An Opportunity-based Age Replacement Policy with Warranty Analysed by Using TTT-Transforms

Iskandar, Bermawi P.,Klefsjo, Bengt,Sandoh, Hiroaki The Korean Reliability Society 2000 International Journal of Reliability and Applicati Vol.1 No.1

In a recent paper Iskandar & Sandoh (1999) studied an opportunity-based age replacement policy for a system which has a warranty period (0,S]. When the system fails at age x $\leq$ S a minimal repair is performed. If an opportunity occurs to the system at age x, S $\leq$ x $\leq$ T, we take the opportunity with probability p to preventively replace the system, while we conduct a corrective .replacement when its fails in (S,T). Finally, if its age reaches T, we perform a preventive replacement, Under this policy the design variable is T. For the case when opportunities occur according to a homogeneous Poisson process, the long-run average cost of this policy was formulated and studied analytically by Iskandar & Sandoh (1999). The same problem is here analysed by using a graphical technique based on scaled TTT-transforms. This technique gives, among other things, excellent possibilities for different types of sensitivity analysis. We also extend the discussion to the situation when we have to estimate T based on times to failure.

Investment Policy and Investment Opportunities of Uzbekistan

Iskandar Yuldashev 조선대학교 사회과학연구원 2008 서석사회과학논총 Vol.1 No.2

우즈베키스탄은 중앙아시아에서 인구가 가장 많은 국가로 경제 이행 전략과 그 결과가 상반되게 나타나는 흥미로운 특징을 가지고 있다. 오늘날 세계 경제 개발에서 해외직접투자 (FDI)는 중요한 요소로 자리 잡았다. 그리고 우즈베키스탄은 시장 경제로의 이행과정에서 국제투자시장의 대상이 되었다. 따라서 현재 우즈베키스탄의 투자 정책에서 국내외 자본 유치를 도모하는 것이 주요 특징이라 할 수 있다. 우즈베키스탄 경제 개발에서 이러한 투자유치가 결국 국가 경제의 원동력이 될 것이라는 판단 하에 우즈벡 정부는 투자 개발에 중요한 의미를 부여하고 있다. 본 연구는 우즈베키스탄의 현 투자 정책을 분석하는데 초점을 두면서 인센티브 정책의 존재와 투자 장벽 요인들 및 현 우즈벡 정부의 투자 유치정책에 대해 살펴보고자 한다. Uzbekistan is the most populated country in Central Asia which provides an interesting contrast in terms of the transition strategies and economic outcomes. The foreign direct investment has become an important feature of the development of the world economy. And Uzbekistan becomes a participant of international investments market in the process of market reforms. The stimulation of local and foreign private investments is the chief characteristic of the contemporary state investment policy of Uzbekistan. To the development of investment process in the country is assigned important role, since the investments are motive power in the development of national economy. This study aims at analyzing the investment policy of Uzbekistan, the presence of incentives and obstacles for investors as well as government policy for investment attraction has been brought into focus.

Hub Location-allocation in Computer-based Networks under Disruption Using Whale Optimization Algorithm

Iskandar MUDA,R. Sivaraman,Sulieman Ibraheem Shelash Al-Hawary,Untung Rahardja,Rusul S. Bader,Deni Kadarsyah,Karrar Shareef Mohsen,Abdullah Hasan Jabbar,Purnima Chaudhary 대한산업공학회 2022 Industrial Engineeering & Management Systems Vol.21 No.3

In this research, the location of hubs in computer networks is investigated using the whale optimization algorithm. The problem of locating hubs in computer networks is an optimization problem and requires the definition of a suitable fit function. Therefore, the total data transfer time and the cost of creating hubs is used as a fit function. Capacitive hubs increase network availability because hubs have more response capacity than the number of node requests connected to the hubs. In hub location issues, the study seeks to connect the nodes to the nearest hub and create a computer network with the least cost of connecting the nodes to the hubs. The present study attempts to reduce disruptions in computer networks as a research innovation. Therefore, by using the whale optimization algorithm and solving the model with its help, the effective factors that affect computer network disruptions and examining the effect of each are identified. Given the results, the model’s reaction in terms of time and cost led to an increase in temporal and cost parameters.

