Emperor Penguins’ Behavior-based Virtual Machine Placement Algorithm for avoiding heat islands in Cloud Computing Environment

최정열 한국차세대컴퓨팅학회 2018 한국차세대컴퓨팅학회 논문지 Vol.14 No.2

In cloud computing environment, a single server accommodates multiple virtual machines for resource efficiency. It is necessary to place virtual machines on servers according to the energy and resource efficient policy. This paper proposes a virtual machine placement (VMP) algorithm based on the emperor penguins’ behavior, which attempts to minimize loss of penguins’ body temperature. Penguins with the greatest heat loss continuously move in their group against strong external winds. The proposed algorithm attempts to place virtual machines on servers for minimizing power consumption, and periodically migrate virtual machines on the server, which possibly occurs a heat island, to a server with low temperature. This paper proposes server-based and rack-based VMP algorithms. Simulation results show that the two proposed algorithms consumed server power similar to the existing algorithm while virtual machines were placed in a mostly distributed way. In case of applying the rack-based VMP, the difference in power consumption among servers is the smallest so that this algorithm is considered to be the most suitable for preventing the heat island.

신축성 전자패키징을 위한 CNT-Ag 복합패드에서의 플립칩 공정

최정열,오태성,Choi, Jung Yeol,Oh, Tae Sung 한국마이크로전자및패키징학회 2013 마이크로전자 및 패키징학회지 Vol.20 No.4

As a basic research to develop stretchable electronic packaging technology, CNT-Ag composite pads were formed on top of Cu/Sn chip bumps and flip-chip bonded using anisotropic conductive adhesive. Average contact resistances of the flip-chip joints were measured with respect to bonding pressure and presence of the CNT-Ag composite pads. When Cu/Sn chip bumps with CNT-Ag composite pads were flip-chip bonded to substrate Cu pads at 25MPa or 50 MPa, contact resistance was too high to measure. The specimen processed by flip-chip bonding the Cu/Sn chip bumps with CNT-Ag composite pads to the substrate Cu pads exhibited an average contact resistance of $213m{\Omega}$. On the other hand, the flip-chip specimens processed by bonding Cu/Sn chip bumps without CNT-Ag composite pads to substrate Cu pads at 25MPa, 50MPa, and 100MPa exhibited average contact resistances of $370m{\Omega}$, $372m{\Omega}$, and $112m{\Omega}$, respectively. 신축성 전자패키징 기술개발을 위한 기초연구로서 Cu/Sn 범프에 CNT-Ag 복합패드를 형성한 칩을 이방성 전도접착제를 사용하여 플립칩 본딩한 후, CNT-Ag 복합패드의 유무 및 본딩압력에 따른 플립칩 접속부의 접속저항을 측정하였다. CNT-Ag 복합패드가 형성된 Cu/Sn 칩 범프를 25MPa과 50MPa의 본딩압력으로 플립칩 본딩한 시편들은 접속저항이 너무 높아 측정이 안되었으며, 100MPa의 본딩압력으로 플립칩 본딩한 시편은 $213m{\Omega}$의 평균 접속저항을 나타내었다. 이에 비해 CNT-Ag 복합패드가 없는 Cu/Sn 칩 범프를 사용하여 25MPa, 50 MPa 및 100 MPa의 본딩압력으로 플립칩 본딩한 시편은 각기 $1370m{\Omega}$, $372m{\Omega}$ 및 $112m{\Omega}$의 평균 접속저항을 나타내었다.

The Limitations on the Use of Big Data Pursuant to Data Privacy Regulations in Korea

