%--------------------------
 % @Author: Jingqiao Hu
 % @Date: 2021-12-23 12:26:08
 % @LastEditTime: 2021-12-23 12:26:13
%--------------------------
function [xval, xold1, xold2, xmin, xmax, low, upp, m_mma, c_mma, d_mma, a0_mma,  a_mma] = MMA_paras_simp(nele, volfrac)
    xval = repmat(volfrac, nele, 1); 
%     xval = ones(nele, 1);
    xval = xval(:);
    xold1= xval; xold2 = xval; 
    xmin = zeros(nele, 1); 
    xmax = ones(nele, 1); 
    xmin = xmin(:); xmax = xmax(:);
    low  = xmin; upp = xmax; 

    m_mma = 1; % number of constrain
    c_mma = 1000*ones(m_mma,1); d_mma = zeros(m_mma,1); a0_mma = 1; a_mma = zeros(m_mma,1); 
end