelectrode was manipulated to make electrical contact with the particle in a KOH aqueous solution. It was found that the hydrogen storage properties of $Mg_2Ni$ at room temperature were improved by the surface treatment with a nickel plating solution. The sodium salts(sodium phosphate and sodium dihydrogen citrate) contained in the nickel plating solution made the alloy form an amorphous-like state, resulting in an improved hydrogen charge/discharge capacity at room temperature as high as about 150[mAh/g] from the original value of 17[mAh/g]. Potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-8}{\sim}10^{-9}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. [ $Mg_2Ni$ ]계 합금 입자의 수소저장 특성에 대한 표면처리 효과가 마이크로 전극 측정법에 의해 검토되었다. 카본-섬유로 된 마이크로 전극을 KOH 수용액 속에서 조정자를 사용하여 수소 단일입자에 접촉시켰다. 상온에서 $Mg_2Ni$ 합금의 수소저장 특성은 니켈 도금용액에 의한 표면 처리에 의해 크게 개선되었다. 니켈 도금용액 속에 있는 함유된 나트륨염(sodium phosphate 및 sodium dihydrogen citrate)이 합금을 아몰퍼스와 같은 형태로 만들었으며, 그 결과 상온에서 수소 흡장/방출 용량이 최초의 17[mAh/g]에서 150[mAh/g]로 향상되었다. 합금 입자 내에서 수소원자의 겉보기 화학적 확산계수를 계산하기 위하여 Potential-step 실험을 실시하였으며 데이터 해석을 위해 구형확산 모델을 적용하였다. 실험결과로서 겉보기 확산계수($D_{app}$)는 수소 흡장 및 방출되는 전 과정에서 $10^{-8}{\sim}10^{-9}[cm^2/s]$ 수준인 것으로 확인되었다.

지대주 각도와 연결방식이 지르코니아 지대주의 파절강도에 미치는 영향

김호성,조혜원,Kim, Ho-Seong,Cho, Hye-Won 대한치과보철학회 2017 대한치과보철학회지 Vol.55 No.1

목적: 내부 연결형과 외부 연결형의 임플란트에서 직선형과 경사형 지르코니아 지대주의 파절강도를 비교하였다. 재료 및 방법: 내부육각 연결형 임플란트 20개와 외부육각 연결형 임플란트 20개에, 기성 직선형 지르코니아 지대주와, $17^{\circ}$ 경사형 지르코니아 지대주를 10개씩 체결하였다. 시편은 연결 방식과 지대주 각도에 따라 4개의 군으로 나누었다: 내부 연결형/ 직선형 지대주, INS군; 내부 연결형/ 경사형 지대주, INA 군; 외부 연결형/ 직선형 지대주, EXS 군; 외부 연결형/ 경사형 지대주, EXA 군. 모든 시편은 만능시험기에서 1 mm/min의 crosshead speed로 $30^{\circ}$ 하중을 가했다. 지대주의 파절강도를 측정하고, 2-way ANOVA와 independent t-test로 통계처리 하였다(${\alpha}=.05$). 결과: 각 군의 평균파절강도는 다음과 같다: INS군, 955.91 N; INA군, 933.65 N; EXS군, 1267.20 N; EXA군, 1405.93 N. 외부 연결형이 내부 연결형에 비해 파절강도가 높았다(P < .001). 내부연결형(P = .747)과 외부 연결형(P = .222)에서 지대주 각도에 따른 파절강도는 차이가 없었다. 또한 내부 연결형 지대주는 육각 부위에서 수평 파절이 일어난 반면, 외부 연결형 지대주는 설측 치경부에서 파절되었다. 결론: 외부 연결형 지르코니아 지대주가 내부 연결형 지대주에 비해 파절 강도가 높았고, 직선형과 경사형 지르코니아 지대주의 파절강도는 차이가 없었다. Purpose: The purpose of this study was to evaluate the fracture strength of straight and angled zirconia abutments for internal hex and external hex implants. Materials and methods: Twenty internal hex implants and 20 external hex implants were prepared. The prefabricated straight zirconia abutments and 17-degree-angled zirconia abutments were connected to those 40 implants. The specimens were classified into 4 groups depending on the connection type and abutment angulation; internal hex implant/straight abutment, group INS; internal hex implant/angled abutment, group INA; external hex implant/straight abutment, group EXS; external hex implant/angled abutment, group EXA. All specimens were loaded at a 30-degree angle with a crosshead speed of 1 mm/min using universal testing machine. The fracture loads were analyzed using 2-way ANOVA and independent t-test (${\alpha}=.05$). Results: The mean fracture load for INS was 955.91 N, 933.65 N for INA, 1267.20 N for EXS, and 1405.93 N for EXA. External hex implant showed a significantly higher fracture load, as compared to internal hex implant (P < .001). No significant differences in fracture loads were observed between the straight and angled abutment in internal hex implants (P = .747) and external hex implants (P = .222). Internal hexes of abutments were fractured horizontally in internal connection implants, while lingual cervical neck portions were fractured in external connection implants. Conclusion: The zirconia abutments with external hex implants showed significantly higher fracture strength than those with internal hex implants. However there was no difference in fracture strength between the straight and 17-degree-angled zirconia abutment connected to both implant systems.

