특수 환경에 대한 유리섬유/비닐에스테르 수지 복합재료의 내구성에 관한 연구

이승열 釜慶大學校 大學院 2006 국내석사

해남 순신 광산의 금광화작용과 천열수계의 특성

이승열 부산대학교 2011 국내석사

The Sunshin gold mine is hosted in Cretaceous Hwangsan tuff and is known to be related with epithermal system in the late stages of volcanic events in Haenam district, southwestern Korean peninsula. This study documents gold mineralization of an epithermal system in volcanic environment and the evolutional behavior of hydrothermal fluids, focusing on mineral paragenesis, fluid inclusions and stable isotope study. Based on vein mineralogy and paragenesis, the hydrothermal mineralized quartz veins crosscutting and cementing the host Hwangsan tuff are grouped into three main stages: Stage I is characterized by the deposition of sulfides(mainly pyrite, spharerite, galena and chalcopyrite) with crystalline quartz. Stage II is considered as the main mineralization stage precipitating sulfides (such as goldfieldite, tennantie, bismuthinite and covellite), adularia, and gold-beraing ore minerals together with chalcedonic veins. Gold appears to have been precipitated dat the later stage II. Native gold is extremely rare, mainly occurring as electrum and Au-Ag tellurides such as hessite, calaverite, and sylvanite. Stage III is characterized by the deposition of quartz, calcite and various clay minerals. The host rocks near bonanza have undergone phyllic-aduaria-carbonate alteration showing characteristic mineral assemblages that quartz, sericite, illite, adularia, pyrite and calcite are present. Three distinct types of fluid inclusions from quartz veins are associated with alteration and mineralization in the Sunshin gold deposit. The earliest fluid can be represented by Type II fluid inclusions which are vapor-rich and salinity ranged 1.0~4.7wt% with homogenization temperatures (Th) between 146~310℃. These composition and Th indicate that they were trapped at 40~150bars in the P-T phase diagram. The next fluid circulated in the Sunshin hydrothermal system can be represented by Type II which are liquid-rich, salinity 0.5~6.2wt% and Th 136~261℃, indicating that they were trapped at 30~150bars. The last fluid can be represented by Type IV CO2-bearing fluid inclusions which show two separate liquid-CO2 and vapor-CO2 phases at room temperature, suggesting that they were trapped at higher pressure condition than at least 50~60bars. The oxygen isotopic composition of hydrothermal quartz ranged from 5.1 to 7.0‰(SMOW). The hydrogen isotopic composition of fluid inclusions in the same quartz ranged from -82 to 100‰ (SMOW). The δ18Owater values of water that precipitated the quartz have been calculated. The calculated oxygen isotopic composition of the water ranges from -1.9 to -3.8‰ at 250℃ and from -4.7 to -6.6‰ at 200℃. The Sunshin gold mine can be characterized by relatively indistinctive wall-rock alteration nature, unpredictably and randomly scattered quartz veins, Fe-poor sphalerite composition, occurrence of adularia, and the absence of sulfate minerals, implying a low-sulfidation type of mineralization. The low-sulfidation epithermal system formed by circulating fluids with neutral pH and low sulfur fugacity in reduced environment were influenced by meteoric water with some degree of mixing of magmatic water or metamorphic water. The mineralized fluid with a 5 wt% salinity at 250℃ had commenced the Sunshin epithermal system at around 100-150bars and continued until 150℃.

