알루미늄 PEO 코팅의 결정상에 미치는 공정 조건에 대한 연구 I. Unipolar 펄스와 코팅시간

김배연,함재호,이득용,김용남,전민석,김기윤,최지원,김성엽,김광엽,Kim, Bae-Yeon,Ham, Jae-Ho,Lee, Deuk Yong,Kim, Yong-Nam,Jeon, Min-Seok,Kim, Kiyoon,Choi, Ji-Won,Kim, Sung Youp,Kim, Kwang Youp 한국결정성장학회 2014 韓國結晶成長學會誌 Vol.24 No.2

전해질로 $Na_2SiO_3$을 사용하여 A1050 알루미늄 판재를 pulse 폭 $ 2000{\mu}sec$, impulse 420 V, 400 ${\mu}$sec의 unipolar pulse로 플라즈마 전해 산화 코팅(plasma electrolytic oxidation coating)을 하여 산화 피막을 2, 5, 15, 30분에 따라 형성시킨 다음 산화피막을 분석하였다. 표면에 형성된 산화물의 결정상은 ${\alpha}-alumina$와 ${\gamma}-Alumina$로서 시간에 따른 변화는 없었다. 반응 초반에는 ${\gamma}-Alumina$가 많이 생성되었지만 시간이 갈수록 ${\gamma}-Alumina$의 양에는 변화 없이 ${\alpha}-alumina$가 많이 생겨남을 알 수 있었다. 이런 결과는 micro plasma에 의해서 ${\gamma}-Alumina$가 우선 생성되고, 이후 계속되는 micro plasma의 열에 의해서 ${\alpha}-alumina$로의 전이가 일어나기 때문으로 판단된다. Crystallographic phases of Plasma electrolytic oxidized Al alloy, A1050, were investigated. The electrolyte of PEO was $Na_2Si_2O_3$ and KOH. Unipolar pulse, $ 2000{\mu}sec$ with $400{\mu}sec+420V$ impulse, were applied for 2 min, 5 min, 15 min, and 30 min. ${\gamma}-Alumina$, as well as ${\alpha}-alumina$, was main crystal phase. ${\gamma}-Alumina$ was appeared in the beginning, then the amount of ${\alpha}-alumina$ was increased with time, but the amount of ${\gamma}-Alumina$ remained constant without any increasing. So, it is concluded that plasma gas produce ${\gamma}-Alumina$ at the first, and then ${\gamma}-Alumina$ transform ${\alpha}-alumina$ finally. During the transformation, high temperature of micro plasma gives transformation energy.

經皮電氣刺戟을 위한 强度,周波數,듀티비 效果에 관한 硏究

함광근,허 웅,이호재,민홍기 明知大學校 産業技術硏究所 1992 産業技術硏究所論文集 Vol.11 No.-

In this paper, we have searched for the optimal electro-stimulation condition which for the electrotactile matrix device. The required parameters of electro-stimulus condition for the experiments are waveforms, frequency stimulation intensity, duty ratio. As a result, when we gave a stimulation to finger's skin with monophasic, biphasic and differential phasic waveform, the most appropriate stimulation condition was 200 to 250[Hz] in frequency, 10 to 25[%] in duty ratio. A Burst type pulse was more sensitive than that of the continuous pulse.

시각장애자용 문자인지 장치에 관한 연구

허웅,조병서,김진곤,함광근,민홍기 明知大學校 産業技術硏究所 1994 産業技術硏究所論文集 Vol.13 No.-

In this paper, we implemented the hangeul tactile recognition system for the Blind. The system is consist of hardware part and software part.The hardware part is consist of a scanner interface image processing system, a electro tactile output device inter and auser interface. The software system consist of pattern learning routine,image processing and character pattern output routine, file management and operation window routine. The 16 by 16 of return electrode is driven by a electro-tacttile device. The recognition experimention distinguished learning beforefrom learning after,after learning the recognition rate is higher than learning before. As a results of experimentation before and after learning,the later is superior to the former. Therefore,if learning is increased, we can take higher recognition rate.

