| 1 | 
  | 
<html> | 
| 2 | 
+ | 
<!-- RCSid $Id$ --> | 
| 3 | 
  | 
<head> | 
| 4 | 
  | 
<title> | 
| 5 | 
< | 
The RADIANCE 4.1 Synthetic Imaging System | 
| 5 | 
> | 
The RADIANCE 5.3 Synthetic Imaging System | 
| 6 | 
  | 
</title> | 
| 7 | 
  | 
</head> | 
| 8 | 
  | 
<body> | 
| 10 | 
  | 
<p> | 
| 11 | 
  | 
 | 
| 12 | 
  | 
<h1> | 
| 13 | 
< | 
The RADIANCE 4.1 Synthetic Imaging System | 
| 13 | 
> | 
The RADIANCE 5.3 Synthetic Imaging System | 
| 14 | 
  | 
</h1> | 
| 15 | 
  | 
 | 
| 16 | 
  | 
<p> | 
| 798 | 
  | 
 | 
| 799 | 
  | 
<dd> | 
| 800 | 
  | 
        Trans2 is the anisotropic version of <a HREF="#Trans">trans</a>.   | 
| 801 | 
< | 
        The string arguments  are  the same as for plastic2, and the real arguments are the same as  for  trans  but  with  an  additional roughness value. | 
| 801 | 
> | 
        The string arguments  are  the same as for <a HREF="#Plastic2">plastic2</a>, | 
| 802 | 
> | 
        and the real arguments are the same as  for  trans  but  with  an  additional roughness value. | 
| 803 | 
  | 
 | 
| 804 | 
  | 
<pre> | 
| 805 | 
  | 
        mod trans2 id | 
| 811 | 
  | 
<p> | 
| 812 | 
  | 
 | 
| 813 | 
  | 
<dt> | 
| 814 | 
+ | 
        <a NAME="Ashik2"> | 
| 815 | 
+ | 
        <b>Ashik2</b> | 
| 816 | 
+ | 
        </a> | 
| 817 | 
+ | 
 | 
| 818 | 
+ | 
<dd> | 
| 819 | 
+ | 
        Ashik2 is the anisotropic reflectance model by Ashikhmin & Shirley. | 
| 820 | 
+ | 
        The string arguments are the same as for <a HREF="#Plastic2">plastic2</a>, but the real | 
| 821 | 
+ | 
        arguments have additional flexibility to specify the specular color. | 
| 822 | 
+ | 
        Also, rather than roughness, specular power is used, which has no | 
| 823 | 
+ | 
        physical meaning other than larger numbers are equivalent to a smoother | 
| 824 | 
+ | 
        surface. | 
| 825 | 
+ | 
<pre> | 
| 826 | 
+ | 
        mod ashik2 id | 
| 827 | 
+ | 
        4+ ux uy uz funcfile transform | 
| 828 | 
+ | 
        0 | 
| 829 | 
+ | 
        8 dred dgrn dblu sred sgrn sblu u-power v-power | 
| 830 | 
+ | 
</pre> | 
| 831 | 
+ | 
 | 
| 832 | 
+ | 
<p> | 
| 833 | 
+ | 
 | 
| 834 | 
+ | 
<dt> | 
| 835 | 
  | 
        <a NAME="Dielectric"> | 
| 836 | 
  | 
        <b>Dielectric</b> | 
| 837 | 
  | 
        </a> | 
| 1154 | 
  | 
<p> | 
| 1155 | 
  | 
 | 
| 1156 | 
  | 
<dt> | 
| 1157 | 
+ | 
        <a NAME="aBSDF"> | 
| 1158 | 
+ | 
        <b>aBSDF</b> | 
| 1159 | 
+ | 
        </a> | 
| 1160 | 
+ | 
 | 
| 1161 | 
+ | 
<dd> | 
| 1162 | 
+ | 
        The aBSDF material is identical to the BSDF type with two | 
| 1163 | 
+ | 
        important differences.  First, proxy geometry is not | 
| 1164 | 
+ | 
        supported, so there is no thickness parameter.  Second, an | 
| 1165 | 
+ | 
        aBSDF is assumed to have some specular through component | 
| 1166 | 
+ | 
        (the ’a’ stands for "aperture"), | 
| 1167 | 
+ | 
        which is treated specially during the direct calculation | 
| 1168 | 
+ | 
        and when viewing the material.  Based on the BSDF data, the | 