공예교육과 현대공예의 양상 : 고등학교 미술과 교육과정을 중심으로

이승열 동국대학교 교육대학원 2001 국내석사

In my paper, I shall grasp introduction stage of craft education in "course of study of art" in Korean education system, and compare the craft education with the aspects of Korean contemporary craft that has undergone changes and made progress since liberated from Japan. To accomplish the purpose of my paper reasonably, I have limited the study range to a period from 1946, in which U.S. military administration enforced the operation of compulsory school law, to the end year of 6th course of study, and examined chronologically the issues from changes of concept in craft education field. The study range is also the period in which Korean craft has groped for its own craft spirit in new independent environment for a basis through the modem stage of colonial establishment. In the second chapter, I have examined the function and meaning of craft education to premise the idea of craft education in art education. In consideration of the introduction of craft education in western school system, the educational terms meaning training of hand such as handicraft and manufacture have been recognized as a method of process of thinking, knowledge development, character building and whole cultivation. For that reason, especially, John Dewy has approved that craft education has had intrinsic value as an Art experience. Such intention to accomplish the educational purpose through training of hand and things has become important educational idea in craft education. In the third chapter, I have researched trend of Korean contemporary craft after independence. In regarding the aspects of Korean contemporary craft, the most notable features are diversifying of presentation, breaking with traditional craft and intensifying of confrontation between function and shape in short. During the modern era, the Korean craft had passed through conditions by which traditional craft spirit had been distorted in a stage of modernization without independence. After liberation, as design concept for mass production has been introduced, Korean craft has positively accepted trend of western modern art to search for a solution to problem of spirit of craft manufacture, and made a general movement with experiments of new formative art education. The formative art education was American course of study by idea of German Bauhaus, and brought about perception regarding traditional craft to be pre-modern. In this way, during the course of reforming art society to be fine art-oriented, Korean contemporary craft has shown tendency that craft has been partial to basis of formative art disregarding the fundamental principals of craft. On the one hand, craft education of Korean course of study has not reflected craft education ideology with vague terms and equivocal notions as the first course of study had been adopted by U.S. military administration, and those unclear concepts had continued until the first course of study during sixties. Such conditions had continued until the end of the second course of study. In the third course of study, for the first time, the concept of craft seemed to be settled as art education was influenced by trend of education called structure of knowledge that was scholarship-oriented. However, from the 4th course of study, the craft education field was presented as it was absorbed by the field of design that was newly introduced. From the 5th course of study, it was been completely integrated by the field of design and established with concept of craft education putting emphasis on application to practical life. The craft education in 6th course of study, which continued in the field of design, was organized into a system of contents that made much of originality, object and function, and gave consideration to formative beauty. As I understood the features of craft education field that has changed so far, first of all, I found that the purpose of craft education has been included among fields of design education premising mass production, so that the purpose has not indicate the fundamental craft spirit. Additionally, the organized comprehension of traditional craft has been generally altered to the field of appreciation. In the same period, to get status in current of contemporary art, the artist-oriented principle reserving function for formation and the experiments disregarding function of manufacture idea have made mainstream in Korean contemporary craft's phase. Such aspects of contemporary craft have made a cause of continuous problem in connecting traditional craft and contemporary craft that have been broken off and in groping for course of fundamental principal of craft manufacture. The features of contemporary craft that I have examined show much difference from the concept of craft emphasized in the filed of design from course of study of art in school education. Due to basic understanding of traditional craft in field of appreciation, the problem of necessity for connection between contemporary craft and craft education results in a problem that limits understating original spirit with traditional background and aboriginality with material and manufacture, so that it is required to connect systematically contemporary craft and course of study of art in general.