최정열,손도일,김세진 서울대학교 아시아태평양법연구소 2017 Journal of Korean Law Vol.17 No.1

This study provides an overview of the current big data industry and regulatory parameters in Korea. It also makes policy and legislative recommendations for stimulating the big data industry, while preserving a balance between industry growth and the privacy of data subjects. For this purpose, we begin by reviewing privacy legislations from the European Union, the United States, and Japan. We also present domestic and overseas data breach cases. Further, we study relevant Korean court precedents and Korean privacy legislations to pinpoint obstacles to the promotion of big data under the current legislative regime. South Korea’s thorough privacy protection regulations essentially rival those of Europe. As of 2017, key privacy policy legislations applicable in Korea are given under the Personal Information Protection Act, the Act on Promotion of Information and Communications Network Utilisation and Information Protection, etc., and the Act on the Use and Protection of Credit Information, etc. Because Korean privacy legislations define “identifiability” vaguely, businesses that employ big data technology face uncertainty about how to comply with various statutes and regulations, and this uncertainty restricts their production and use of big data. Korean privacy legislations generally require personal information processors to acquire opt-in consents from data subjects to collect, use, and give third parties personal information. As a result, acquiring advance opt-in consents is necessary to generate big data from information that contains personal information. Legislative direction that stimulates the big data industry must strike a fine balance between the constitutional rights to privacy and consumers’ rights (i.e., the data subject of collected personal information) and the property rights of companies that own such information (i.e., big data companies). On the one hand, legislative changes extracting one-sided concessions from individuals about their privacy will likely be met with public resistance. On the other hand, continuing with laws that hamper the growth of the big data industry will undoubtedly sideline Korea from the fourth industrial revolution. Hence, scholars, legislators, and legal professionals must explore comprehensive measures that reconcile these two perspectives.

도시철도 침목플로팅궤도(STEDEF)의 침목방진패드 피로거동 분석

최정열,이정숙,봉재근,김수진,정지승 국제문화기술진흥원 2020 The Journal of the Convergence on Culture Technolo Vol.6 No.3

본 연구는 현장측정결과를 바탕으로 도시철도 침목플로팅궤도(STEDEF)에 사용되는 침목방진패드의 스프링강성 변화율에 따른 궤도충격계수 변화수준의 경향성을 분석하고, 측정결과와 700만회 피로시험결과의 상관관계를 입증하였다. 또한 STEDEF 궤도구조에 사용되는 침목방진패드의 비선형 피로거동특성이 고려된 침목방진패드의 피로영향선도를 제시하였다. 현장측정결과를 바탕으로 분석한 궤도충격계수-궤도지지강성 선도의 침목방진패드 스프링강성 변화율 30% 이상에 대한 궤도충격계수의 비선형 특성이 피로시험결과와 일치하는 것으로 분석되었다. In this study, the variation of track impact factor according to the spring stiffness change rate of sleeper resilience pad was analyzed based on field measurements. In addition, the correlation between field measurement results and 7 million fatigue test results was verified. The fatigue effect diagram of the sleeper resilience pads was presented considering the nonlinear deterioration characteristics of the sleeper resilience pads used for the STEDEF track. Based on the field measurement results, the nonlinear characteristics of the track impact factor for the spring stiffness change rate over 30% of sleeper resilience pad on the track impact factor-track support stiffness diagram were analyzed to be consistent with the fatigue test results.

한국의 외식프랜차이즈 임대 소규모 상가의 적정 임대료 연구

최정열,박태진 한일경상학회 2021 韓日經商論集 Vol.93 No.-

Purpose: The current rent payment structure only serves as a contract rent that does not take into account the tenant’s profits of the franchisee. Therefore, this study studies the appropriate value of tenants and lords as the operators of different businesses in the space of small commercial real estate. Research design, data, and methodology: In the case of the same franchise brand, the profit and loss structure of sales and franchisees differs depending on the region and the commercial area. Therefore, it is necessary to set the appropriate rent considering the profit and loss of the franchisee rather than judging the outward sales of the franchise as a measure of rent evaluation. So, to calculate the the appropriate rent, The wage income of each region was selected as a variable representing the expected income of the franchisee, and the weighted index was given to the difference, and the appropriate rent was calculated by adding the current rent. Results: If the appropriate rent By Region and industry is low in the proportion of negative (-), or has a positive (+) value, it is the case where the profit and loss of the franchisee business is good in the area. In these cases, the lords may consider rent increases, and it is necessary to focus on income returns separately from capital returns. Implications: The profit and loss level of franchisees By Region and industry derived from this study can be the business indicators of franchisees. The appropriate rent will be useful information that can be used for investors toimplement win-win rental strategies or to refer to rent negotiations in relation to key franchise stores, even before investment or during the lease operation period.