알루미늄 PEO 코팅의 결정상에 미치는 공정 조건에 대한 연구 II. Bipolar 펄스와 전해액

김배연,함재호,이득용,김용남,전민석,김기윤,최지원,김성엽,김광엽,Kim, Bae-Yeon,Ham, Jae-Ho,Lee, Deuk Yong,Kim, Yong-Nam,Jeon, Min-Seok,Kim, Kiyoon,Choi, Ji-Won,Kim, Sung Youp,Kim, Kwang Youp 한국결정성장학회 2014 한국결정성장학회지 Vol.24 No.2

A1100, A5052, A6061, A6063, A7075 규격의 시판 알루미늄 합금 판재를 $Na_2SiO_3$와 $Na_2P_2O_7$ 전해질에서 pulse폭 $2000{\mu}sec$, + impulse 420 V, $400{\mu}sec$, -impulse $300{\mu}sec$의 bipolar pulse로 플라즈마 전해 산화 코팅(plasma electrolytic oxidation coating)한 산화피막의 결정상을 분석하였다. 표면에 형성된 산화물의 결정상은 ${\alpha}-alumina$, ${\gamma}-alumina$, ${\eta}-alumina$, $Al_{4.95}Si_{1.05}O_{9.52}$, 그리고 $(Al_{0.9}Cr_{0.1})_2O_3$가 관찰되었다. Bipolar pulse에 의해서 전해액의 성분인 Si가 산화피막에 포함되며, 포함된 Si는 결정상을 형성하기도 하지만 유리상을 형성시킨다. 이때 합금의 Mg 성분은 유리상의 양을 증가시킨다. Micro plasma에 의해서 용융된 표면은 유리상이 먼저 형성되고 이후 계속된 micro plasma의 열에 의하여 새로운 결정상으로 전이가 일어나는 과정을 거치며, 이에 따라 기존에 보고된 결정상이외에도 다양한 결정상이 형성될 수 있음을 추측할 수 있다. Crystallographic phases of Plasma electrolytic oxidized Al alloy, A1100, A5052, A6061, A6063, A7075, were investigated. Two types of electrolyte $Na_2Si_2O_3$ and Na2P2O7 were also compared. Bipolar pulse, $2000{\mu}sec$ with $400{\mu}sec+420V$ impulse and $300{\mu}sec$ - impulse were applied for 20 min. ${\alpha}-alumina$, ${\gamma}-alumina$, ${\eta}-alumina$, $Al_{4.95}Si_{1.05}O_{9.52}$, and $(Al_{0.9}Cr_{0.1})_2O_3$ were mainly observed. Si, component of electrolyte, were moved into the PEO layer by bipolar pulse. Glassy phase was also observed at the surface of $Na_2Si_2O_3$ electrolyte treated PEO layer, and increased with the Mg content of Al alloy. It is concluded that at first glassy phase was formed by the micro plasma, and the high temperature of plasma turns glassy phase to several crystalline phases. And we could expect that many other crystalline phase could be formed by PEO process.

Application of Continuous Hemofiltration (CHF) to Critically Ill Surgical Patients

Kwang Bo Kwun,Hee Won Ham,Min Chul Shim,Bo Yang Suh,Sung Hoon Kim Korean Society of Critical Care Medicine 1986 Acute and Critical Care Vol.1 No.1

Continuous hemofiltration (CHF) is an extracorporeal process in which fluid electrolytes and other lower molecular weight substances are removed from the patient by ultrafiltration over an extended period. There are several kind of small handy commercially available hemofilters. This device requires only a small amount of blood flow rate (20-70 ml/min) for effective hemofiltration so we applied CHF for various patients who needed dialysis but whose clinical condition precluded either hemodialysis or peritoneal dialysis. 8 patients were treated. 6 were extremely unstable hemodynamically (mean BP around 60mmHg) and 4 were not indicated for peritoneal dialysis because of abdominal pathologies. Angioaccess was by percutaneous needle puncture artery and venous catheterization or Scribner shunt. Average duration of CHF was 55 hours ranging 24-96 hours. Hemofiltration rate were about 3-12 ml/min. Chemical composition of filtrate was same as plasma except very low protein and protein-bound substances. Removal of urea was 5-17 Gms/24hrs. Fluid loss from CHF was replaced by volume to volume. For 4 patients with massive fluid overload volume replacement was restricted to none to I/2 of this filtrates, ln these 4 patients, average about 2,000ml/24hrs of negative fluid balances were achieved without significant hemodynamic alteration. CHF is a simple, safe and effective treatment for acute renal failure and volume overloaded patients who are not indicated for either hemodialysis or peritoneal dialysis due to their conditions.