Voice quality improvement for hands-free narrowband speech communication

이승열 서울대학교 대학원 2008 국내박사

무인결제시스템의 도입의도에 미치는 요인에 관한 연구 : 확장된 통합기술수용이론(UTAUT-2)을 중심으로

이승열 중앙대학교 산업·창업경영대학원 2021 국내석사

This study attempted to demonstrate the factors affecting the intention of introducing an unmanned payment system, focusing on those who have started or intend to start a service company. At this time, a more significant study was conducted based on the Integrated Technology Acceptance Model (UTAUT-2), and independent variables were adopted and formed by performance expectations, effort expectations, social influence, promotion conditions, hedonic motivation, price utility, and perceived risk. Research implications were added by verifying differences according to gender, age and start-up experience. in this study, the moderating effect of payment habits was verified by differentiating it from previous studies. The results of this study are summarized as follows. First, the hypothesis that performance expectations for unmanned payment systems have a positive(+) effect on the intention of introduction was not supported, but payment habits showed a moderating effect in the relationship between performance expectations and intention of introduction. Therefore, in the case of the introduction of unmanned payment system technology that replaces existing technology, which is not a completely new technology, it can be seen that it has a moderating effect by expecting results based on the formation of payment habits. Second, the hypothesis that effort expectations for unmanned payment systems have a positive(+) effect on the intention of introduction was not supported, and payment habits did not show a moderating effect in the relationship between effort expectations and intention of introduction. Effort expectations do not show any significant impact and regulatory effect on the intention of introducing unmanned payment systems, which can be seen as not easily formed due to the rapid change in unmanned payment systems. Third, the hypothesis that the social impact on unmanned payment systems has a positive effect on the intention of introduction was supported, and payment habits showed a moderating effect in the relationship between social influence and introduction intention. The higher the level of payment habits formed according to payment experience, the easier it is to respond to the social atmosphere, so it can be reviewed that the intention to use the unmanned payment system within the company can be controlled by the social influence depending on the payment habits. Fourth, the hypothesis that facilitation conditions for unmanned payment systems have a positive effect on the intention of introduction was not supported, and that payment habits showed no adjustment effect in the relationship between the facilitation conditions and intention of introduction. Additionally, the facilitation conditions did not show any moderating effect according to gender, age, or entrepreneurship experience. Accordingly, even if conditions that can promote the unmanned payment system exist, it can be seen that it is difficult to significantly affect the intention of the introduction. In addition, it can be attributed to the large endogenous effects of respondents in the case of payment habits, gender, age, and start-up experience. Fifth, the hypothesis that hedonic motivation for unmanned payment systems affects the intention of introduction (+) was supported, and payment habits showed a