Growth Optimization of Thraustochytrid Strain 12B for the Commercial Production of Docosahexaenoic Acid

Ahmad Iskandar Bin Haji Mohd Taha,Takashi Kimoto,Teruyuki Kanada,Hidetoshi Okuyama 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.suppl1

High yield of cell, lipid, and docosahexaenoic acid (DHA) from thraustochytrid strain 12B were achieved without the use of a complex medium and at low NaCl concentration which is detrimental to avoid unnecessary corrosion of steel tank equipment during cultivation. Culture medium that contained only 0.1% NaCl and 1%MgSO4 in an organic base solution containing 8% glucose,1% yeast extract, and 1% peptone, referred here as NM medium, was found to be as good as or superior to the culture medium prepared from 50%(v/v) seawater with percentage lipid/dry cell weight (DCW) of 66.4%(w/w)and DHA yield up to 43.95 mg/g DCW for the thraustochytrid strain 12B. The NM medium was also applicable to the prominently high DHA-accumulating Schizochytrium limacinum SR21, and therefore this medium could probably be used for other thraustochytrid and other types of microbial strains as well.

La Niña Modoki Enhanced Summer-Autumn Precipitation over the Indonesian Region

Iskhaq Iskandar,Deni Okta Lestari,Yukio Masumoto 한국기상학회 2022 Asia-Pacific Journal of Atmospheric Sciences Vol.58 No.4

Possible impacts of the La Niña and La Niña Modoki on the precipitation over the Indonesian region were investigated in thisstudy. The analysis used monthly precipitation, sea surface temperature (SST), and pressure level wind for a period January1948 to December 2013. The results clearly show the change in the distribution of precipitation associated with the La NiñaModoki event. The results show a remarkable different impact of those two flavors of La Niña event on the precipitation overthe Indonesian region. During the boreal summer season in June-July-August (JJA) to boreal autumn season in September-October-November (SON), the La Niña Modoki caused a significant increase of precipitation almost all over the Indonesianregion, in particular over the Kalimantan, Sulawesi, Papua, and central to northern parts of Sumatra Islands. The conditioncontinued to the boreal winter season (December-January-February; DJF), although the affected regions were narrowercompared to those during previous two seasons. The enhanced precipitation was related to warmer SST anomalies in thesurrounding sea of the Indonesian region that triggered low-level wind convergence, and increased ascending convectivebranch of the Walker Circulation leading to enhanced atmospheric convection over the Indonesian region.

Why was the 2008 Indian Ocean Dipole a Short-lived Event?

Iskhaq Iskandar,Muhammad Irfan,Fadli Saymsuddin 한국해양과학기술원 2013 Ocean science journal Vol.48 No.2

In this paper, the role of equatorial oceanic waves in affecting the evolution of the 2008 positive Indian Ocean Dipole (IOD) event was evaluated using available observations and output from a quasi-analytical linear wave model. It was found that the 2008 positive IOD was an early matured and abruptly terminated event: developed in April, matured in July, and diminished in September. During the development and the maturation of the 2008 positive IOD event, the wind-forced Rossby waves played a dominant role in generating zonal current anomalies in the western equatorial Indian Ocean, while a complex interplay between the wind-forced upwelling Kelvin waves and the eastern-boundary-generated Rossby waves accounted for most of the variability in the eastern basin. The latter induced eastward zonal current anomalies near the eastern boundary during the peak phase of the event. The 2008 positive IOD event was abruptly terminated in mid-July. We found that there were strong eastward zonal currents in mid-July, though the surface wind anomalies in the eastern basin continued to be westward (upwelling favorable). Our analysis shows that these eastward zonal currents mainly resulted from the easternboundary-generated upwelling Rossby waves, although the contribution from the wind-forced downwelling Kelvin waves was not negligible. These eastward zonal currents terminated the zonal heat advection and provided a favorable condition for surface heat flux to warm the eastern basin.