| 1169 | 
+ | 
        coefficient of specular transmission is determined and used | 
| 1170 | 
+ | 
        for modifying unscattered shadow and view rays. | 
| 1171 | 
+ | 
 | 
| 1172 | 
+ | 
<pre> | 
| 1173 | 
+ | 
        mod aBSDF id | 
| 1174 | 
+ | 
        5+ BSDFfile ux uy uz funcfile transform | 
| 1175 | 
+ | 
        0 | 
| 1176 | 
+ | 
        0|3|6|9 | 
| 1177 | 
+ | 
             rfdif gfdif bfdif | 
| 1178 | 
+ | 
             rbdif gbdif bbdif | 
| 1179 | 
+ | 
             rtdif gtdif btdif | 
| 1180 | 
+ | 
</pre> | 
| 1181 | 
+ | 
 | 
| 1182 | 
+ | 
<p> | 
| 1183 | 
+ | 
        If a material has no specular transmitted component, it is | 
| 1184 | 
+ | 
        much better to use the BSDF type with a zero thickness | 
| 1185 | 
+ | 
        than to use aBSDF. | 
| 1186 | 
+ | 
<p> | 
| 1187 | 
+ | 
 | 
| 1188 | 
+ | 
<dt> | 
| 1189 | 
  | 
        <a NAME="Antimatter"> | 
| 1190 | 
  | 
        <b>Antimatter</b> | 
| 1191 | 
  | 
        </a> | 
| 1469 | 
  | 
</h4> | 
| 1470 | 
  | 
 | 
| 1471 | 
  | 
A mixture is a blend of one or more materials or textures and patterns. | 
| 1472 | 
+ | 
Blended materials should not be light source types or virtual source types. | 
| 1473 | 
  | 
The basic types are given below. | 
| 1474 | 
  | 
 | 
| 1475 | 
  | 
<p> | 
| 1542 | 
  | 
        arguments, the red, green and blue values | 
| 1543 | 
  | 
        corresponding to the pixel at (u,v). | 
| 1544 | 
  | 
 | 
| 1489 | 
– | 
</dl> | 
| 1545 | 
  | 
<p> | 
| 1546 | 
  | 
 | 
| 1547 | 
  | 
<dt> | 
| 1843 | 
  | 
or converted a standard image format using one of the following | 
| 1844 | 
  | 
<b>translators</b>: | 
| 1845 | 
  | 
        <ul> | 
| 1846 | 
< | 
        <li> <b>Ra_avs</b> | 
| 1847 | 
< | 
                converts to and from AVS image format. | 
| 1793 | 
< | 
        <li> <a HREF="../man_html/ra_pict.1.html"><b>Ra_pict</b></a> | 
| 1794 | 
< | 
                converts to Macintosh 32-bit PICT2 format. | 
| 1846 | 
> | 
        <li> <a HREF="../man_html/ra_bmp.1.html"><b>Ra_bmp</b> | 
| 1847 | 
> | 
                converts to and from BMP image format. | 
| 1848 | 
  | 
        <li> <a HREF="../man_html/ra_ppm.1.html"><b>Ra_ppm</b></a> | 
| 1849 | 
  | 
                converts to and from Poskanzer Portable Pixmap formats. | 
| 1797 | 
– | 
        <li> <a HREF="../man_html/ra_pr.1.html"><b>Ra_pr</b></a> | 
| 1798 | 
– | 
                converts to and from Sun 8-bit rasterfile format. | 
| 1799 | 
– | 
        <li> <a HREF="../man_html/ra_pr24.1.html"><b>Ra_pr24</b></a> | 
| 1800 | 
– | 
                converts to and from Sun 24-bit rasterfile format. | 
| 1850 | 
  | 
        <li> <a HREF="../man_html/ra_ps.1.html"><b>Ra_ps</b></a> | 
| 1851 | 
  | 
                converts to PostScript color and greyscale formats. | 
| 1852 | 
  | 
        <li> <a HREF="../man_html/ra_rgbe.1.html"><b>Ra_rgbe</b></a> | 
| 1872 | 
  | 
<pre> | 
| 1873 | 
  | 
The Radiance Software License, Version 1.0 | 
| 1874 | 
  | 
 | 
| 1875 | 
< | 
Copyright (c) 1990 - 2010 The Regents of the University of California, | 
