Samsung Heavy Industries Co., a major South Korean shipbuilder, said Friday that its second-quarter net profit soared 12% from a year earlier on the back of increased demand for high-priced ships and cost-cutting efforts reported the South Korean Yonhap news agency . Net profit reached 215 billion won (US$191 million) in the April-June period, compared with a profit of 193 billion won a year earlier, the company said in a regulatory filing.