카뮈의 『이방인』에 대한 불교적 이해

김호성(Kim, Ho Sung) 한국동서비교문학학회 2012 동서 비교문학저널 Vol.0 No.27

The Stranger (L’Etranger, 1942), written by Albert Camus (1913-1960), is hard to fully comprehend, because it is true that normal people have difficulty relating to and understanding the life of Meursault, the protagonist. Although his mother dies, Meursault does not grieve or cry. The very next day following his mother’s funeral, moreover, he goes to swim and sleep with a woman. How can we understand his behavior? Is he merely a depraved person?<br/> I propose a new way of seeing the Stranger?from the Buddhist perspective?and so I turn to Seri Kim’s suggestion of relating the thought of Camus to that of Eastern philosophy.<br/> There are two possible methods for understanding The Stranger as it relates to Buddhism. On one hand, the absurdity that Meursault reveals can be compared to impermanence in Buddhism, because the natural principle revealed in The Stranger is an archetype of the impermanence doctrine that “whoever is born is destined to die.” In addition, Meursault rejects the substance-self as the metaphysical Supreme One. I would argue that ‘rebirth’ (samsara, 輪廻) is doctrine of impermanence, or natural principle, to the predictable objection that samsara in Buddhism opens the possibility of hopeful wishing. In contrast to the phrase, “escaping suffering from the actual world makes it possible to go to the heaven,” Buddhist tradition?at least early Buddhism, Prajna (般若) Buddhism, and Chan (禪) Buddhism?emphasizes “overcome suffering here and now not to repeatedly experience suffering of rebirth.” I would call it ‘Self-endeavored Buddhism for enlightenment.’<br/> On the other hand, I would point out the ethical behavior of disobedience which is illustrated in the final meeting between Meursault and the priest is a kind of religious or mystical experience. Meursault’s experience is quite similar to the idea that “the form is the emptiness,” i.e. r pa (色) is nyat (空), which becomes complete in the eighth picture (人牛忘) of Drawings of the Ten Bulls (十牛) in Chan Buddhism. Hence, the later change of Meursault is the way to the ninth picture (返本還源) and the tenth picture (入?垂手)?that is, he returns from emptiness to form. Ultimately, while the discord between the absurd and order is the negative aspect of emptiness, Meursault’s state after ‘suddenly bursting’ is the positive aspect of emptiness. Hence, The Stranger is a kind of text that can illustrate the dual aspects of emptiness, or the Middle Way (中道). At this point, Camus creates a new ‘Buddha’ or a ‘Chan master’ in his own way, although Meursault is unable to come back to the secular world, just as is the analogous case of the marketplace in the tenth picture of Drawings of the Ten Bulls.

마이크로전극에 의한 니켈수소전지용 수산화니켈 입자의 전기화학적 거동

김호성,오익현,이종호,Kim, Ho-Sung,Oh, Ik-Hyun,Lee, Jong-Ho 한국전기화학회 2007 한국전기화학회지 Vol.10 No.2

본 논문은 마이크로전극 측정시스템을 사용하여 니켈수소전지의 전극 소재로 사용되고 있는 수산화니켈의 단일 입자에 대해 전기화학적 평가를 수행 하였다. 즉 Carbon fiber 마이크로전극을 수산화니켈 입자 한개 위에 전기적인 접촉을 이루도록 조정하고 전기화학적 평가를 수행하였다. Cyclic Voltammetry 실험 결과 수산화니켈의 산화 환원 반응과 산소 발생 반응(OER)이 명확하게 분리 되고 있음을 확인하였으며, 전위주사속도를 증가 시킬 경우 환원 전하량은 주사 속도에 의존하지 않고 거의 일정한 수치를 보여 주고 있으나, 산화 전하량은 환원 전하량 보다 크고 주사속도 구간에서 부반응인 산소발생이 증가하고 있음을 확인했다. 그리고 Calvanostat에 의한 정전류 충방전 실험의 결과 수산화니켈 단일 입자의 방전용량은 이론용량 289 mAh/g에 근접한 수치(약 250 mAh/g)를 보여 주었으며 또한 Potential Step에 의해 단일 입자내의 수소이온 확산계수($D_{app}=3{\sim}4{\times}10^{-9}\;cm^2/s$)가 얻어졌다. Electrochemical studies were performed for a single particle of nickel hydroxide for the cathode of Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and electrochemical experiments were performed. As a result of cyclic voltammetry, the oxidation/reduction and oxygen evolution reaction (OER) are clearly separated for a single particle. The total cathodic charge (Qred) is practically constant for the scan rate investigated, indicating that the whole particle has reacted. The total anodic charge(Qox) was larger than that of reduction reaction, and the magnitude of oxygen evolution taking place as a side reaction was enhanced at lower scan rates. As a result of galvanostatic charge and discharge measurement, the discharge capacity of single particle was found to be 250 mAh/g, value being very close to the theoretical capacity (289 mAh/g). The apparent proton diffusion coefficient(Dapp) using potential step method inside the nickel hydroxide was found to range within $3{\sim}4{\times}10^{-9}\;cm^2/s$.