| 1875 | 
> | 
Copyright (c) 1990 - 2014 The Regents of the University of California, | 
| 1876 | 
  | 
through Lawrence Berkeley National Laboratory.   All rights reserved. | 
| 1877 | 
  | 
 | 
| 1878 | 
  | 
Redistribution and use in source and binary forms, with or without | 
| 1906 | 
  | 
      nor may "Radiance" appear in their name, without prior written | 
| 1907 | 
  | 
      permission of Lawrence Berkeley National Laboratory. | 
| 1908 | 
  | 
 | 
| 1909 | 
< | 
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED | 
| 1909 | 
> | 
THIS SOFTWARE IS PROVIDED ``AS IS" AND ANY EXPRESSED OR IMPLIED | 
| 1910 | 
  | 
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | 
| 1911 | 
  | 
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | 
| 1912 | 
  | 
DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR | 
| 1945 | 
  | 
</h2> | 
| 1946 | 
  | 
<p> | 
| 1947 | 
  | 
<ul> | 
| 1948 | 
+ | 
    <li>Wang, Taoning, Gregory Ward, Eleanor Lee, | 
| 1949 | 
+ | 
      "<a href="https://authors.elsevier.com/a/1XQ0a1M7zGwT7v">Efficient | 
| 1950 | 
+ | 
      modeling of optically-complex, non-coplanar exterior shading: | 
| 1951 | 
+ | 
      Validation of matrix algebraic methods</a>" | 
| 1952 | 
+ | 
      <em>Energy & Buildings</em>, vol. 174, pp. 464-83, Sept. 2018. | 
| 1953 | 
+ | 
    <li>Lee, Eleanor S., David Geisler-Moroder, Gregory Ward, | 
| 1954 | 
+ | 
      "<a href="https://eta.lbl.gov/sites/default/files/publications/solar_energy.pdf">Modeling | 
| 1955 | 
+ | 
      the direct sun component in buildings using matrix | 
| 1956 | 
+ | 
      algebraic approaches: Methods and | 
| 1957 | 
+ | 
      validation</a>," <em>Solar Energy</em>, | 
| 1958 | 
+ | 
      vol. 160, 15 January 2018, pp 380-395. | 
| 1959 | 
+ | 
    <li>Narain, Rahul, Rachel A. Albert, Abdullah Bulbul, | 
| 1960 | 
+ | 
       Gregory J. Ward, Marty Banks, James F. O'Brien, | 
| 1961 | 
+ | 
       "<a href="http://graphics.berkeley.edu/papers/Narain-OPI-2015-08/index.html">Optimal | 
| 1962 | 
+ | 
       Presentation of Imagery with Focus | 
| 1963 | 
+ | 
       Cues on Multi-Plane Displays</a>," | 
| 1964 | 
+ | 
       <em>SIGGRAPH 2015</em>. | 
| 1965 | 
+ | 
    <li>Ward, Greg, Murat Kurt, and Nicolas Bonneel, | 
| 1966 | 
+ | 
        "<a href="papers/WMAM14_Tensor_Tree_Representation.pdf">Reducing | 
| 1967 | 
+ | 
        Anisotropic BSDF Measurement to Common Practice</a>," | 
| 1968 | 
+ | 
        <em>Workshop on Material Appearance Modeling</em>, 2014. | 
| 1969 | 
+ | 
    <li>Banks, Martin, Abdullah Bulbul, Rachel Albert, Rahul Narain, | 
| 1970 | 
+ | 
        James F. O'Brien, Gregory Ward, | 
| 1971 | 
+ | 
        "<a href="http://graphics.berkeley.edu/papers/Banks-TPO-2014-05/index.html">The | 
| 1972 | 
+ | 
        Perception of Surface Material from Disparity and Focus Cues</a>," | 
| 1973 | 
+ | 
        <em>VSS 2014</em>. | 
| 1974 | 
+ | 
    <li>McNeil, A., C.J. Jonsson, D. Appelfeld, G. Ward, E.S. Lee, | 
| 1975 | 
+ | 
        "<a href="http://gaia.lbl.gov/btech/papers/4414.pdf"> | 
