• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.6
• /
• pp.1634-1647
• /
• 2007

"To invest or not to invest?" Most business leaders are frequently faced with this question on new and ongoing projects. The challenge lies in deciding what projects to choose, expand, contract, defer, or abandon. The project valuation tools used in this process are vital to making the right decisions. Traditional tools such as discounted cash flow (DCF)/net present value (NPV) assume a "fixed" path ahead, but real world projects face uncertainties, forcing us to change the path often. Comparing to other traditional valuation methods, the real options approach captures the flexibility inherent to investment decisions. The use of real options has gained wide acceptance among practitioners in a number of several industries during the last few decades. Even though the options are present in all types of business decisions, it is still not considered as a proper method of valuation in some industries. Mining has been comparably slow to adopt new valuation techniques over the years. The reason fur this is not entirely clear. One possible reason is the level and types of risks in mining. Not only are these risks high, but they are also more numerous and involve natural risks compared with other industries. That is why the purpose of this study is to deal with a more practical approach to project valuation, known as real options analysis in mining industry. This paper provides a case study approach to the copper mining industry using a real options analysis. It shows how companies can minimize investment risks, exercise flexibility in decision making and maximize returns.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.6
• /
• pp.1572-1578
• /
• 2007

The specified wastes consist of waste acid, waste alkali, waste oil, waste organic solvent, waste resin, dust, sludge, infectious waste, and others. Among these specified wastes, a great portion is liquid phase wastes. The purpose of this study is to develop the high temperature and high pressure (HTHP) treatment system for decomposition of the liquid phase specified waste (LPSW). For this, we analyzed the physical and chemical properties of the LPSW such as density, proximate analysis, ultimate analysis, heating values, and designed 0.3 ton/day HTHP treatment system. The LPSW tested in this experiment were prepared by adding TCE(trichloroethylene) and toluene to liquid phase waste which was brought into the commercial waste treatment company. The average density of waste oil (25 samples), waste resin (5 samples), and waste solvent (12 samples) was 0.99 g/mL, 0.91 g/mL, and 0.93 g/mL, respectively. And the average lower heating value of waste oil, waste resin, and waste solvent was 8,294 kcal/kg, 5,809 kcal/kg, and 7,462 kcal/kg, respectively. The DRE (Destruction & Removal Efficiency) of TCE and toluene were 99.95% and 99.73% at atmospheric pressure conditions and that were 99.99% and 99.82% at pressurized conditions, respectively. These results showed that TCE/toluene mixtures were properly decomposed over about 99.73% of DRE by the HTHP treatment system and pressurized conditions were more effective to destroy those pollutants than atmospheric pressure conditions. Also these systems could be directly applied to industries which try to treat the liquid phase specified waste within the regulation limit.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.11
• /
• pp.7524-7533
• /
• 2015

The purpose of this study was to investigate the effects of purple sweet potato(PSP) intake and aerobic combined exercise in obese middle school girls. Twenty-four, obese(%body fat > 30%) middle school girls composed of the purple sweet potato intake and aerobic combined exercise group(A, n=6), the aerobic combined exercise group(B, n=6), the purple sweet potato intake group(C, n=6), the control group(D, n=6). The variables of health related fitness, blood lipid profile, insulin resistance were measured in all the subjects before the start and after the end of 12 week aerobic combined exercise program(40~70%HRR, 3 times per week, 70 mins). The test data were analyzed by paired t-test and one way ANOVA, and the alpha level of p<.05 was set for all tests of significance. In the comparison within each group, %body fat[A(p<.01), C(p<.05) groups], TC[A(p<.05), B(p<.01), C(p<.01) groups] and insulin resistance[A(p<.05) group] were significantly decreased and LBM[A(p<.01), B(p<.01) groups], muscular strength[A(p<.01), B(p<.001), C(p<.05) groups], muscular endurance[A(p<.05), B(p<.001) groups], flexibility[A(p<.05), B(p<.01) groups] and cardiorespiratory endurance[A(p<.05), B(p<.001), C(p<.01) groups] were significantly increased. In the comparison between groups, A group was significantly decreased in %body fat, TC and TG than D group(p<.05). A group was significantly increased in muscular strength and cardiorespiratory endurance than C, D groups (p<.05). A group was significantly increased in muscular endurance and HDL-C than D group(p<.05). A, B groups were significantly increased in flexibility than D group(p<.05). A, B, C groups were significantly decreased in insulin resistance than D group(p<.05). In conclusion, purple sweet potato intake and aerobic combined exercise were effective in improving the health related fitness, blood lipid profile and insulin resistance in obese middle school girls.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.11
• /
• pp.7227-7236
• /
• 2015

