Distribution Contrast for Disentangled Fair Representation

Changdae Oh,Heeji Won,Junhyuk So,Taero Kim,Yewon Kim,Hosik Choi,Kyungwoo Song 한국자료분석학회 2022 한국자료분석학회 학술대회자료집 Vol.2022 No.7

Zebra Refresh: Value Transformation for Zero-Aware DRAM Refresh Reduction

Kim, Seikwon,Kwak, Wonsang,Kim, Changdae,Huh, Jaehyuk IEEE 2018 IEEE computer architecture letters Vol.17 No.2

<P>Refresh operations consume growing portions of DRAM power with increasing DRAM capacity. To reduce the power consumption of such refresh operations, this paper proposes a novel value-aware refresh reduction technique exploiting the abundance of zero values in the memory contents. The proposed <I>Zebra refresh</I> architecture transforms the value and mapping of DRAM data to increase consecutive zero values, and skips a refresh operation for a row containing zero values entirely. Zebra converts memory blocks to base and delta values, inspired by a prior compression technique. Once values are converted, bits are transposed to place consecutive zeros matching the refresh granularity. The experimental results show Zebra refresh can reduce DRAM refresh operations by 43 percent on average for a set of benchmark applications.</P>

The Relationship between Civic Humanism and Calvin’s View of the State

KIM Changdae(김창대) 장로회신학대학교 기독교사상과 문화연구원 2017 장신논단 Vol.49 No.3

본 논문은 종교개혁 당시의 칼뱅의 국가관이 이탈리아 플로렌스의 시민 인문주의에 영향을 받았다는 것을 논증하는 데에 그 목적이 있다. 이를 위해 플로렌스의 인문주의 특징을 살피고, 국가관과 정치관과 관련해서 플로렌스 인문주의자들이 어떤 생각을 가졌는지를 살펴보았다. 이 과정에서 플로렌스 인문주의에 대한 다양한 학자들의 평가를 검토하였다. 여기서 플로렌스의 인문주의의 주요 특징은 고전 지식을 적극적인 정치참여와 통합하려고 했다는 점을 발견할 수 있다. 또한 칼뱅이 활동했던 알프스 북부에서 에라스무스로 대변되는 인문주의 특징도 정치개혁과 무관하지 않음을 고찰했다. 칼뱅은 당시 프랑스 인문주의자들을 통해서 고전 지식을 알게 되었고, 프랑스 인문주의자들은 플로렌스의 인문주의에 매우 큰 흥미를 갖고 있는 자들이었음을 알 수 있었다. 더욱이 칼뱅은 플로렌스의 시민 인문주의를 모델로 해서, 국가 개혁을 시도했던 마틴 부처에 크게 영향을 받았다. 바로 이런 이유들로 해서, 칼뱅은 제네바 개혁에서 국가와 교회를 분리시켰다. 칼뱅은 국가와 교회는 하나님 나라를 위해 동일하게 공헌하는 독립된 기능을 하는 실체로 보았다. 이상의 관찰들은 칼뱅의 국가관이 플로렌스 인민주의에 영향을 받았다는 증거로 이해할 수 있다. 그래서 칼뱅은 도시 전체가 교회라고 주장했던 츠빙글리와는 달랐다고 말할 수 있다. 결국 국가가 하나님 나라를 위해 독특한 역할을 수행한다고 생각한 칼뱅의 국가관은 그의 인문주의 배경과 마틴 부처의 영향을 통해서, 그가 접촉하게 된 플로렌스의 시민 인문주의에 어느 정도 빚을 진다고 주장할 수 있다. 이런 발견은 오늘날 기독교가 국가에 대한 더 많은 고민을 해야 한다는 교훈을 준다. This work has attempted to explore an relationship between Calvin’s view of the state and Florentine civic humanism. For this, attention has been devoted to how Calvin was in contact with civic humanism in Florence in reference to the view of the state. Also, this work has dealt with the characteristics of Florentine civic humanism in order to find any political hints that indicate some influences on Calvin’s view of the state. Basically, the prominent feature of Florentine civic humanism is found in its efforts to integrate the classical learning with active participation in politics. In the process of the argumentation, it has been revealed that Calvin was acquainted with classical learning especially through French humanist who had interest in Florentine humanism. Also, he was greatly influenced by Bucer who sought a reform for the state on the model of Florentine civic humanism. This finding can be regarded as circumstantial evidence that Calvin’s view of the state was in some degree influenced by Florentine civic humanism, with the result of understanding the church and the state as being separate entities contributing to the kingdom of God. In this respect, Calvin, together with Bucer, was different from Zwingli who argued that the Christian city was nothing other than the Christian church. The explanation for Calvin’s positive evaluation of the unique role of the state can be found in his contact with civic humanism through both his humanistic background and Bucer’ influence as previously suggested.