| 1976 | 
+ | 
        A validation of a ray-tracing tool used to generate | 
| 1977 | 
+ | 
        bi-directional scattering distribution functions for | 
| 1978 | 
+ | 
        complex fenestration systems</a>," | 
| 1979 | 
+ | 
        <em>Solar Energy</em>, 98, 404-14, | 
| 1980 | 
+ | 
        November 2013. | 
| 1981 | 
+ | 
    <li>Ward, G., R. Mistrick, E.S. Lee, A. McNeil, J. Jonsson, | 
| 1982 | 
+ | 
        "<a href="http://gaia.lbl.gov/btech/papers/4414.pdf">Simulating | 
| 1983 | 
+ | 
        the Daylight Performance of Complex Fenestration Systems | 
| 1984 | 
+ | 
        Using Bidirectional Scattering Distribution Functions within | 
| 1985 | 
+ | 
        Radiance</a>," | 
| 1986 | 
+ | 
        <em>Leukos</em>, 7(4) | 
| 1987 | 
+ | 
        April 2011. | 
| 1988 | 
  | 
    <li>Cater, Kirsten, Alan Chalmers, Greg Ward, | 
| 1989 | 
  | 
        "<a href="http://www.anyhere.com/gward/papers/egsr2003.pdf">Detail to Attention: | 
| 1990 | 
  | 
        Exploiting Visual Tasks for Selective Rendering</a>," | 
| 1991 | 
  | 
        <em>Eurographics Symposium | 
| 1992 | 
  | 
        on Rendering 2003</em>, June 2003. | 
| 1993 | 
  | 
    <li>Ward, Greg, Elena Eydelberg-Vileshin, | 
| 1994 | 
< | 
        ``<a HREF="http://www.anyhere.com/gward/papers/egwr02/index.html">Picture Perfect RGB | 
| 1995 | 
< | 
        Rendering Using Spectral Prefiltering and Sharp Color Primaries</a>,'' | 
| 1994 | 
> | 
        "<a HREF="http://www.anyhere.com/gward/papers/egwr02/index.html">Picture Perfect RGB | 
| 1995 | 
> | 
        Rendering Using Spectral Prefiltering and Sharp Color Primaries</a>," | 
| 1996 | 
  | 
        Thirteenth Eurographics Workshop on Rendering (2002), | 
| 1997 | 
  | 
        P. Debevec and S. Gibson (Editors), June 2002. | 
| 1998 | 
  | 
    <li>Ward, Gregory, | 
| 1999 | 
< | 
        ``<a HREF="http://www.anyhere.com/gward/papers/cic01.pdf">High Dynamic Range Imaging</a>,'' | 
| 1999 | 
> | 
        "<a HREF="http://www.anyhere.com/gward/papers/cic01.pdf">High Dynamic Range Imaging</a>," | 
| 2000 | 
  | 
        Proceedings of the Ninth Color Imaging Conference, November 2001. | 
| 2001 | 
  | 
    <li>Ward, Gregory and Maryann Simmons, | 
| 2002 | 
< | 
        ``<a HREF="http://www.anyhere.com/gward/papers/tog99.pdf"> | 
| 2002 | 
> | 
        "<a HREF="http://www.anyhere.com/gward/papers/tog99.pdf"> | 
| 2003 | 
  | 
        The Holodeck Ray Cache: An Interactive Rendering System for Global Illumination in Nondiffuse | 
| 2004 | 
< | 
        Environments</a>,'' ACM Transactions on Graphics, 18(4):361-98, October 1999. | 
| 2005 | 
< | 
    <li>Larson, G.W., ``<a HREF="http://www.anyhere.com/gward/papers/ewp98.pdf">The Holodeck: A Parallel | 
| 2006 | 
< | 
        Ray-caching Rendering System</a>,'' Proceedings of the Second | 
| 2004 | 
> | 
        Environments</a>," ACM Transactions on Graphics, 18(4):361-98, October 1999. | 
| 2005 | 
> | 
    <li>Larson, G.W., "<a HREF="http://www.anyhere.com/gward/papers/ewp98.pdf">The Holodeck: A Parallel | 
| 2006 | 
> | 
