Microsurgical strategies for small unruptured dorsal internal carotid artery aneurysms

Kanghee Ahn,Woong-beom Kim,You-Sub Kim,Sung-Pil Joo,Tae-Sun Kim 대한뇌혈관외과학회 2023 Journal of Cerebrovascular and Endovascular Neuros Vol.25 No.4

Objective: This study aimed to develop microsurgical strategies based on the anatomical relationship between dorsal internal carotid artery (ICA) aneurysms, the falciform ligament (FL), and the anterior clinoid process (ACP). Methods: Between 2017 and 2022, 25 patients with unruptured dorsal ICA aneurysms (less than 4 mm in diameter) underwent microsurgical direct clipping. These cases involved the left ICA (n=17) and the right ICA (n=8), with a mean aneurysm size of 3.3 mm (range, 2.5 to 4 mm). We used computed tomography angiography (CTA) and digital subtraction angiography to elucidate the anatomical relationship between dorsal ICA aneurysms and other structures. All procedures involved an ipsilateral pterional approach with securement of the ipsilateral cervical ICA for proximal control. Results: Among the 25 dorsal ICA aneurysms, 8 (32%) were clipped without the FL being incised. Another 5 (20%) were clipped solely after the FL was cut. For the remaining 12 cases, the aneurysms were successfully clipped following FL incision and partial ACP removal. Patients exhibited favorable postoperative recoveries with good outcomes, and postoperative CTA revealed complete aneurysm clipping without any residual remnants. Conclusions: We were able to perform clipping without removing the ACP in 13 patients (52%), and in 8 of these (32%), the clipping was carried out directly without cutting the FL. Microsurgery, coupled with proximal control of the cervical ICA, can serve as a viable alternative for patients with small dorsal ICA aneurysms, especially when endovascular treatment options are limited, and 3D CTA confirms a clear anatomical relationship with the ACP.

Design and Implementation of a Delay-Guaranteed Motor Drive for Precision Motion Control

Kanghee Kim,Minyoung Sung,Hyun-Wook Jin IEEE 2012 IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS - Vol.8 No.2

<P>This paper proposes a systematic design approach for a precision-guaranteed motion control system. We develop a delay-guaranteed motor drive with our new software implementation and real-time Ethernet, which can be used as a building block to build up a multi-axis motion control system. Our drive software implementation provides a probabilistic guarantee on drive-local processing delays to motor actuation, while real-time Ethernet provides a deterministic guarantee on message communication delays from a motion control host to each drive. In the paper, we address the precision of a motion control system in two terms: host cycle time and simultaneous actuation deviation. The host cycle time is a period with which the host can periodically release motor control messages while the average drive utilization does not exceed 1, and the simultaneous actuation deviation is the difference between the earliest and the latest actuation at different drives in response to the same message. In our approach, the main objective is to minimize the periods of tasks in each drive, using our stochastic analysis, which gives us a minimum possible host cycle time. Together with an existing delay analysis of real-time Ethernet, we analyze the end-to-end delay from message release to motor actuation and in turn the simultaneous actuation deviation. Through experiments, we show that for various requirements on the deadline miss probabilities of the tasks, we can successfully reduce the host cycle time and evaluate the resulting distribution of the simultaneous actuation deviation depending on the number of drives.</P>

Creating high CO/CO₂ selectivity and large CO working capacity through facile loading of Cu(I) species into an iron-based mesoporous metal-organic framework

Kim, Ah-Reum,Yoon, Tae-Ung,Kim, Seung-Ik,Cho, Kanghee,Han, Sang-Sup,Bae, Youn-Sang Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.348 No.-

<P><B>Abstract</B></P> <P>Achieving both high CO/CO<SUB>2</SUB> selectivity and large CO working capacity in an adsorbent is very challenging. In this work, we have loaded Cu(II) species into large pores of an iron-based metal-organic framework (MOF) with a large surface area and reduced them into Cu(I) species under mild conditions by utilizing Fe(II) sites in the pores. Remarkably, the Cu(I)-incorporated MOF (0.9Cu@MIL-100) exhibits a high CO/CO<SUB>2</SUB> selectivity (29 at 100 kPa) and a large CO working capacity (1.61 mmol/g at 10–100 kPa) simultaneously, which has not been observed for previously reported adsorbent materials. Moreover, 0.9Cu@MIL-100 also presents very high CO/CH<SUB>4</SUB> and CO/N<SUB>2</SUB> selectivities (87 and 677). Furthermore, breakthrough and cyclic adsorption-desorption experiments confirm that this material can efficiently separate CO/CO<SUB>2</SUB> mixtures under dynamic mixture flow conditions and can be easily regenerated under mild conditions. This study provides a new strategy for developing adsorbents with both high CO/CO<SUB>2</SUB> selectivities and large CO working capacities.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cu(I) species were incorporated into an iron-based metal-organic framework (MOF) through a facile method. </LI> <LI> The Cu(I)-loaded MOF exhibits high CO/CO<SUB>2</SUB> selectivity and large CO working capacity simultaneously. </LI> <LI> This MOF also exhibits very high CO/CH<SUB>4</SUB> and CO/N<SUB>2</SUB> selectivities. </LI> <LI> This MOF shows good CO/CO<SUB>2</SUB> separation and regeneration performance under realistic conditions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Fine Control of Water-Adsorption Properties of Crystalline Microporous Aluminophosphates by Changing Porous Structure and Framework Composition for Application in Water Adsorption Chiller