GVTS: Global Virtual Time Fair Scheduling to Support Strict Fairness on Many Cores

Kim, Changdae,Choi, Seungbeom,Huh, Jaehyuk IEEE 2019 IEEE transactions on parallel and distributed syst Vol.30 No.1

<P>Proportional fairness in CPU scheduling has been widely adopted to fairly distribute CPU shares corresponding to their weights. With the emergence of cloud environments, the proportionally fair scheduling has been extended to groups of threads or nested groups to support virtual machines or containers. Such proportional fairness has been supported by popular schedulers, such as Linux Completely Fair Scheduler (CFS) through virtual time scheduling. However, CFS, with a distributed runqueue per CPU, implements the virtual time scheduling <I>locally</I>. Across different queues, the virtual times of threads are not strictly maintained to avoid potential scalability bottlenecks. The uneven fluctuation of CPU shares caused by the limitations of CFS not only violates the fairness support for CPU assignments, but also significantly increases the tail latencies of latency-sensitive applications. To mitigate the limitations of CFS, this paper proposes a <I>global virtual-time fair scheduler (GVTS)</I>, which enforces global virtual time fairness for threads and thread groups, even if they run across many physical cores. The new scheduler employs the hierarchical enforcement of target virtual time to enhance the scalability of schedulers, which is aware of the topology of CPU organization. We implemented GVTS in Linux kernel 4.6.4 with several optimizations to provide global virtual time efficiently. Our experimental results show that GVTS can almost eliminate the fairness violation of CFS for both non-grouped and grouped executions. Furthermore, GVTS can curtail the tail latency when latency-sensitive applications are co-running with batch tasks.</P>

Exploring the Design Space of Fair Scheduling Supports for Asymmetric Multicore Systems

Kim, Changdae,Huh, Jaehyuk IEEE 2018 IEEE Transactions on Computers Vol.67 No.8

<P>Although traditional CPU scheduling efficiently utilizes multiple cores with equal computing capacity, the advent of multicores with diverse capabilities pose challenges to CPU scheduling. For such asymmetric multi-core systems, scheduling is essential to exploit the efficiency of core asymmetry, by matching each application with the best core type. However, in addition to the efficiency, an important aspect of CPU scheduling is fairness in CPU provisioning. Such uneven core capability is inherently unfair to threads and causes performance variance, as applications running on fast cores receive higher capability than applications on slow cores. Depending on co-running applications and scheduling decisions, the performance of an application may vary significantly. This study investigates the fairness problem in asymmetric multi-cores, and explores the design space of OS schedulers supporting multiple fairness constraints. In this paper, we consider two fairness-oriented constraints, <I>minimum fairness</I> for the minimum guaranteed performance and <I>uniformity</I> for performance variation reduction. This study proposes four scheduling policies which guarantee a minimum performance bound while improving the overall throughput and reducing performance variation too. The proposed fairness-oriented schedulers are implemented for the Linux kernel with an online application monitoring technique. Using an emulated asymmetric multi-core with frequency scaling and a real asymmetric multi-core with the big.LITTLE architecture, the paper shows that the proposed schedulers can effectively support the specified fairness while improving overall system throughput.</P>