콘크리트궤도의 궤도지지강성 평가시스템에 관한 연구

최정열,김만화,김현수,정지승 국제문화기술진흥원 2020 The Journal of the Convergence on Culture Technolo Vol.6 No.2

현행 탄성 재료 교체 및 성능평가는 작업성 및 작업공정이 매우 복잡하고 시간도 많이 소요됨은 물론 탄성 재료의 교체시기를 사전에 파악하기 어려운 반면, 본 연구에서 제시한 방법은 탄성 재료의 궤도지지강성 변화율을 상품 한계치와 기능 한계치를 비교 표시해 줌으로써 탄성 재료 교체의 필요성 및 교체 전, 후의 궤도지지강성 개선효과를 현장에서 즉각적으로 실험데이터를 바탕으로 입증이 가능하다. 또한 궤도지지강성 평가 소프트웨어를 이용하여 현장시험을 통해 획득한 탄성 재료에 대한 성능평가 데이터가 관리자 컴퓨터에 통합 관리되기 때문에 탄성재료의 교체시기 및 위치를 파악함으로써 교체 계획 수립 및 유지관리 이력 관리가 가능하다. 따라서 선로 순회하는 작업시간 동안 다수의 측점에서 탄성재료의 성능 및 상태를 현재 운영상태에서 궤도성능(궤도지지강성) 및 궤도재료의 내구성능(노후화 수준, 물성변화율 등)을 평가함으로써 시기적절하게 탄성재료를 교체할 수 있으며, 지속적으로 탄성재료의 성능변화(열화) 상태를 모니터링 할 수 있어 궤도유지관리에 활용도가 높을 것으로 판단된다. A conventional elastic material replacement and performance evaluation are very complicated and time-consuming, and it is difficult to know when to replace the elastic material in advance. By comparing with the product limit and the functional limit, the necessity of elastic material replacement and the improvement of track support stiffness according to replacement can be immediately demonstrated based on experimental data. Using an evaluation system of track support stiffness, the performance evaluation data for elastic materials obtained through field tests using software for track support stiffness is integrated and managed on the administrator's computer. Therefore, the replacement plan is established and maintenance history is managed by identifying the replacement time and location of elastic materials. It is possible to evaluate the performance and condition of the elastic material at the various points during the working time of the track inspection and the track performance (track support stiffness) and durability of the elastic material (aging level, spring stiffness variation rate, etc.) at the operation condition. The elastic material could be replaced timely, and the deterioration of the elastic material can be continuously monitored.

기계학습 활용을 위한 학습 데이터세트 구축 표준화 방안에 관한 연구

최정열 한국디지털정책학회 2018 디지털융복합연구 Vol.16 No.10

EP가 적용된 마찰 진자형 지진격리받침의 피로거동분석

최정열,박희수,정지승 국제문화기술진흥원 2020 The Journal of the Convergence on Culture Technolo Vol.6 No.4

As the risk of earthquakes increases recently, earthquake-resistant designs were getting interest. For this reason, this study applies that Friction pendulum-type seismic isolator is a device that attenuates seismic energy by friction and pendulum motion. The friction pendulum-type seismic isolator of this study is very easy to transport, install and maintain with light weight of metal by applying the slider using high strength engineering plastic. In addition, there is an advantage that the corrosion resistance is very excellent compared to the existing metal parts. However, there is concern about long-term durability by replacing metal materials. In this study, the frictional pendulum-type seismic isolator with EP was applied to compressive-shear test, repeated fatigue test, and ultimate load test after fatigue test, and analyzed the deformation and shear or properties after the test. As the results, the adequacy of long term fatigue durability was experimentally proven. 최근 지진에 대한 위험이 고취됨에 따라 내진설계에 대한 관심이 높아지고 있는 실정이다. 이에 본 연구에서는면진장치중 하나인 마찰 진자형 지진격리받침을 고강도 엔지니어링 플라스틱을 이용하여 슬라이더(spherical)를 적용하였다. 이는 다른 금속에 비해 가벼운 중량으로 운반, 설치 및 유지보수가 매우 용이하고, 기존의 금속부품 대비 내부식성이 매우 우수하다. 또한 특수 마찰재를 삽입하여 사용하므로 교체가 용이하여 마찰계수 조절이 가능하다는 장점을 입증하였지만 금속 소재 슬라이더 대비 장기 처짐에 대한 우려가 대두되어 왔다. 따라서 본 연구에서는 개발된마찰 진자형 지진격리받침으로 압축-전단시험, 반복피로시험 후 극한하중 재하시험을 실시하여 시험 후의 압축 및 전단특성 변화와 반복피로시험 후 극한하중 재하시 슬라이더의 변형 및 전단특성을 측정, 분석하여 슬라이더의 장기 처짐값을 측정하였고 그 처짐값이 사용 설계 허용범위 내에 있는지를 입증하였다.