        Ray-caching Rendering System</a>," Proceedings of the Second | 
| 2007 | 
  | 
        Eurographics Workshop on Parallel Graphics and Visualisation, | 
| 2008 | 
  | 
        September 1998. | 
| 2009 | 
  | 
    <li>Larson, G.W. and R.A. Shakespeare, | 
| 2011 | 
  | 
        the Art and Science of Lighting Visualization</em></a>, | 
| 2012 | 
  | 
        Morgan Kaufmann Publishers, 1998. | 
| 2013 | 
  | 
    <li>Larson, G.W., H. Rushmeier, C. Piatko, | 
| 2014 | 
< | 
        ``<a HREF="http://radsite.lbl.gov/radiance/papers/lbnl39882/tonemap.pdf">A Visibility | 
| 2014 | 
> | 
        "<a HREF="http://radsite.lbl.gov/radiance/papers/lbnl39882/tonemap.pdf">A Visibility | 
| 2015 | 
  | 
        Matching Tone Reproduction Operator for | 
| 2016 | 
< | 
        High Dynamic Range Scenes</a>,'' LBNL Technical Report 39882, | 
| 2016 | 
> | 
        High Dynamic Range Scenes</a>," LBNL Technical Report 39882, | 
| 2017 | 
  | 
        January 1997. | 
| 2018 | 
< | 
    <li>Ward, G., ``<a HREF="http://radsite.lbl.gov/radiance/papers/erw95.1/paper.html">Making | 
| 2019 | 
< | 
        Global Illumination User-Friendly</a>,'' Sixth | 
| 2018 | 
> | 
    <li>Ward, G., "<a HREF="http://radsite.lbl.gov/radiance/papers/erw95.1/paper.html">Making | 
| 2019 | 
> | 
        Global Illumination User-Friendly</a>," Sixth | 
| 2020 | 
  | 
        Eurographics Workshop on Rendering, Springer-Verlag, | 
| 2021 | 
  | 
        Dublin, Ireland, June 1995.</li> | 
| 2022 | 
  | 
    <li>Rushmeier, H., G. Ward, C. Piatko, P. Sanders, B. Rust, | 
| 2023 | 
< | 
        ``<a HREF="http://radsite.lbl.gov/mgf/compare.html"> | 
| 2023 | 
> | 
        "<a HREF="http://radsite.lbl.gov/mgf/compare.html"> | 
| 2024 | 
  | 
        Comparing Real and Synthetic Images: Some Ideas about | 
| 2025 | 
< | 
        Metrics</a>,'' Sixth Eurographics Workshop on Rendering, | 
| 2025 | 
> | 
        Metrics</a>," Sixth Eurographics Workshop on Rendering, | 
| 2026 | 
  | 
        Springer-Verlag, Dublin, Ireland, June 1995.</li> | 
| 2027 | 
< | 
    <li>Ward, G., ``<a HREF="http://radsite.lbl.gov/radiance/papers/sg94.1/paper.html">The RADIANCE | 
| 2028 | 
< | 
        Lighting Simulation and Rendering System</a>,'' <em>Computer | 
| 2027 | 
> | 
    <li>Ward, G., "<a HREF="http://radsite.lbl.gov/radiance/papers/sg94.1/paper.html">The RADIANCE | 
| 2028 | 
> | 
        Lighting Simulation and Rendering System</a>," <em>Computer | 
| 2029 | 
  | 
        Graphics</em>, July 1994.</li> | 
| 2030 | 
< | 
    <li>Rushmeier, H., G. Ward, ``<a HREF="http://radsite.lbl.gov/radiance/papers/sg94.2/energy.html">Energy | 
| 2031 | 
< | 
        Preserving Non-Linear Filters</a>,'' <em>Computer | 
| 2030 | 
> | 
    <li>Rushmeier, H., G. Ward, "<a HREF="http://radsite.lbl.gov/radiance/papers/sg94.2/energy.html">Energy | 
| 2031 | 
> | 
        Preserving Non-Linear Filters</a>," <em>Computer | 
| 2032 | 
  | 
        Graphics</em>, July 1994.</li> | 
| 2033 | 
< | 
    <li>Ward, G., ``A Contrast-Based Scalefactor for Luminance | 
| 2034 | 
< | 
