• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.9 no.3
• /
• pp.47-61
• /
• 2014

Many angel investors hesitate to invest in early-stage company. Most early-stage company has no sales and only R&D step project or in early approach of market. So it's impossible to evaluate early-stage company quantitatively. Therefore many angel investors depend on CEO's tendency to evaluate company and make decision for investment. The purpose of this study is discover the entrepreneurial characteristics of CEO and the importance level which affect on the angel investors decision making factors for investment. To identify the factors of entrepreneurial characteristics, survey was conducted by Delphi Technique which is involved by 20 experts who is angel investment club members, venture capitalists, CEOs and officers. Three rounds of survey results derived 10 elements of entrepreneurial characteristics for investment decision making factors including reliability, risk sensitivity, passion, perseverance, integrity, leadership, startup experience, organizational management skills, innovation and social networking. In addition, this study derived the importance level of elements of entrepreneurial characteristics based on the AHP(Analytic Hierarchy Process) theory and maintained the logical consistency by pair-wise comparison for each element. As a result of analyzing the importance of entrepreneurial characteristics, the sequence is reliability (18.1%), integrity (15.9%), leadership (11.7%), organizational management skills (10.0%), social networking (9.5%), passion(9.1%), perseverance(8.4%), innovation(8.1%), startup experience(5.3%) and risk sensitivity(3.9%) respectively. The significance of this study is somewhat decrease limit of the uncertainty arising from angel investors and angel investors can help a decision making, by discover factors of entrepreneurial characteristics that can be called the biggest influencing factors among Investor's investment decision-making In early stage companies and compare importance.

• Journal of the Korean Institute of Gas
• /
• v.24 no.4
• /
• pp.62-72
• /
• 2020

This study presents a methodology of history matching to evaluate the productivity of shale gas reservoir with high reliability and predict future production rate in the Horn-River basin, Canada. Sensitivity analysis was performed to analyze the effect of physical properties of shale gas reservoir on productivity. Based on the results, reservoir properties were classified into 4 cases and history matching were performed considering the classified 4 cases as objective function. The blind test was conducted using additional field production data for 3 years after the history matching period. The error of gas production rate in Case 1(all reservoir parameters), Case 2(influenced parameters for productivity), Case 3(controllable parameters), and Case 4(uncontrollable parameters) were 7.67%, 7.13%, 17.54%, and 10.04%, respectively. This means that it seems to be effective to consider all reservoir parameters in early period for 4 years but Case 2 which considered influenced parameters for productivity shows the highest reliability in predicting future production. The estimated ultimate recovery (EUR) of production well predicted using the Case 2 model was estimated to be 17.24 Bcf by December 2030 and the recovery factor compared to original gas in place (OGIP) was 32.2%.

• Management & Information Systems Review
• /
• v.38 no.2
• /
• pp.209-223
• /
• 2019

The purpose of this study was to stimulate the online word-of-mouth advertising by developing the concept of word-of-mouth constraint factors and measurement tools in connection with the SNS advertising on social networks. To achieve the objective of this study, this study was conducted in 3 phases. First, the exploratory investigation(target group interview, in-depth interview, and expert interview) was performed to determine the concept and scope of the word-of-mouth constraint based on literature study and qualitative investigation method. Second, the reliability and validity of the measurement questions were verified through the survey in order to refine the developed measurement items. Third, the predictive validity of measurement items was verified by examining the relationship with other major construct concept for which the developed measurement items were different. Based on the results of study, 6 components and a total of 23 measurement questions for those components were derived. Each was called intrapersonal and interpersonal constraint(psychological sensitivity, compensatory sensitivity, and other person assessment), structural constraint(reliability, informativity, and entertainment). We developed the measurement questions related to word-of-mouth constraint based on qualitative study and quantitative study and holistically examined the social and psychological, environmental interruption factors acting as the word-of-mouth constraint factors for SNS advertising in terms of SNS achievements and evaluation from the perspective of word-of-mouth constraint. The results will lead to creation of basic framework for systematic and empirical research on the online word-of-mouth constraint and to achievement of effective SNS word-of-mouth advertising.