한국어 청자의 한국어 폐쇄음 청취오류: 기식성을 중심으로

김호성,Kim Hoseong 대한음성학회 2003 말소리 Vol.45 No.-

This is a study on perception errors of Korean stops in word initial position. This study will show how listeners perceive manipulated Korean stops through two experiments and I will analyze why they are confused. In addition, 1 will show those perception errors not only reflect the relationship between the place and manner of articulation but also ate deeply related to the length of aspiration.

Fabrication and remote laser ignition of Al/CuO energetic nanocomposites incorporated with functional dyes for enhanced light absorption

김호성,Jeong Keun Cha,Ji Hoon Kim,김수형 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.82 No.-

In this study, we investigated the effects of dyes on the laser ignition characteristics of Al nanoparticles(NPs) and CuO NPs-based energetic nanocomposites. Various functional dyes (e.g., N-719, rose bengal(RB), methylene blue (MB)) were employed as a light absorbing medium for Al/CuO energeticnanocomposites. According to UV–vis spectrometer analysis results, N-719, RB, and MB dyes hadrelatively strong light absorption in the blue, green, and red wavelength ranges, respectively. The resultsof red, green, and blue (RGB) laser ignition tests for various dye-coated Al/CuO composites demonstratedthat the laser ignition threshold power density for the composites gradually decreased with increasingdye concentration. To test the possibility of selective optical ignition, the various dye-coated Al/CuOcomposites were irradiated using RGB laser beams operating with afixed and relatively low powerdensity. The results showed that the N-719-, RB-, and MB-coated Al/CuO composites were onlysuccessfully ignited under the condition of blue, green, and red laser beam irradiation, respectively. Thissuggests that energetic nanocomposites coated with special dyes could be employed as potential ignitersand heat energy sources, the reactions of which are initiated by selective and remote light-energyirradiation, in various thermal engineering applications.

HEV 및 PEMFC 연료전지용 니켈수소 전지의 전극재료에 대한 전기화학적 평가

김호성,Kim, Ho-Sung 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.2

본 논문은 마이크로 전극 측정 시스템을 사용하여 차세대 신동력 산업인 HEV(Hybrid Electric Vehicle) 및 수소연료전지(PEMFC) 차량용 니켈 수소전지의 전극소재로 사용되고 있는 수소저장합금(Mm : misch metal, $MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$)의 단일 입자에 대해 전기화학적 수소 흡방출 특성 평가를 수행 하였다. 즉 Carbon fiber 마이크로 전극을 합금 입자 한개 위에 전기적인 접촉을 이루도록 조정하고, Cyclic Voltammetry 및 Galvanostatic 충방전 실험을 수행하였다. 그 결과 단일 입자의 방전용량은 약 280[mAh/g]로 이론용량의 약 90[%]의 특성을 보여 주었다. 데이터는. 실제 Ni-MH전지를 구성하는 합금입자 그리고 폴리머 바인더로 구성된 Composite film 전극과 비교 하였다. 추가적으로 합금의 단일 입자에 있어 in situ 미분화 현상을 관찰하였다. 마이크로 전극 측정 시스템에 의한 단일 입자의 전기화학적 평가는 기존의 Composite Film 전극에 비해 수소저장합금에 대해 보다 상세하고 정확한 정보를 쉽게 얻을 수 있었다. Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : misch metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for the anode of Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the cyclic voltammetry and the galvanostatic charge/discharge experiments were performed. A single particle of the alloy showed the discharge capacity of 280[mAh/g], the value being 90[%] of the theoretical capacity. Data were compared with that of the composite film consisting of the alloy particles and a polymer binder, which is more practical form for Ni-MH batteries. Additionally, pulverization of the alloy particles are directly observed. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

연료전지의 수소저장용 합금에 대한 수소확산반응의 속도론적 해석

김호성,Kim, Ho-Sung 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.2

본 논문은 마이크로 전극 시스템에 의하여 연료전지 및 Ni-MH 전지로의 응용을 가정한 $AB_5$계 수소저장합금인 $MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$의 단일 입자에 대하여 전기화학적인 평가를 수행하였다. 즉 Carbon fiber 마이크로 전극을 합금 입자 한개 위에 전기적인 접촉을 이루도록 조정하고, 합금 입자 내에서 수소원자의 겉보기 화학적 확산계수를 계산하기 위하여 Potential-Step 실험을 실시하였다. 여기에서 사용되는 합금입자는 치밀하고 전도성이 있는 구형이므로 데이터 해석을 위해 구형확산 모델을 적용하였다. 실험결과로서 겉보기 확산계수($D_{app}$)는 수소 흡장 및 방출되는 전 과정에서 $10^{-9}$과 $10^{-10}[cm^2/s]$ 수준인 것으로 확인되었다. 마이크로 전극 측정 시스템에 의한 단일 입자의 전기화학적 평가는 기존의 Composite Film 전극에 비해 수소저장합금에 대해 보다 상세하고 정확한 정보를 쉽게 얻을 수 있었다. Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : minh metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for fuel cell and Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-9}\;and\;10^{-10}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.