controlling effect in the relationship between hedonic motivation and intention of introduction. In addition, hedonic motivation did not shown difference by age, gender, or start-up experience, and there was no adjustment effect between hedonic motivation and introduction intention according to age, gender, or start-up experience. Payment habits formed according to payment experience tend to develop into habits with higher hedonic motives. Accordingly, it can be seen that payment habits have a moderating effect on the relationship between hedonistic motives and introduction intentions. In addition, the reason for the difference according to age can be attributed to the inconvenience of the unmanned payment system for older people, resulting in differences in hedonic motives. Sixth, the hypothesis that the price utility for unmanned payment systems affects the intention of introduction (+) was supported, and the payment habit did not show a adjustment effect in the relationship between the price utility and the intention of introduction. In addition, there was no difference in price utility according to gender, age, and start-up experience. This can be seen that the higher the price utility of the unmanned payment system, the higher the intention to use it. And Also, there is no moderating effect between the price utility and the intention to introduce the unmanned payment system according to the payment habits. There is no correlation between the price utility of the unmanned payment system according to the payment habits and the intention to introduce it, because It is judged that the price in the unmanned payment system is the same as the transaction in the general transaction from the point of view of the general consumer. In addition, gender, age, and start-up experiences are not showing any difference or adjustment effect on price utility, which can be seen as a result of the general commercialization of unmanned payment systems. Seventh, the hypothesis that perceived risks to unmanned payment systems has a negative affect on the intention of introduction was supported, and that payment habits showed no regulatory effect in the relationship between perceived risks and the intention of introduction. Additional perceived risks did not show any differences or adjustments depending on gender, age, or start-up experience. The results of this study can be seen that the greater the pre-recognized risk of unmanned payment systems, the lower the intention to use them. And there is no adjustment effect between price utility and intention of introduction based on experience-based payment habits for unmanned payment systems. There is no correlation between perceived risk of the unmanned payment system according to payment habits and intention of introducing a payment system. This can be interpreted as a relationship that inhibits the perceived risk by increasing of the general payment experience. so payment habits in the unmanned payment system can be seen as not moderating the relationship between perceived risk and intention of introduction. In addition, there were no differences and moderating effects according to gender, age, and entrepreneurship experience. Eighth, in case of payment habits for unmanned payment system, difference can be checked according to gender and age, but additionally considering the adjustment effects according to gender, age, and start-up experience, there seem to be not much effect on difference of introduction intention by means of