The survey revealed that, due to the discharge characteristics of seafood wastewater, irregular inflow loads were caused, making it difficult to treat the wastewater safely. It is crucial for the operation of pressure and floating tanks for the treatment of high-concentration organic wastewater such as seafood wastewater. The survey of operation factors for the pressure and floating tanks revealed this: A/S ratio 0.05 (design criteria 0.01), the pressurized air pressure 8bar(design criteria 6bar), the pressure tank pressure 6bar (design criteria 4.5bar), and HRT 60sec(design criteria: 10sec). Also, the recirculation rate was changed to over 40%(design criteria: 30%), and the surface load rate was changed to under $13.7m^3/m^2{\cdot}hr$(design criteria: under $17.7m^3/m^2{\cdot}hr$); thus, compared to the initial design criteria, the operation factors were changed according to inflow characteristics, thus enhancing the pressure and floating tank performance. The survey of inflow load revealed BOD 140.7%, $COD_{Mn}$ 120.32%, and SS 106.3%, compared to the inflow design criteria, as well as T-N 135.5% and T-P173.3%, higher than the design criteria. The survey of the treatment facility annual operation cost revealed high portions in sludge treatment cost(27.7%) and chemicals costs(26.0%), and the sludge treatment cost will likely further increase due to the ban on ocean dumping. The unit cost for the treatment of seafood wastewater was found to be KRW 3,858 per ton, more than 27 times higher than the sewage treatment cost(KRW 142.6/ton), presumably because the seafood wastewater contains high-concentration organic substances and nutritive salts.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.11
• /
• pp.7978-7989
• /
• 2015

Dyslipidemia is a major risk factor for cardio-cerebrovascular disease. Although the prevalence among Korean adults is very high, its management is known to be poor. The aim of this study was to access the prevalence, awareness, treatment, and control rates of dyslipidemia according to treatment guideline rather than diagnostic criteria. The risk factors for cardio-cerebrovascular disease were evaluated to apply the appropriate risk-based threshold of the lipid treatment targets according to risk category. Analysis was done using nationally representative data (n = 16,263) collected from adults aged 20 years and older participating the Korea National Health and Nutrition Examination Survey (KNHANS) 2010-2012. The age-standardized prevalence rate of dyslipidemia according to treatment criteria was 34.1%. Of these prevalent cases, however, only 19.2% were aware; 9.5% treated; and 8.7% controlled. The age-standardized control rate among treated persons was 47.5%. Men had a significantly higher prevalence than women (39.7% vs. 28.8%), but a significantly lower rate of awareness, treatment, and control (16.0% vs. 22.3%, 7.7% vs. 11.3%, and 6.1% vs. 11.2%, respectively). As the higher risk category, the prevalence rate was higher but the control rate was lower. The prevalence of patients with diabetes was 82.5% when applying the treatment criteria (LDL-cholesterol level of ${\geq}100mg/dL$ and triglyceride level of ${\geq}200mg/dL$). However, only 11.9 % of these were controlled, whose LDL-cholesterol and triglycerides were lower than the treatment goals. Our findings suggest that effective strategies are required to decrease the gap between the prevalence of dyslipidemia and the following treatment. It would be worthwhile to strengthen the follow-up management of patients with dyslipidemia in the National Health Screening Program, especially in the high risk group of cardio-cerebrovascular disease.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.12
• /
• pp.5819-5826
• /
• 2011

