International Journal of Sustainable Lighting <p><strong>Introduction</strong></p> <p>The International Journal of Sustainable Lighting (IJSL) is the successor of the former Ingineria Iluminatului - Journal of Lighting Engineering, issued in Romania starting with 1999. IJSL aims to become an internationally recognized journal and to complement the existing prestigious lighting journals with an emphasis on emerging lighting issues including light pollution, chronobiology, sustainable buildings by extending its readers and authors to the worldwide lighting communities. The IJSL is an open access journal and is published bi-annaully in June, and December each year.</p> <p><strong>Aims and Scope</strong></p> <p>The International Journal of Sustainable Lighting is based on a change of paradigm from energy-efficiency to trans-disciplinarity (including energy, ecology, biology, green buildings, astronomy); it is a peer reviewed scientific journal encompassing experimental, theoretical and applied research results with respect to field of sustainable lighting. It provides a forum for architects, engineers, biologists and researchers involved in the design, operation, construction and utilization of lighting.</p> <p>The foremost objective is to give a quality online publication to our readers and authors. In this pursuit, our effort focuses upon quality publishing and an unquestioned commitment to the highest standards of professional and corporate ethics.</p> <p><strong>Editors-in-Chief</strong></p> <p>Jeong Tai Kim, Professor, Kyung Hee University, Republic of Korea</p> <p>Dorin Beu, Professor, Technical University of Cluj-Napoca, Romania</p> <p><strong>Executive Editor</strong></p> <p>Geun Young Yun, Associate Professor, Kyung Hee University, Republic of Korea</p> <p>&nbsp;</p> <p>&nbsp;</p> International Journal of Sustainable Lighting en-US International Journal of Sustainable Lighting 2586-1247 <p>All International Journal of Sustainable Lighting (IJSL) content is Open Access, meaning it is accessible online without fee under the terms of the Creative Commons Attribution License ( &nbsp;For any reuse, redistribution, or reproduction of a work, users must clarify the license terms under which the work was produced. Neither the text itself nor the ideas presented in it may be used for commercial purposes.</p> The effect of age on white light perception. <p>The way that persons from different age groups experience “white light” is investigated. Human eye lens transmission changes spectrally with age and this may influence the way that humans from different ages experiences light. Such a difference may be important in industrial and medical environments. Two different age groups, one group younger than 40 years of age and another group older than 50 years of age were subjected to the same “white” definition task. A conventional single-booth setup was used where observers were able to adjust the intensity of four coloured LED’s. Results of the psychophysical test procedure were used to generate specifications of two light sources, as selected by the two age groups. The two age groups selected two very different light sources when tasked to achieve a “perception” of white. Results show that the older group prefers a source with a colour rendering index number of 89 and the younger group prefers a source with a colour rendering index number of 74. The sources selected by the two age groups specifies correlated colour temperature values of 5150 K for the older age group and 6592 K for the younger group.</p> Jacobus Gideon van der Westhuyzen Frederick Wilhelm Leuschner Copyright (c) 2018 Jacobus Gideon van der Westhuyzen, Frederick Wilhelm Leuschner 2018-10-24 2018-10-24 20 2 29 43 10.26607/ijsl.v20i2.83 Discomfort Glare Evaluation using DIALux Lighting Simulation software and using developed Python Program model <p>Glare is a visual sensation caused by excessive brightness. It is subjective and person dependent. So, it is very difficult to measure glare factor accurately. Glare can be disabling or uncomfortable.&nbsp; Disability glare is the reduction in vision caused by bright light sources and it can be increased with the age of a person. Discomfort glare is a sensation of irritation due to bright light sources. There are various methods to evaluate discomfort glare. These methods are discussed in this paper.</p> <p>This paper mainly focuses on two methods of discomfort glare evaluation; Unified Glare Rating (UGR) and Daylight Glare Probability (DGP). These glare factors are calculated by using DIALux lighting simulation software and by using developed program. The experimentation was carried out in two different spaces; Conference room and Optoelectronics laboratory. The values of UGR, daylight factor are calculated by using DIALux and developed program. The comparison of the results obtained is discussed at the end of this paper.</p> Jayashri Aniket Bangali Copyright (c) 2018 Jayashri Aniket Bangali 2018-10-24 2018-10-24 20 2 44 50 10.26607/ijsl.v20i2.85 Photons without borders: quantifying light pollution transfer between territories <p>The light pollution levels experienced at any given site generally depend on a wide number of artificial light sources distributed throughout the surrounding territory. Since photons can travel long distances before being scattered by the atmosphere, any effective proposal for reducing local light pollution levels needs an accurate assessment of the relative weight of all intervening light sources, including those located tens or even hundreds of km away. In this paper we describe several ways of quantifying and visualizing these relative weights. Particular emphasis is made on the aggregate contribution of the municipalities, which are -in many regions of the world- the administrative bodies primarily responsible for the planning and maintenance of public outdoor lighting systems</p> Salvador Bará Raul C. Lima Copyright (c) 2018 Salvador Bará, Raul C. Lima 2018-10-24 2018-10-24 20 2 51 61 10.26607/ijsl.v20i2.87 Contentious Light: An Analytical Framework for Lighting Conflicts <p>This paper takes into view the broad range of contemporary conflicts regarding outdoor lighting. It proposes a working-definition that allows for differentiating lighting conflicts from other forms of lighting-related contention, as well as an analytical framework that allows for the structured description of individual lighting conflicts, and the comparative analysis of multiple cases. The analytical framework was developed based on the social-scientific analysis of media reports of existing conflict cases in Europe and North America, and informed by existing knowledge from the fields of lighting and conflict studies. A central challenge for developing such a framework is dealing with the high level of contingency and complexity of lighting conflicts. The framework reduces this complexity by focusing its field of vision to those aspects that are directly related to the lighting and its contestation. For each of these aspects, it provides sets of descriptive variables that allow for describing the conflicts’ individuality in a standardized – and thus comparable – way. The framework strictly separates the regarded aspects from their judgment by the conflict parties, making it possible to contrast their views on one and the same lighting situation. A visual template supports the process of analysis. It allows for depicting individual cases in short, and for clearly identifying where perspectives differ. At the multiple-case level, the framework not only opens up possibilities for spatial and temporal comparisons of lighting conflicts and the subsequent development of typologies, but also for harnessing their potential for informing the development of more sustainable planning and policy approaches for artificial lighting.</p> Josiane Maria Meier Copyright (c) 2018 Josiane Maria Meier 2019-02-04 2019-02-04 20 2 62 77 10.26607/ijsl.v20i2.89