gender characteristic, forming of experience according to age, perceived usefulness. In particular, there are no significant differences in payment habits, gender, age, and start-up experience, which have been verified as a moderating effect on the relationship between each introduction factor and the intention of introduction. As we enter the 4th industrial revolution era after the 3rd industrial revolution era, the commercialization and popularization of the unmanned payment system is generally achieved, so the difference among each groups does not appear to be evident. 본 연구는 서비스업체를 창업하였거나 창업하고자 하는 사람들을 중심으로 무인결제시스템 도입의도에 영향을 미치는 요인에 대한 실증분석을 시도하고자 하였다. 이때, 통합기술수용모형(UTAUT-2)을 바탕으로 더욱 유의성 있는 연구를 진행하고자 하였으며, 독립변수로는 성과기대, 노력기대, 사회적 영향, 촉진조건, 쾌락적 동기, 가격효용, 인지된 위험으로 채택하여 구성하였다. 성별, 연령, 창업경험에 따른 차이를 검증하여 연구적 함의성을 더하였으며, 본 연구에서는 기존 선행연구들과 차별화하여 결제습관의 조절효과를 검증하였다. 본 연구 결과를 요약하면 다음과 같다. 첫째, 무인결제시스템에 대한 성과기대가 도입의도에 정(+)의 영향을 미친다는 가설은 지지되지 않았으나, 성과기대와 도입의도에 관계에서 결제습관은 조절효과를 보이는 것으로 나타났다. 이에 온전히 새로운 기술이 아닌 기존 기술을 대체하는 무인결제시스템기술 도입의 경우, 결제습관의 형성에 기반하여 성과를 기대하게 되어 조절효과를 나타냄을 알 수 있다. 둘째, 무인결제시스템에 대한 노력기대가 도입의도에 정(+)의 영향을 미친다는 가설은 지지되지 않았으며, 노력기대와 도입의도에 관계에서 결제습관은 조절효과를 보이지 않는 것으로 나타났다. 노력기대는 무인결제시스템의 도입의도에 대하여 유의한 영향과 조절효과를 보이지 않고 있는데, 이는 무인결제시스템의 급속한 변화 추이에 따라 무인결제시스템의 결제습관이 쉬이 형성되기 쉽지 않으므로 유의한 조절효과 관계가 나타나지 않는 것으로 볼 수 있다. 셋째, 무인결제시스템에 대한 사회적 영향이 도입의도에 정(+)의 영향을 미친다는 가설은 지지되었으며, 사회적 영향과 도입의도에 관계에서 결제습관은 조절효과를 보이는 것으로 나타났다. 결제경험에 따라 형성된 결제습관이 높은 수준일수록 사회적인 분위기에 쉽게 대응할 수 있으므로, 결제습관에 따라 사회적 영향이 무인결제시스템을 업체 내에 이용하고자 하는 의도가 조절될 수 있음을 검토해볼 수 있다. 넷째, 무인결제시스템에 대한 촉진조건이 도입의도에 정(+)의 영향을 미친다는 가설은 지지되지 않았으며, 촉진조건이 도입의도에 관계에서 결제습관은 조절효과를 보이지 않는 것으로 나타났다. 추가적으로 촉진조건은 성별, 연령, 창업경험에 따른 조절효과 또한 나타나지 않았다. 이에 따라, 무인결제시스템을 촉진할 수 있는 조건들이 존재하더라도 도입의도에 유의한 영향을 미치기에는 어려운 것으로 볼 수 있다. 또한, 결제습관과 성별, 연령, 창업경험의 경우 응답자들의 내생적인 영향이 크기 때문으로 볼 수 있다. 다섯째, 무인결제시스템에 대한 쾌락적 동기가 도입의도에 정(+)의 영향을 미친다는 가설은 지지되었으며, 쾌락적 동기와 도입의도에 관계에서 결제습관은 조절효과를 보이는 것으로 나타났다. 추가적으로 쾌락적 동기는 연령, 성별, 창업경험에 따른 차이가 나타나지 않았으며, 연령, 성별, 창업경험에 따른 쾌락적 동기와 도입의도간의 조절효과 또한 나타나지 않았다. 결제경험에 따라 형성된 결제습관은 쾌락적 동기가 높을수록 습관으로 발전되기 쉬운데, 이에 따라 쾌락적 동기와 도입의도 간의 관계를 결제습관이 조절적 영향을 보인다고 볼 수 있다. 또한, 연령에 따른 차이를 보이는 이유는 고연령층일수록 무인결제시스템이 불편하여 쾌락적 동기에 차이가 발생하기 때문으로 볼 수 있다. 여섯째, 무인결제시스템에 대한 가격효용이 도입의도에 정(+)의 영향을 미친다는 가설은 지지되었으며, 가격효용이 도입의도에 관계에서 결제습관은 조절효과를 보이지 않는 것으로 나타났다. 추가적으로 가격효용은 성별, 연령, 창업경험에 따른 차이가 나타나지 않았다. 이는 무인결제시스템의 가격에 대한 효용이 높을수록 이용하고자 하는 의도가 높아진다고 볼 수 있다. 그리고 무인결제시스템에 대한 결제습관에 따른 가격효용과 도입의도 간의 조절효과는 나타나고 있지 않다. 결제습관에 따른 무인결제시스템의 가격효용과 도입의도의 연관관계는 나타나고 있지 않는데, 이는 일반적인 소비자 입장에서 무인결제시스템에서의 가격은 일반적인 거래에서의 거래와 같기 때문으로 판단된다. 또한, 성별, 연령, 창업경험은 가격효용에 대해 차이 및 조절효과를 보이지 않고 있다고 볼 수 있는데, 이는 무인결제시스템의 일반적인 상용화에 따른 결과로 볼 수 있다. 일곱째, 무인결제시스템에 대한 인지된 위험이 도입의도에 부(-)의 영향을 미친다는 가설은 지지되었으며, 인지된 위험이 도입의도에 관계에서 결제습관은 조절효과를 보이지 않는 것으로 나타났다. 추가적으로 인지된 위험은 성별, 연령, 창업경험에 따른 차이와 조절효과가 나타나지 않았다. 이러한 연구결과는 무인결제시스템의 사전에 인지된 위험이 클수록 이용하고자 하는 의도가 낮아진다고 볼 수 있다. 그리고 무인결제시스템에 대해 경험에 기반한 결제습관에 따른 가격효용과 도입의도 간의 조절효과는 나타나고 있지 않다. 결제습관에 따른 무인결제시스템의 인지된 위험과 도입의도의 연관관계는 나타나고 있지 않는데, 이는 일반적인 결제경험이 많을수록 인지된 위험을 오히려 저해하는 관계로 해석될 여지가 있는바 무인결제시스템에서의 결제습관은 인지된 위험과 도입의도 간의 관계를 조절하고 있지 못한 것으로 볼 수 있다. 또한, 성별, 연령, 창업경험에 따른 차이 및 조절효과는 나타나지 않았다. 여덟째, 무인결제시스템에 대한 결제습관의 경우 성별 및 연령에 따라 차이를 확인해볼 수 있으나, 각각 성별, 연령, 창업경험에 따른 조절효과를 추가적으로 고찰하면, 남자와 여자의 성향, 연령에 따른 경험의 형성, 창업경험에 따른 인지된 유용성 등의 차이로 인한 도입의도에 대한 차이는 다소 영향이 없는 것으로 보인다. 특히, 각 도입요인이 도입의도에 미치는 관계 확인 간 조절효과로 검증된 결제습관, 성별, 연령, 창업경험 등은 유의한 차이를 뚜렷이 보이지 못하고 있는데, 이는 3차산업혁명시대를 거쳐 4차산업혁명시대에 접어들며 일반적으로 무인결제시스템의 상용화 및 대중화가 이뤄져 그 차이가 집단 간 뚜렷하게 나타나지 않는 것으로 보인다.