편액에 함의된 경관 및 상징요소의 출현특성 - 한국의 담양원림과 중국의 소주원림을 중심으로 -

함광민 ( Ham Kwang-min ),이수화 ( Li Shu-hua ),장아평 ( Zhang Ya-ping ),미타니토루 ( Mitani Toru ),장준화 ( Zhang Jun-hua ) 한국전통조경학회(구 한국정원학회) 2016 한국전통조경학회지 Vol.34 No.4

16세기 한국의 담양원림과 중국 소주원림의 편액에 함의된 경관 및 상징요소의 출현특성을 비교분석한 본 연구의 결과는 다음과 같다. 첫째, 편액에 함의된 경관요소 중, 식물요소의 출현율이 양국 원림에서 높게 나타났다. 담양원림의 경우 원림 주변에 조성된 죽림과 자연림이, 소주 원림의 경우 인공적으로 조성한 가산(假山)과 수변 주변의 연, 대나무, 소나무를 포함한 다양한 식물이 편액의 의미에 반영 된 것이 특징이다. 반면, 풍경의 정취를 고조시키는 비, 바람, 달 등을 포함한 기후 및 천체요소는 담양원림의 편액과, 건물과 다리, 책 등을 포함한 인공요소는 소주원림의 편액과 관련되는 것이 특징이다. 이는 산수가 수려한 곳에 찾아 들어가 인공을 최소화하고 자연과의 합일을 미적 이상으로 삼는 한국원림의 특징과, 평탄한 곳에 원림의 경계와 경물을 인공적으로 조성하고 자연과의 동화를 미적 이상으로 삼는 중국원림의 특징을 명확히 하는 근거로 수렴될 수 있겠다. 둘째, 편액에 함의된 상징요소 중, 성인(聖人)의 기본덕목인 도덕적 인품이 두 지방 원림의 사유세계에 있어 보편적 특징으로 나타난다. 반면, 정치안정에 대한 의지는 담양원림의 편액과, 선조를 회고하고 기리는 마음은 소주원림의 편액과 관련되는 것이 특징이다. 이는 사회ㆍ정치적 양상과 연관된 것으로, 당시 호남세력들의 정치적 이상이, 강남 봉건세력들의 유교적 이념이 원림 향유 속에 드러난 것으로 이해된다. 셋째, 담양원림의 편액에 함의된 상징요소 「도덕」과 「정치안정」은 기후와 천체요소가 만들어내는 정경(情景)적 분위기와, 소주원림의 편액에 함의된 상징요소 「도덕」은 식물이 갖는 상징적인 의미와 깊게 관련되어 있고, 이는 한중 원림의 영역을 눈에 보이지 않는 비가시(非可視)영역으로 확장하는 특징과 연결된다. The comparative analysis result of appearance characteristic of landscape elements and symbolic elements implied by the tablets on the 16th century`s Korean Damyang garden and Chinese Suzhou garden is as follows. First, among the landscape elements implied in the tablets, appearance rate of botanical factors appeared high in the gardens of both areas. Damyang garden displayed bamboo grove and natural forest around the garden, while Suzhou garden displayed artificial mountain(假山) created artificially and a variety of plants including lotus, bamboo, and pine surrounding it were associated with the significance of the tablets. On the other hand, climatic/celestial elements including the rain, wind, and the moon were associated with the tablets of Damyang garden, while the artificial factors such as the building, bridge, and book, etc. were mostly were associated with the tablets of Suzhou garden. Second, among the symbolic elements included in the tablets, ethical personality which is the basic virtue of a noble man(聖人), was the universal characteristic of the meditation world of the garden in both areas. However, a will for political stability was mostly associated with the tablets of Damyang garden, while the retrospect heart for the immortal was mostly associated with the signboard in Suzhou garden. It was concerned with political ideal and the thought of Confucianism respectively. Third, the symbolic elements that appeared frequently in the tablets of Damyang garden, 「Ethics」 and 「Political stability」, were associated with the scene atmosphere created by the climatic elements and celestial elements. On the contrary, the symbolic elements which most frequently appeared in the tablets of Suzhou garden, 「Ethics」, was associated with the symbolic significance of the plant. The invisible space of gardens was expanded by tablets in both areas.