새 언약 안에서 백성의 변형

김창대(Changdae Kim) 대한성서공회 2015 성경원문연구 Vol.- No.37

This study has attempted to elucidate the theological significance of Jeremiah’s new covenant with regard to the people in the Kingdom of God. The thesis is that the new covenant of Jeremiah seeks to make God’s people in the eschaton the ones that will actualize the ideal of the kingly priests as suggested in the Mosaic Covenant. In making a case for this, this study proposes that the new covenant has, among other theological meanings, the sense of consummating the kingdom of God by making God’s people kingly priests who practice justice and righteousness. In this attempt, our chief attention has been devoted to analyzing the text of Jeremiah 33:14-26 by using the method of textlinguistics. The hermeneutical method of textlinguistics is basically text-oriented in nature, with the assumption that the meanings of a text is embedded in the text when the author tries to convey his intentions to his reader (or audience) through the text. In this method, the intended meanings of a text are culled out from the view point of grammatical cohesion and semantic (or thematic) coherence. The method of textlinguistics also has its concern on how the author impacts the reader in such a way that the reader should respond to the intended meanings of the text. In this respect, a trend in this method focuses its attention on the structures of literary units through which the author arranges his emphases in order to facilitate the reader’s understanding of the communicative effects of the text. On the basis of the method of textlinguistics, this study pays its attention to the literary structure of Jeremiah 33:14-26, with the result of arguing that this unit forms a thematic peak in the context of Jeremiah 30-33. Furthermore, our textlinguistic analysis lends credence to the notion that the reference to Davidic descendants and Levites in this unit implies that in the kingdom of God, the people will be made kings and priests. In conclusion, from the above observations, it is clear that this way of making an exegesis of a text enhances our understanding of the unified relation between the Old and New Testaments from the perspective of the new covenant. The new covenant of the Old Testament connotes the making of God’s people into kingly priests, which is explicitly announced in the New Testament.

디젤산화촉매의 CO 활성 저하 원인 분석

김창대(Changdae Kim),권충일(Choongil Kwon),김석재(Seokjae Kim),여권구(Gwonkoo Yeo) 한국자동차공학회 2002 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2002 No.5_1

To meet future EURO-III, IV emission standards, it is essential to develop catalyst technology that will reduce diesel engine exhaust gases. In this study, deactivation of diesel oxidation catalyst used in fleet vehicle test was mainly investigated To conform the surface characterization of catalyst, BET, IC & CO chemisorption were used.<br/> The causes of deactivation of a diesel catalyst were several but the main factors were sulfur poisoning, carbon coking & Pt sintering among them. Therefore, the LOT of an endurance sample was increased higher than thai of a fresh Especially, the change of pore diameter & volume by sulfur was observed.