Recently in the dental world, competition in the medical industry has been intensified due to the prolonged economic stagnation, the quantitative expansion of medical institutions, the enhancement of medical consumers'awareness of rights, and the diversity of medical consumer needs. Dental institution management of the difficulties is the requirement for dental institution to ensure competitiveness. So Word-of-Mouth marketing, which creates high marketing effectiveness with low cost, needs to be actively utilized as a new alternative to mass communication marketing. This research is to accurately grasp the target group of dental medical marketing activities through research on the degree of customer loyalty and Word-of-Mouth effects according to character trait of the patients visiting dental clinics, and to present the basic data for Word-of-Mouth marketing strategies from a viewpoint of practical business through presenting Word-of-Mouth promotion factors. To achieve this, questionnaire survey was conducted on 10 dental clinics located in Daegu for 4 weeks from April 11, 2011 to May 6, 2011 and 612 copies of responses to the questionnaires for final data for analysis were obtained. The results of the analysis are as follows. There were no significant differences in the degree of customer loyalty according to character trait of the subjects between the introverts and the extroverts, and the subjects with high market mavens propensity were found to show high degree of customer loyalty (F=5.243, p=.006). In the differences in Word-of-Mouth effectiveness according to character trait, there were greater differences in Word-of-Mouth experiences in the extrovert subjects ($x^2$=6.738, p=.006) and the subjects with high market mavens propensity ($x^2$=17.251, p=.000). The results of this research clarifies the degree of customer loyalty according to character trait of the patients visiting dental clinics and the differentiated influences of Word-of-Mouth effectiveness, and through this, they will become basic data for presenting ways to establish strategies from the viewpoint of practical business that should be considered in establishing dental medical marketing strategies.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.12
• /
• pp.5684-5691
• /
• 2011

The purpose of this study is to examine effects of constraint-induced movement therapy(CIMT) and/or cognitive-perceptual training(CPT) on the change of hand function in cerebrovascular accident(CVA) patients and to evaluate the change in the amount and quality of use of the affected upper extremity in performing daily living tasks. The subjects of study were 10 patients who had been under rehabilitation for more than three months after CVA onset. They were all determined as mild cognition impairment according to NCSE or MVPT test. For CIMT group, to restrict the movement of the unaffected hand the subjects had been worn modified resting arm-splint in daytime for 4 weeks. For CIMT+CPT group, the subjects were performed CPT with CIMT and control group had been under conventional occupational therapy for the same period. CIMT+CPT group showed significant improvement in simulated feeding, lifting large light objects, and lifting large heavy objects of Jebsen-Taylor Hand Function Test. CIMT group also showed significant improvement compared with control group. The mean changes of the amount of use(AOU) of the affected arm had a statistically significant difference among groups (p<.05). While CIMT+CPT group had the biggest change in the quality of movement(QOM) of upper extremity of the affected side, CTL group showed the smallest change. Both CIMT and CIMT+CPT groups had statistically significant difference in the change in the quality of movement in upper extremity of affected side with CTL group(p<.05), but there was not significant difference between CIMT group and CIMT+CPT group. CIMT performed to the patients of stroke, with mild impairment in cognitive perceptual abilities showed the improvement in hand movement and AOU and QOM of upper extremity in the affected side and the combination of CIMT with CPT showed synergic effects.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.8
• /
• pp.240-247
• /
• 2017