Etching Characteristics of VO₂Thin Films Using Inductively Coupled Cl₂/Ar Plasma

Ham, Yong-Hyun,Efremov, Alexander,Min, Nam-Ki,Lee, Hyun Woo,Yun, Sun Jin,Kwon, Kwang-Ho IOP Publishing 2009 Japanese journal of applied physics Vol.48 No.8

Etching Characteristics and Mechanism of ZnO and Ga-Doped ZnO Thin Films in Inductively Coupled HBr/Ar/CHF₃Plasma

Ham, Yong-Hyun,Efremov, Alexander,Lee, Hyun-Woo,Yun, Sun Jin,Min, Nam Ki,Kim, Kwangsoo,Kwon, Kwang-Ho IOP Publishing 2010 Japanese journal of applied physics Vol.49 No.8

Investigating the accuracy of mandibulectomy and reconstructive surgery using 3D customized implants and surgical guides in a rabbit model

Min Keun Kim,Min Ji Ham,Won Rae Kim,Hyung Giun Kim,Kwang Jun Kwon,Seong Gon Kim,Young Wook Park 대한악안면성형재건외과학회 2023 Maxillofacial Plastic Reconstructive Surgery Vol.45 No.-

Background This study aimed to analyze the accuracy of the output of three-dimensional (3D) customized surgical guides and titanium implants in a rabbit model, and of mandibulectomy, reconstructive surgery, and surgical outcome; additionally, the correlation between surgical accuracy and surgical outcomes, including the differences in surgical outcome according to surgical accuracy, was analyzed. Results The output of implants was accurately implemented within the error range (− 0.03–0.03 mm), and the surgical accuracy varied depending on the measured area (range − 0.4–1.1 mm). Regarding surgical outcomes, angle between the mandibular lower borders showed the most sensitive results and distance between the lingual cusps of the first molars represented the most accurate outcomes. A significant correlation was noted between surgical accuracy in the anteroposterior length of the upper borders pre- and postoperatively and the angle between the mandibular lower borders (regression coefficient = 0.491, p = 0.028). In the group wherein surgery was performed more accurately, the angle between the mandibular lower borders was reproduced more accurately (p = 0.021). A selective laser melting machine accurately printed the implants as designed. Considering the positive correlation among surgical accuracy in the mandibular upper borders, angle between the mandibular lower borders, and more accurately reproduced angle between the mandibular lower borders, the angle between the mandibular lower borders is considered a good indicator for evaluating the outcomes of reconstructive surgery. Conclusion To reduce errors in surgical outcomes, it is necessary to devise a positioner for the surgical guide and design a 3D surgical guide to constantly maintain the direction of bone resection. A fixed area considering the concept of three-point fixation should be selected for stable positioning of the implant; in some cases, bilateral cortical bone fixation should be considered. The angle between the mandibular lower borders is a sensitive indicator for evaluating the outcomes of reconstructive surgery.

산림치유 효능물질 함량에 관한 연구

함광준(Kwang-Joon Ham),박근영(Keun-Young Park),김민수(Min-Su Kim),송재모(Jae-Mo Song),이상수(Sang Soo Lee),옥용식(Yong Sik Ok) 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.6

The biogenic emission of the atmospheric volatile organic compounds (VOCs) from the forests is dominated by monoterpenes. This study investigated the changes in the concentration of monoterpenes distributed in various types of forest near the Gangwon Nature Environment Research Park, Hongcheon, Gangwon Province, Korea. Samples were collected from the three sites of different types of forest, including coniferous, broadleaved and mixed forests. Additionally, the seasonal and daily changes of monoterpene compounds were monitored. Our results found the several types of monoterpene such as α-pinene, β-pinene, camphene, d-limonene, p-cymene and α-terpinene. The highest total concentration of terpene compounds was observed in the coniferous forest. For the summer season, the total concentration of terpene compounds was highest in coniferous and mixed forests, and that was also highest in broad-leaved forest for the autumn.