단위 선택을 이용한 한국어 음성 합성기

이승열 서울大學校 大學院 2001 국내석사

GPU의 DRAM 접근 감소를 위한 데이타 재사용 쓰레드 블락 스케줄링

이승열 서울대학교 대학원 2013 국내석사

GPU(Graphics Processing Unit)는 그래픽스 응용을 위해서 개발되었으나, 최근에는 많은 연산이 필요한 일반적인 응용에 사용하기 위한 GPGPU(General Purpose GPU) 구조로 발전이 되고 있다. GPGPU를 통해 병렬 프로그램을 실 행시키면 매우 높은 처리량(throughput)을 얻을 수 있다. 하지만, GPGPU는 내부의 캐시(cache) 사이즈가 매우 적고 여러개의 쓰레드(thread)가 동시에 실 행되기 때문에 매우 높은 DRAM 대역폭(bandwidth)을 요구하고, 메모리 접 근으로 인하여 많은 파워를 소모한다. 최근들어 고성능 GPGPU에 L2 캐시를 탑재하였지만, 제한된 캐시 크기로 인하여 캐시 적중률(cache hit ratio)이 높지 않다. 본 논문에서는 L2 캐시의 효율성을 높이고 DRAM 메모리 접근 횟수를 줄이는 새로운 GPU 쓰레드-블락(thread-block) 스케줄링 방법을 제안한다. 이 스케줄링 방법은 쓰레드-블락 간 사용 데이타의 중복기회를 최대로 높이며, 응 용 프로그램을 조금 수정하는 것으로 쉽게 구현이 가능하다. Hotspot과 행렬 곱셈 벤치마크 프로그램에 적용을 하였고, DRAM 접근 횟수를 각각 최대 39% 와 84% 감소시켰다.

Directional launching methods of surface plasmon in nanoslits and applications

이승열 서울대학교 대학원 2014 국내박사

Surface plasmon polaritons (SPPs), known as quasi-particles generated by a collective oscillation of photons and electrons, have been studied by numerous researchers due to their various fascinating properties such as sub-wavelength confinement characteristics and strong electromagnetic field enhancement near metal surface. Indeed, such characteristics are quite demanded to design a novel photonic devices for future technologies such as highly integrated photonic circuit and optical storage system with ultra-high density. Hence, numerous studies have been reported about optical devices based on the physical characteristics of SPPs, so-called “plasmonic devices.” Although they are not yet combined to integrated system which can overcome the conventional computing system operated by electrons, optical or quantum computing via SPPs is still an impressive issue in nanophotonics. One of the necessary parts of optical computing is a switching of SPP source. The works done in this dissertation are focused on the physical mechanism and structural design of nanostructures such as nanoslit and nanoaperture which can be used to switch SPP source. After brief introduction, the first part of this dissertation discusses on the various methods for directional switching of SPP excitation from nanoslit geometry. In broad separation, two types of directional switching mechanisms are demonstrated: the first one is a plasmonic directional switching which can be modulated by polarization modulation. It is shown that the excited SPPs from nanoslit can be unidirectionally launched without any asymmetry of neither geometry nor incident momentum at certain polarization state when the light illuminates obliquely along the parallel-to-slit direction. To explain such a novel type of SPP excitation phenomenon, an induced current model that can explain an aspect of SPP excitation from nanoslit for TE and TM polarization illumination is proposed. Then, appropriate experimental results are followed to verify the possibility and performance of unidirectional SPP excitation. Then, the second type of plasmonic directional switching method, which can be modulated by phase modulation, is discussed. When two beams illuminate obliquely to nanoslit, it is found that excited SPPs from nanoslit have either symmetric or anti-symmetric profile according to the relative location between node of interference pattern and center of slit. After finding the optimized condition of nanoslit geometry which can efficiently excite both symmetric and anti-symmetric SPPs in nearly same amplitude scale, experimental demonstration of SPP switching is achieved with electromotive phase modulation done by piezo-stage. The origins of both types of switching methods can be explained by the induced charge distribution near the nanoslit. In the second part of this dissertation, various plasmonic devices that use the switching mechanism introduced in the first part of this dissertation are demonstrated. For the realization of optical signal multiplexing and spectrum analyzing in integrated chip scale, it is necessary to develop a plasmonic color splitter which can clearly split the designed region of frequencies. By applying the physical analogy discussed in the first part of this dissertation, theoretical analysis on the plasmonic dichroic splitter that can launch two different frequencies of visible light into an opposite direction is shown for the first application device. In this case, metal-insulator-metal (MIM) waveguide structure is used instead of single interface geometry to form a Fabry-Perot resonator structure at the entrance of SPP coupler. Similar to the work done in the first part, this plasmonic dichoric splitter can also switch their launching directions of SPPs when incident polarization state is changed. Moreover, beaming from surface plasmon source has great potential to generate a subwavelength scale of optical beam. For the second application device, analysis on the plasmonic beaming from plasmonic double spiral bull’s eye geometry is discussed. Chiral geometry pattern of spiral bull’s eye geometry can lead to the polarization dependent characteristics for beam generation. It is shown that the generated beam from spiral bull’s eye can be switched on and off according to the optical polarization of incident light. Such beam switching phenomenon can be explained by the angular momentum change, which is caused by spin-orbital interaction at the nanohole and spiral gratings.