The increased investigation of the cerebral arteries with magnetic resonance angiography has resulted in an increase in the identification of unruptured intracranial aneurysms (UIAs). Knowledge of the distribution and factors associated with UIAs might be helpful for understanding the pathological mechanism of unruptured aneurysms. This study examined patients who visited a health care center and had a health examination from January 2007 to December 2016. Subjects who underwent magnetic resonance angiography with a health examination at the Health Screening were enrolled in this study. The incidence and risk factors of UIAs (age, sex, hypertension, diabetes mellitus, smoking, alcohol, and coronary artery disease) were investigated by comparing the size (more than 3 mm vs. less than 3 mm) and multiple aneurysm (single vs. multiple aneurysms). The frequency of aneurysm according to the site was also analyzed. Among the 187166 subjects, who received a health examination, 18954 underwent magnetic resonance angiography. Of them, 367 (1.93%) had UIAs. A comparison of the size of more than 3 mm and less than 3 mm showed that the mean age of the more than 3 mm group of patients was significantly higher than the other size groups (more than 3 mm $57.16{\pm}8.47$ vs. less than 3 mm $55.12{\pm}8.19$; p=0.07). High-density lipoprotein was significantly higher in the more than 3 mm group than in the less than 3 mm($55.95{\pm}16.03$ vs. less than 3 mm $50.85{\pm}13.65$; p=0.007). Hypertension was significantly higher in the multiple aneurysm group (single 153 in 399 (38.3%) VS multiple 19 in 35 (54.3%); p=0.065). An aneurysm of less than 3 mm in size was frequent in the distal internal carotid artery (34.3%) and MCA-bifurcation (16.4%) (p=0.003). Aneurysms of more than 3 mm were frequent in the distal internal carotid artery (43.4%) and MCA-bifurcation (13.4%), and anterior communicating artery (13.4%) (p=0.003). The difference in size and single or multiple aneurysm revealed other risk factors. These risk factors suggest that degenerative and hemodynamic disorders may lead to the presence of aneurysms.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.8
• /
• pp.367-377
• /
• 2017

This study examined the effects of the salinity of seafood wastewater on the sulfur denitrification process. An examination of the denitrification efficiency showed that the optimal EBCT was 1hr at an influent T-N concentration of 20mg/L or lower and 2-3hr at an T-N concentration of 30mg/L. An examination of the denitrification efficiency according to the nitrogen load showed that the legal effluent water quality criterion was satisfied when the influent load was maintained within $0.496kg/m^3/day$. On the other hand, the reactor volume increased when this was applied to the site. Therefore, the influent load should be within $0.372kg/m^3/day$ considering the denitrification and economic efficiency. At a load of $0.248{\sim}0.628kg/m^3{\cdot}day$, the k value was $0.0890{\sim}0.5032hr^{-1}$. The batch experimental results according to the $Cl^-$ concentration showed that at an influent nitrogen concentration of 30.0mg/L, the effect of the denitrification efficiency was not large below the salinity of $7,000mgCl^-/L$, but inhibition occurred above $9,000mgCl^-/L$. Calculations of the reaction rate constant according to the $Cl^-$ concentration showed that the reaction rate constant was $0.1049{\sim}0.2324hr^{-1}$ at a raw wastewater concentration of ${\sim}5,000mgCl^-/L$. In contrast, the k value was $0.1588hr^{-1}$ at $7,000mgCl^-/L$ and $0.1049hr^{-1}$ at $9,000mgCl^-/L$.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.5
• /
• pp.195-202
• /
• 2016

The government has run and managed various forms of direct payment systems, such as the paddy and field direct payment, to ease the instability of farm incomes with respect to market opening, and preserve farm income. Direct payments to the agricultural sector is a center in the key policy instrument that plays an important role in income stabilization. Despite the large amount of spending in the farm unit, the status of direct payment, and policy effects the analysis of direct payments, such as stability of income contribution, are insufficient. This paper, using the farm unit DB in 2014 and 2015, performed farm level analysis of direct payment, and derived the implications of the performance evaluation system. As a result, the distribution of direct payment showed considerable bias to the left side compared to the normal distribution curve. Approximately half of the farms (49.3%) in 2014 DB should receive below 100,000 won per year by a direct payment. A larger-scale farm showed a significantly increased income effect and income stabilizing effect because direct payments make higher contributions to farm income in proportional to the area. In the more elderly farmers, a high contribution by direct payment to farm income was found to be an advantage; however, in small-scale farms of less than 0.5ha, direct payment contribution on farm household income was only 3%. In large-scale farms, 10ha or more, the contribution to farm income were found to be 29.4%. The income of large farms was 10 times larger than small farmers, and the direct payment entitlements that were received were 110 times larger. Through this policy, direct payments are required for future improvements and modifications.