Cho, Kanghee,Kim, Sang Kyum,Lee, Eun Kyung,Kim, Jong-Nam American Scientific Publishers 2017 Journal of nanoscience and nanotechnology Vol.17 No.8

<P>We studied the water-adsorption properties of crystalline aluminophosphates (in brief, 'AlPO4') containing ordered micropores, focusing on the effects of porous structure and heteroatoms incorporated in AlPO4 frameworks. For this investigation, AlPO4 with AFI-and CHA-type structures were hydrothermally synthesized. Also, the AFI-AlPO4 had Si, Fe, Mg, Co, or Cr incorporated at controlled amounts (0-5 mol%). Water adsorption isotherms of the AlPO4 samples were taken at 308 K, showing S-shape curve which is typical characterization of nanomaterial containing uniform nanopores. The amount of water adsorbed in AlPO4 was dependent on the specific surface area. The CHA-AlPO4 exhibited much higher water adsorption capacity than the AFI-AlPO4. The inflection-point humidity of the S-curve was also dependent on the microporous structure. In the case of AFI-AlPO4, the inflection point differed markedly depending on the amount and type of the heteroatoms incorporated in the frameworks. In a group with same micropore structure, the S-curve inflection point decreased in the order of 'solely aluminophosphate'> 'Co-doped' approximate to 'Crdoped' > 'Fe-doped'> 'Mg-doped'> 'Si-doped.' The decrease in the inflection point humidity was found to be positively correlated to the amount of the heteroatom incorporated. Different inflection point humidities might be attributed to changes in the affinity between the AlPO4 framework and water molecules as a result of incorporation of heteroatoms. The results of this study show that it is possible to control the water adsorption properties of AlPO4 precisely, which would be very helpful in developing suitable water adsorbents for use in water adsorption chilling systems under specific working conditions.</P>

중급과정의 피아노 교육에 관한 연구

김강희 ( Kanghee Kim ) 한국피아노교수법학회 2005 음악교수법연구 Vol.1 No.-

Piano study, an essential extracurricular activity to Korean children, is a basic for music education in Korea. Even with its popularity. There is an urgent need for developing educational theory including definition and requirements of levels, roles of teachers and attitude of students. In addition, we need to develop various repertoire for the intermediate level and widen musical experiments. Therefore, the writer tries to initiate the establishment of the music educational theory of the intermediate level in Korea. To do so, the writer investigates specialized books in piano pedagogy field and methods by publishing companies through the inside and outside of the country. The writer defines the intermediate level and analyzes intermediate methods. Moreover, the problems, goals of piano lessons, roles and ability of piano teachers, and selection of Intermediate repertoire are examined. Future study areas are as follows: 1) more research on the intermediate repertoire; 2) grade the intermediate repertoire; 3) develop textbooks for the piano pedagogy that are suited for Korean situations; and 4) develop systematic teaching guide.

Media switching system for various environments using embedded streaming player

Sangok Kim,Kanghee Lee,Zhefan Jiang,Hyunchul Bae,Sangwook Kim 대한전자공학회 2005 ITC-CSCC :International Technical Conference on Ci Vol.2005 No.1