• Journal of Korean Neurosurgical Society
• /
• v.67 no.1
• /
• pp.94-102
• /
• 2024

Objective : The spontaneous intracerebral hemorrhage (ICH) remains a significant cause of mortality and morbidity throughout the world. The purpose of this retrospective study is to develop multiple models for predicting ICH outcomes using machine learning (ML). Methods : Between January 2014 and October 2021, we included ICH patients identified by computed tomography or magnetic resonance imaging and treated with surgery. At the 6-month check-up, outcomes were assessed using the modified Rankin Scale. In this study, four ML models, including Support Vector Machine (SVM), Decision Tree C5.0, Artificial Neural Network, Logistic Regression were used to build ICH prediction models. In order to evaluate the reliability and the ML models, we calculated the area under the receiver operating characteristic curve (AUC), specificity, sensitivity, accuracy, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR). Results : We identified 71 patients who had favorable outcomes and 156 who had unfavorable outcomes. The results showed that the SVM model achieved the best comprehensive prediction efficiency. For the SVM model, the AUC, accuracy, specificity, sensitivity, PLR, NLR, and DOR were 0.91, 0.92, 0.92, 0.93, 11.63, 0.076, and 153.03, respectively. For the SVM model, we found the importance value of time to operating room (TOR) was higher significantly than other variables. Conclusion : The analysis of clinical reliability showed that the SVM model achieved the best comprehensive prediction efficiency and the importance value of TOR was higher significantly than other variables.

• Journal of the Korean GEO-environmental Society
• /
• v.17 no.12
• /
• pp.55-64
• /
• 2016

In this paper bearing capacity and safety margin of shallow foundation on weathered soil ground against shear failure by using current design method of allowable stress design (ASD), load resistance factor design (LRFD) based on reliability analysis and partial safety factor design (PSFD) in Eurocode were estimated and compared to each other. Results of the plate loading test used in construction and design were collected and analysis of probability statistics on soil parameters affecting the bearing capacity of shallow foundation was performed to quantify the uncertainty of them and to investigate the resistance bias factor and covalence of ultimate bearing capacity. For the typical sections of shallow foundation in domestic field as examples, reliability index was obtained by reliability analysis (FORM) and the sensitivity analysis on soil parameters of probability variables was performed to investigate the effect of probability variable on shear failure. From stability analysis for these sections by ASD, LRFD with the target reiability index corresponding to the safety factor used in ASD and PSDF, safety margins were estimated respectively and compared.

• The Journal of Korean Medicine
• /
• v.17 no.1 s.31
• /
• pp.48-83
• /
• 1996

Our conclusions for function evaluation tools of Stroke patients are as follows. 1. Evaluating tools of Activities of Daily Living, Katz Index, Barthel Index, Modified Barthel Index have high validity and reliability because of ease of measuring, high accuracy, consistency, sensitivity and sufficient stastistics, but they mainly measure motor function except sense, mentation, language, and social conception. Therefore cerebrovascular disease and brain injury in trauma patients with lacked acknowledgement and sensation, we are not able to apply these tools. 2. PULSES Profile is a useful scale for measuring the patient's over-all status, upper and lower limb functions, sensory components, excretary functions, and intellectual and emotional adaptabilities. It is recognized as a good, useful tool to evaluate patient's whole function. 3. Motor Assessment Scale was designed to measure the progress of stroke patients. The scale was supplemented with upper arm function items. We believe that the Motor Assessment Scale could be a useful evaluation tool with inter-rater reliability ,test-retest reliability. 4. The existing evaluation tools, Katz Index, Barthel Index, Modified Barthel Index, PULSES Profile, Motor Assessment Scale, mainly measured the rehabilitational motor function of sequela of cerebrovascular patients. On the other hand CNS & INH stroke scale can measure cerebrovascular disease patient's neurologic deficits and over-all stautus, which are recognition ability, speech status, motor function, sensory function, activities of daily living. Those scales have been recognized as useful tools to measure function of cerebrovascular disease patients and have increased in use. 5. Every function evaluation tool was recognized to have some validity and inter-rater, test-retest reliability in items of each evaluation tool and total scores of each evaluation tools, but it is thought that none of these scales have been fully validated and proved reliable. Therefore afterward, the development of a highly reliable rating system may best be accomplished by a careful comparison of several tools, using the same patients and the same observers in order to choose the most reliable items from each. 6. Ideal evaluation tools must have the following conditions; (1) It should show the objective functional statues at the same time. (2) It should be repeated consecutively to know changed function status. (3) It should be easy to observe the treatment program. (4) It should have the same result with another rater to help rater exchange information with treatment team members. (5) It should be practical and simple. (6) The patient should not suffer from the observer.