시편 1권의 문맥에서 본 시편 9-10편의 “아나브”(עָנָו)의 의미

김창대(Changdae Kim) 한국신학정보연구원 2020 Canon&Culture Vol.14 No.1

본 연구는 시편 9-10편에서 등장하는 “아나브”(עָנָו)의 의미가 시편 1권의 문맥에서 어떤 신학적 의미를 가지는 지를 살피는 데에 그 목적이 있다. 이를 위해 시편의 시들이 의도적으로 배열되었다는 구성적 방법을 사용하여, 시의 경계를 넘어 주위 시들의 문맥에서 עָנָו의 의미를 연구하였다. 구체적으로 9-10편의 문맥, 3-14편의 문맥, 더 나아가 시편 1권의 전체 문맥에서 이 단어가 어떤 신학적 의미를 가지는지에 초점을 맞췄다. 일차적으로 9-10편에서 “아나브”는 세상의 욕심을 멀리하고 인생의 연약함을 직시하여 하나님의 교제 속에서 하나님의 뜻인 공의와 의를 추구하는 자라는 신학적 의미를 가진다. 그래서 이런 자신의 정체성을 바탕으로 하나님을 의지하는 자로 제시된다. 다음으로 9-10편이 속해 있는 3-14의 문맥에서 이 단어의 의미는 더욱 확대되어, 하나님의 사랑을 체험하고, 자신도 하나님을 사랑하는 자의 모습을 갖는다(3-7편). 그리하여 하나님과 인격적 교제의 기쁨을 가지고 환난을 이기고자 하는 자임을 일깨워 준다(4:7, “주께서 내 마음에 두신 기쁨은”). 더 나아가 이 단어는 인생을 감찰하시는 하나님을 철저하게 신뢰하고 보호와 구원의 약속을 받는 축복의 사람이라는 이미지를 갖는다(11-14편) 다음으로 시편 1권의 문맥에서 이 단어의 신학적 의미를 관찰하면, 그 의미의 지평이 더욱 확장된다. 앞서 3-14편은 “아나브”가 하나님의 구원과 보호라는 복을 받을 것을 약속하였다. 그런데 15-24편은 그런 복을 시온의 복으로 병치시키고, 시온의 복을 받은 사람은 율법을 즐거워하여 율법을 묵상하는 자임을 밝히고 있다. 따라서 자연스럽게 “아나브”가 율법을 즐거워 하여 묵상하는 자라는 힌트를 준다. 이어 25-37편은 “아나브”가 언약과 도를 따라 땅 상속과 평강이라는 복을 받게 될 것을 강조한다(37:11, “온유한자는 땅을 차지하며 풍성한 화평으로 즐거워하리로다”). 끝으로 38-41편은 “아나브”가 고난을 통과하면서 자신이 죄인이며 아무것도 아닌 존재임을 깨닫고(38:4; 39:5-8), 율법을 즐거워하며 율법을 마음에 새기는 자임을 보여준다(40:8-9). 그리하여 “아나브”가 시편 1편이 복이 있는 자로 제시한 의인임을 깨닫게 해 준다(41:1). 결국 “아나브”는 고난 가운데서 인생의 덧없음과 자신이 아무것도 아님을 깨닫고, 하나님과의 교제의 기쁨 속에서 하나님을 의지하고 그분의 뜻을 자발적으로 행하고자 하여, 궁극적으로 참된 복을 받는 성도라고 정의할 수 있다. This work has its purpose in exploring the implications of the word עָנָו which occurs first in Psalms 9-10 throughout the entire Psalter. To this end, this study has used the compositional method in such a way of attending to the literary context surrounding Psalms 9-10 where the word is first mentioned. More specifically, in an effort to find the theological implications of עָנָו in the Psalms, our attention has been drawn to the context of Psalms 9-10, then to the context of Psalms 3-14, and finally to the broader context of Book I of the Psalter. In the process, the argument has been advanced that the word עָנָו in Psalms 9-10 has among other connotations the sense of pointing to a person who seeks the justice and righteousness of God in an intimate relationship with God, at the same time trusting in God. Within its immediate context of Psalms 3-14, the theological implications of the word עָנָו are further expanded in such a way that it includes the concept of a person who loves God in response to experiencing God’s love (Psalms 3-7). This leads to the notion that עָנָו implies also a person who overcomes any adversities with a joy coming from relationships with God. Furthermore, the contextual reading of Psalms 11-14 hints that עָנָו conveys the sense of a person who is blessed with the promise of salvation by God. Further observations of the implications of עָנָו within Book I of the Psalter, widen the horizons of our understanding of the theological implications of the word. In attending to the context of Psalms 15-24, the sense of עָנָו is revealed to embrace the concept of enjoying the law and meditating on it. From the contextual reading of the word in Psalms 25-37, it is evident that the identity of עָנָו is deeply related to a blessed person who is given the promises of God, that is to say, inheriting the earth as well as peace. Finally, when dealing with the implications of עָנָו in the context of Psalms 38-41, it is found that a picture of עָנָו is taken as a person who puts the law into his heart(40:8-9).

메모리 드리븐 컴퓨팅 연구 동향

김창대(Changdae Kim),고광원(Kwang-Won Koh),안백송(Baik Song An),차명훈(Myung Hoon Cha),김홍연(Hong Yeon Kim),이상민(Sang-Min Lee),김강호(Kang Ho Kim) 한국정보과학회 2019 정보과학회지 Vol.37 No.6

[디젤엔진부문] 승용차용 디젤엔진 촉매시스템 개발

김창대(Changdae Kim),김석재(Seokjae Kim),여권구(Gyunkoo Yeo),류명석(Myungseok Lyu) 한국자동차공학회 2000 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

To meet future U.S. & European NOx emission standards, it is essential to develop catalyst technology that will reduce NOx emission in addition to the other three pollutants(HC, CO, Paticulate). Two materials that attracted great attention as De-NOx catalysts are the ZSM-5 and BaO contained the commercial DOC. The manufactured several catalysts showed the NOx conversion of about 20-28% but the temperature window of those was narrow as 300~400°C. In case of a general diesel passenger car, engine outlet gas temperature is lower than 250°C under ECE mode. Finally, a new low temperature lean NOx catalyst will be described. In this paper, the possibility of the ZSM-5 and BaO contained the commercial DOC under diesel engine conditions as the 4-way catalyst was investigated