The Journalism Crisis in the Era of the COVID-19 Pandemic in Indonesia

Dudi Iskandar,Deddy Mulyana,Sitti Murni Kaddi World Association for Triple Helix and Future Stra 2023 Journal of Contemporary Eastern Asia Vol.22 No.2

The focus of this research is the practice of journalism in relation to the Behavioural Change Journalism Fellowship (JFPP) during the COVID-19 pandemic in Indonesia. Journalists and curators who are participants in the Behavioural Change Journalism Fellowship received fundings from the state. The Behavioural Change Journalism Fellowship is a unique model because it is the only one in the world in journalism practice that involves state's financial assistance during the COVID-19 pandemic. These fundings from the state for the media lead to dilemmas and controversies. This research uses a qualitative approach and a single holistic case study method. The Behavioural Change Journalism Fellowship was held from May to December 2021, involving 7,276 journalists from 857 media (print, television, radio, and online media) and 26 curators. This study found that during the Behavioural Change Journalism Fellowship, journalism experienced a crisis and lost its function as a control overpower. Giving cash to journalists and curators during the fellowship makes journalism lose its independence and objectivity. The Behavioural Change Journalism Fellowship has degraded or eliminated the function of the press as a watchdog. Incentives for journalists while participating in the Behavioural Change Journalism Fellowship is a long-term investment by the government to co-opt Indonesian media and journalists in the future. On the other hand, the Behavioural Change Journalism Fellowship raises another aspect; the crisis of journalism. Journalism work produced in the Behavioural Change Journalism Fellowship does not reflect the values and principles of journalism. Journalism values, such as independence and impartiality, are absent from the Behavioural Change Journalism Fellowship product.

Tuberculosis Cutis Orificialis in Adalimumab Related Immunosupressive Patient

( Mehdi Iskandarli ),( Bengu Gerceker Turk ),( Banu Yaman ),( Naim Ceylan ),( Can Ceylan ) 대한피부과학회 2017 Annals of Dermatology Vol.29 No.1

An Opportunity-based Age Replacement Policy with Warranty Analysed by Using TTT-Transforms

Bermawi P. Iskandar,Bengt klefsjo,Hiroaki Sandoh 한국신뢰성학회 2000 International Journal of Reliability and Applicati Vol.1 No.1

A Proposed System Architecture of IoT-Assisted Educational Tools for Hybrid Learning

Thian Celine Iskandar 국제과학영재학회 2022 APEC Youth Scientist Journal Vol.14 No.1

In recent years, the education sector has been one of the hardest hit by the COVID-19 pandemic, with schools struggling to find ways to stay open. A lot of educational institutions choose to implement hybrid learning systems, which is the combination of face-to-face and online learning using a variety of e-learning tools. Some educational tools are required to support the interactions between students, lecturers, and administrators so that the teaching and learning process runs smoothly. As an emerging e-learning system, there are some challenges that arise related to the tools. Also, constant technical issues faced by both teachers and students on these e-learning tools often require technical support to rectify, causing frequent disruptions in the learning flow. In this study, we analyzed the limitations and challenges of the existing e-learning tools that support the hybrid learning system at Sekolah Menengah Atas Kristen Penabur. This study proposes a solution for solving the present issues and limitations of the current e-learning tools. We propose an efficient architecture that supports efficient and reliable e-learning tools for students, lecturers, and administrators at SMAK Penabur. According to the findings, the proposed architecture has a significant impact on the learning and teaching development of hybrid learning environments. It also provides an efficient and reliable means of using e-learning tools in a hybrid learning environment.