Cooperative Power Management for Chip Multiprocessors using Space-Shared Scheduling

이승열 서울대학교 대학원 2015 국내석사

Nowadays, many-core chips are especially attractive for data center operators to provide cloud computing service models. The trend in operating system designs, furthermore, is changing from traditional time-sharing to space-shared approaches to support recent many-core architectures. These CPU and OS changes make power and thermal constraints becoming one of most important design issues. Additional power management methods and core re-allocation techniques are necessary to overcome the limitations of traditional dynamic voltage and frequency scaling (DVFS). In this thesis, we present a cooperative hierarchical power management for many-core systems running a space-shared operating system. We consider two levels of space-shared system resources: space in the form of cores and physical memory. Recent chip multiprocessors (CMPs) provide group-level DVFS in which the voltage/frequency of cores is managed at the level of several cores instead of every single core. Memory is also allocated by a coarse-grained resource manager to isolate space partitions. Our research reflects these characteristics of CMPs. We show how to integrate core re-allocation and DVFS techniques through cooperative hierarchical power management. The core re-allocation technique considers the data performance in dependence of the core location. In addition, two important factors are performance loss caused by DVFS and the benefit of core re-allocation. We have implemented this framework on the Intel Single Chip Cloud Computer (SCC) and achieve a 27-32% better performance per watt ratio than naive DVFS policies at the expense of a minimal 1-2% overall performance loss. Furthermore, we have achieved a 5-11% higher performance than previous research with a migration technique that uses a naive migration algorithm that does also not consider the migration benefit and data locality. 최근 Cloud Computing 서비스를 제공하는 데이터센터 등에서는 Many-core chip이 기존 Multi-core를 대체하여 사용되고 있으며 Operating System도 Many-core 시스템을 사용할 수 있게 Space-sharing 방식으로 설계가 변경되고 있다. 이러한 추세속에서 기존의 전통적인 DVFS 방식을 이용해서는 Many-core 환경에서 효율적인 전력 사용이 어렵기 때문에 추가적인 전력 관리 방법과 Many-core의 특성을 고려한 Core 재배치 기술이 필요하다. Space-shared OS는 Core와 물리적인 메모리의 구성에 대한 자원 관리를 하는데, 최근의 Chip multiprocessor (CMP) 들은 각각의 Core에서 독립적으로 DVFS를 동작하도록 하지 않고 몇개의 Core들을 그룹화하여 Voltage 또는 Frequency를 함께 변경할 수 있도록 지원하고 있으며 메모리 또한 Coarse-grained 방식으로 독립된 파티션으로 할당 할 수 있게 관리된다. 본 연구는 이러한 CMP의 특성을 고려하여 Core 재배치와 DVFS 기술을 이용한 계층적 전력 관리 시스템을 연구하는데 목표가 있다. 특히 Core 재배치 기술은 Core의 위치에 따른 Data 성능도 함께 고려하고 있다. 이에 추가로 DVFS 성능 손실을 고려한 에너지 효율성 상승과 Core 재배치시 발생할 수 있는 효과를 미리 계산하여 최소한의 성능저하로 더 좋은 에너지 효율성을 얻을 수 있도록 연구를 진행하였다. 또한 실제 구현 및 실험은 Intel에서 출시한 Single-chip Cloud Computer (SCC)에서 진행하였으며 시나리오별로 1-2%의 성능 손실로 Performance per watt ratio가 27-32% 향상되었다. 또한 Migration 효과와 Data 지역성 등을 고려하지 않았던 기존 연구보다 성능이 5-11% 좋아졌다.

혈소판 유래성장인자를 함유한 chitosan/calcium metaphosphate의 골조직재생효과에 관한 연구

이승열 서울대학교 대학원 2001 국내박사