도시철도 침목플로팅궤도 궤도구성품의 손상평가

최정열,김학선,한경성,장철주,정지승 국제문화기술진흥원 2019 The Journal of the Convergence on Culture Technolo Vol.5 No.4

In this study, in order to evaluate the damage and deterioration of the track components of sleeper floating track (STEDEF), the field samples(specimens) were taken from the serviced line over 20 years old, and the track components were visually inspected, and investigated by laboratory tests and finite element analysis. As a result of visual inspection, the damage of the rail pad and fastener was slight, but the rubber boot was worn and torn at the edges of bottom. The resilience pads were clearly examined for thickness reduction and fatigue hardening layer. As a result of spring stiffness test of rail pad and resilience pad, the deterioration of rail pad was insignificant, but the deterioration of resilience pad exceeded design standard value. Therefore resilience pad was directly affected by train passing tonnage. As a result of comparing the deterioration state of the field sample and the numerical analysis result, the stress and displacement concentration position of the finite element model and the damage position of the field sample were coincident. 본 연구에서는 도시철도 침목플로팅궤도(STEDEF) 궤도구성품의 손상영향을 분석하기 위하여 사용연수가 20년 이상 경과된 현장에서 시료를 채취하여 궤도재료에 대한 육안검사와 실내시험 및 유한요소해석을 통해 궤도구성품의 손상취약부를 분석하였다. 육안검사결과 레일패드와 체결구는 특이사항이 없었으나 침목방진상자는 모서리부분의 마모 및 찢어지는 현상이 발생하였다. 침목방진패드는 두께감소 및 피로경화층이 뚜렷하게 조사되었다. 레일패드와 침목방진패드에 대한 스프링강성 시험결과, 레일패드의 노후는 뚜렷하지 않았으나 침목방진패드는 설계기준치를 크게 상회하는 것으로 나타나 침목방진패드는 통과톤수에 직접적인 영향을 받는 것으로 분석되었다. 현장시료의 열화상태와 수치해석 결과와의 비교결과, 수치해석모델의 응력 및 변위 집중위치와 현장시료의 손상위치가 일치하는 것으로 나타나 공용중인 침목플로팅궤도 궤도구성품의 손상취약부를 실험 및 해석적으로 입증하였다.

IEEE 802.16m에서 패킷 도착 정보를 고려한 적응형 수면 사이클 조절 알고리즘

최정열 한국차세대컴퓨팅학회 2012 한국차세대컴퓨팅학회 논문지 Vol.8 No.4

본 논문은 4세대 무선 이동 통신 기술 중의 하나인 IEEE 802.16m의 효율적인 에너지 관리를 위한 전력 절감 방안을 기술한다. 배터리로 구동되는 이동 단말은 특히 효율적인 에너지 관리가 중요한데, 사용자가 서비스를 사용하지 않는 기간 동안에 수면 모드로 동작케 함으로써 전력 절감을 시도한다. 본 논문에서는 이동 단말에서 패킷의 도착 정보를 이용하여 수면 사이클을 동적으로 조절케 함으로써 에너지 절감은 물론 서비스 대기 지연 시간도 효율적으로 관리할 수 있는 알고리즘을 제안한다. 제안한 알고리즘의 성능을 에너지 소비 측면과 서비스 지연 시간 측면에서 컴퓨터 시뮬레이션을 통하여 분석한다. 그리고, HTTP와 FTP와 같은 응용 서비스를 사용하고 있는 상황에서의 제안한 알고리즘의 효과를 제시한다.