한국피아노교수법학회논문집 : 베토벤 피아노 소나타 No. 31, Op. 110 Ab Major의 연구

김강희 ( Kanghee Kim ) 한국피아노교수법학회 2007 음악교수법연구 Vol.3 No.-

The great composer Ludwig van Beethoven composed piano sonatas as a pianist. The piano sonata No.31, Op.110 Ab major is the only major work with no dedication. It is the most continuous work of all his piano sonatas. He manipulated tonal areas through this piano sonata No.31, Op.110 Ab major. This sonata is an incredible work of art in the respects of the range of musical style and embracing emotion, the range and expressive effectiveness. The motivic relationships of this sonata are extraordinary. Beethoven compared the texture between fugue and homophony. Beethoven borrowed two Austrian songs such as "Our cat``s had kittens" and "I``m a wretch, you``re a wretch" to the second movement of this sonata. He also used Recitativo in manner of Baroque style with poignant and intense mood. Tempo has changed 7 times and Bebung effect of clavierchord was used. Beethoven alsoborrowed "Es ist volbracht", No. 58 from J. S. Bach`` St. John Passion. The moment of deepest despair and Christ``s final words from the cross are described. In tonic major, the first Fugue is started and climax on V7/I. After the second Arioso, the second Fugue is played in reverse form and ending in a huge affirmation of Ab Major with ff. The tonal areas of whole sonata is Ab major. Beethoven emphasized the Db Major as IV. In the exposition, there is an emphasis on I and IV chords in both key areas. These chords are stressed several times with the third on the top. The notes of Db and D, Fb and F are conflicted in several times to describe the struggling life of human being. The penultimate harmony of the first movement is crucial and represented the clash between F and Fb. The first fugue is seemed the resolution of the tonality. The first fugue was divided into three sub-sections. The second Arioso is shown in the new key of g minor. After the final chord is altered to be G major, the second Fugue has shown in logical manner. Through the tonal ambiguity of tonal area, the harmony is embraced to reenforce the tonic. The motive of the first theme of the first movement is appeared through the whole sonata. The downward motion of third is sequenced several times. The fugue subject is derived from the first theme of the first movement. It omits the opening melody note C. Beethoven wrote this sonata as a drama through the fugue and homophony. The function of the fugue is not only a contrapuntal working out of the subject, but to return to the homophonic texture of the recapitulation of the first movement. After the hopeless first Arioso, the reversed fugue subject has stated. Beethoven manipulated the subject in manner of the augmentation and diminution. Finally, Beethoven glorified the God through the arpeggio of 5 octaves with ff.

연구로용 시험연료 집합체의 수중 진동특성 실험 및 결과

이강희(Kanghee Lee),강흥석(Heungseok Kang),김재용(Jaeyong Kim),임정식(Jungsik Yim),김현중(Hyunjung Kim) 한국소음진동공학회 2013 한국소음진동공학회 학술대회논문집 Vol.2013 No.10

모바일 플랫폼을 위한 네트워크 환경 측정 시스템 설계 및 구현

김강희(Kanghee Kim),여진주(Jinjoo Yeo),김진혁(JinHyuk Kim),최상방(SangBang Choi) 대한전자공학회 2013 전자공학회논문지 Vol.50 No.2

모바일 네트워크 사용량이 급증함에 따라 트래픽 수요 문제를 해결하기 위한 많은 연구가 이뤄지고 있다. 특히 네트워크 환경 측정 분야는 정확한 분석을 통해 네트워크상에 발생되는 문제들의 원인을 찾아냄으로써 트래픽 수요 문제를 해결할 수 있는 기반을 제공한다. 특히 최근 스마트폰의 수요가 늘어남에 따라 모바일 플랫폼 특성이 네트워크에 미치는 영향을 고려한 측정시스템이 필요하다. 이에 본 논문에서는 모바일 플랫폼을 위한 네트워크 환경 측정 시스템을 설계하였다. 설계된 시스템은 클라이언트를 통하여 얻은 패킷의 정보를 통하여 패킷 전송간의 지연시간과 throughput을 실시간으로 계산한다. 그리고 측정시 클라이언트인 모바일 단말기에 요구되는 계산량을 줄임으로써 모바일 단말기에 걸리는 부하를 최소화하였다. 설계한 시스템을 통하여 네트워크 자원을 최대로 사용하였을 시 Wi-Fi 망이 3G 망보다 짧은 전송지연시간, 높은 최대 throughput, 낮은 손실률을 가지고, Android가 iOS보다 짧은 전송지연시간과 높은 최대 throughput을 가지며, UDP가 TCP보다 긴 전송지연시간, 높은 최대 throughput을 가진다는 것을 확인하였다. As a rapid increase of mobile network usage, many studies on solution for network traffic’s demand problem have been done. Especially network environment measurement area provides basis for solving network traffic’s demand problem by finding causes of problems through accurate network analysis. However, as increase of demand for smartphone, we should consider effects of mobile platform’s property measuring mobile network. In this paper, we design a network traffic measurement system considering mobile platform. Through the information from packets, this system calculates packet transmission delay and throughput. We minimize computation cost required for a mobile device that is a client in this system. When fully using network resources, we found that Wi-Fi has shorter transmission delay, higher maximum throughput and lower loss rate than 3G, Android has shorter transmission delay and higher maximum throughput than iOS, and UDP has longer transmission delay and higher maximum throughput through this system.

전후륜 양력비에 따른 고속주행 안정성 연구

김강희(KangHee Kim),김우철(WooChul Kim),남성현(SungHyun Nam),전성현(SungHyun Jeon) 한국자동차공학회 2019 한국자동차공학회 부문종합 학술대회 Vol.2019 No.5

The Lift acts in the direction corresponding to the vertical direction during the straight running. There is a difference in the high speed stability of the vehicle depending on the lift coefficient (CL). That is, when CL is higher, the high speed stability is more unstable, and when it is lower, stability is more improved. In this paper, I confirmed the correlation between lift coefficient and high speed stability. Also, the lift coefficient is related to the design of the vehicle. If we set the lift coefficient properly, we will be able to develop the vehicle efficiently considering performance and design.