        Display,'' <em>Graphics Gems IV</em>, Edited by Paul Heckbert, | 
| 2033 | 
> | 
    <li>Ward, G., "A Contrast-Based Scalefactor for Luminance | 
| 2034 | 
> | 
        Display," <em>Graphics Gems IV</em>, Edited by Paul Heckbert, | 
| 2035 | 
  | 
        Academic Press 1994.</li> | 
| 2036 | 
< | 
    <li>Ward, G., ``<a HREF="http://radsite.lbl.gov/radiance/papers/sg92/paper.html">Measuring and | 
| 2037 | 
< | 
        Modeling Anisotropic Reflection</a>,'' <em>Computer | 
| 2036 | 
> | 
    <li>Ward, G., "<a HREF="http://radsite.lbl.gov/radiance/papers/sg92/paper.html">Measuring and | 
| 2037 | 
> | 
        Modeling Anisotropic Reflection</a>," <em>Computer | 
| 2038 | 
  | 
        Graphics</em>, Vol. 26, No. 2, July 1992. </li> | 
| 2039 | 
< | 
    <li>Ward, G., P. Heckbert, ``<a HREF="http://radsite.lbl.gov/radiance/papers/erw92/paper.html">Irradiance | 
| 2040 | 
< | 
        Gradients</a>,'' Third Annual Eurographics Workshop on | 
| 2039 | 
> | 
    <li>Ward, G., P. Heckbert, "<a HREF="http://radsite.lbl.gov/radiance/papers/erw92/paper.html">Irradiance | 
| 2040 | 
> | 
        Gradients</a>," Third Annual Eurographics Workshop on | 
| 2041 | 
  | 
        Rendering, Springer-Verlag, May 1992. </li> | 
| 2042 | 
< | 
    <li>Ward, G., ``<a HREF="http://radsite.lbl.gov/radiance/papers/erw91/erw91.html">Adaptive Shadow | 
| 2043 | 
< | 
        Testing for Ray Tracing</a>'' Photorealistic Rendering in | 
| 2042 | 
> | 
    <li>Ward, G., "<a HREF="http://radsite.lbl.gov/radiance/papers/erw91/erw91.html">Adaptive Shadow | 
| 2043 | 
> | 
        Testing for Ray Tracing</a>" Photorealistic Rendering in | 
| 2044 | 
  | 
        Computer Graphics, proceedings of 1991 Eurographics | 
| 2045 | 
  | 
        Rendering Workshop, edited by P. Brunet and F.W. Jansen, | 
| 2046 | 
  | 
        Springer-Verlag. </li> | 
| 2047 | 
< | 
    <li>Ward, G., ``Visualization,'' <em>Lighting Design and | 
| 2047 | 
> | 
    <li>Ward, G., "Visualization," <em>Lighting Design and | 
| 2048 | 
  | 
        Application</em>, Vol. 20, No. 6, June 1990. </li> | 
| 2049 | 
< | 
    <li>Ward, G., F. Rubinstein, R. Clear, ``<a HREF="http://radsite.lbl.gov/radiance/papers/sg88/paper.html">A Ray Tracing Solution for | 
| 2050 | 
< | 
        Diffuse Interreflection</a>,'' <em>Computer Graphics</em>, | 
| 2049 | 
> | 
    <li>Ward, G., F. Rubinstein, R. Clear, "<a HREF="http://radsite.lbl.gov/radiance/papers/sg88/paper.html">A Ray Tracing Solution for | 
| 2050 | 
> | 
        Diffuse Interreflection</a>," <em>Computer Graphics</em>, | 
| 2051 | 
  | 
        Vol. 22, No. 4, August 1988. </li> | 
| 2052 | 
< | 
    <li>Ward, G., F. Rubinstein, ``A New Technique for Computer | 
| 2053 | 
< | 
        Simulation of Illuminated Spaces,'' <em>Journal of the | 
| 2052 | 
> | 
    <li>Ward, G., F. Rubinstein, "A New Technique for Computer | 
| 2053 | 
> | 
        Simulation of Illuminated Spaces," <em>Journal of the | 
| 2054 | 
  | 
        Illuminating Engineering Society</em>, Vol. 17, No. 1, | 
| 2055 | 
  | 
        Winter 1988. </li> | 
| 2056 | 
  | 
</ul> |