• Journal of Korean Clinical Nursing Research
• /
• v.29 no.2
• /
• pp.198-209
• /
• 2023

Purpose: The purpose of this study was to develop a Korean Adult Patients Delirium Screening Tool (K-APDS) for those admitted to general wards, and to verify its reliability and validity. Methods: For the development of the tool, 12 items were derived through the results of literature review and focus group interviews with general ward nurses, and the content validity was confirmed by experts. To verify the reliability and validity of the developed tool, 317 adult patients who were admitted to general wards of three tertiary general hospitals from October to November 2022 were evaluated by the attending nurse and data were collected. Results: After factor analysis for construct validity verification, two factors were extracted, which explained 60.1% of the total variance. After the validation of the control group, the difference in the delirium incidence scores calculated using the K-APDS between the delirium group and non-delirium group was very significant (Z=-10.82, p<.001). To verify the criterion validity, K-APDS, Delirium Observation Screening, and Pearson's correlation coefficient were checked and found to be .94 (p<.001). The predictive validity test reported that the sensitivity was 91.1%, specificity was 82.4%, positive predictive value was 52.6%, and negative predictive value was 97.8%. The reliability of K-APDS was found to be high with Cronbach's ⍺=.91. Conclusion: K-APDS can screen for delirium with 2 or more points, excellent validity and reliability have been verified. Therefore, this tool could be applied immediately in the clinical field, and will contribute to the early detection of delirium, enabling rapid interventions.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.1
• /
• pp.129-135
• /
• 2003

Optical fiber has many advantages, such as high reliability, long lifetime, immunity to the electromagnetic interference, high speed response and low cost. In this study, we proposed and developed an optical fiber impact and pressure sensor for prevention of accident which occurs in the automatic system or auto door. The principle of the sensor is to detect different optical intensity caused by variation of a speckle pattern due to the external perturbation. Speckle pattern appears at the end of a multimode fiber in which coherent beam propagates. The fabricated sensor in this study was tested. As a result of experiments, amplitude of the output signal isn't linear, but it has sufficient sensitivity for a sensor. Moreover, we can control sensitivity of the sensor by an amplifier at receiver. It has several advantages which are ability of detection at all point on the multimode fiber, large sensitive area, and many application areas for a sensing impact and pressure.

• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.3
• /
• pp.185-190
• /
• 2016

Damages of the main engine aftmost bearing and the after stern tube bearing tend to increase due to misalignment. And as the shafting system becomes stiffer due to the large engine power, whereas the hull structure becomes more flexible due to optimization by using high tensile thin steel plates. And this is the reason that more sophisticated shaft alignments are required. In this study, the optimum shafting alignment calculation was carried out, considering the thermal expansion effect, exploiting the sensitivity index, which indicates the reasonable position of forward intermediate shaft bearing for shaft alignment. and as the main subject in this study, the elastic deformation on intermediate shaft and main engine bearings occurred by vertical load of shaft mass were examined thoroughly and analyzed allowable load of bearings, reaction influence numbers of all bearings. As the result, a reliable optimum shafting alignment was derived theoretically. To verify these results, they were referred to the engine maker's technical information of main engine installation and being used shafting alignment programs of both Korean Register of Shipping and Det Norske Veritas, their reliability were reviewed.

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.2
• /
• pp.171-179
• /
• 2014

In this study, a novel method was proposed to test the integrity of water treatment system specifically equipped with membrane filtration process. We applied the silica particles coated with a fluorescent agent (rhodamine B isothiocyanate) as a surrogate to detect a membrane process integrity and evaluate the reliability of effluent quality in the system. Additionally, a series of experiments was conducted to evaluate the sensitivity of the method through the laboratory scale experiment. The laboratory scale experiments showed that the feasibility of application of proposed method to detect a breach or damaged part on the membrane surface. However, the sensitivity on predicting the area of a breach was significantly influenced by the testing conditions such as a concentration of surrogate, filtration flux, and detection time. The lowest error of predicting the area of breach was 3.5% at the testing condition of surrogate concentration of 80 mg/L injected with flux of $20L/m^2/hr$ for 10 minutes of detection time for the breach having the actual area of $7.069mm^2$. However, the error of estimation was increased at the small breach with area less than $0.785mm^2$. A future study will be conducted to estimate a damaged area with more accuracy and precision.