• Journal of Life Science
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• v.28 no.9
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• pp.1068-1075
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• 2018

Kaempferia parviflora, an herbaceous plant in the family Zingiberaceae, is popular in many tropical regions. It is called as black ginger or krachaidum in Thailand and Laos, and its raw or dried root have been used as spices and teas. The rhizomes also have been traditionally used to treat gastrointestinal disorders, ulcers, gout, dysentery, allergies and to improve physical work capacity. Recently, its anti-obesity, anti-oxidant, anti-inflammatory and blood clot-lysis activities were reported. In this study, the anti-thrombosis activity of black ginger was investigated, since improvement in blood fluidity leads to the prevention of various lifestyle-related diseases. The hot water and ethanol extract and their subsequent solvent fractions (hexane, ethylacetate, butanol fractions and water residue) were prepared, and their anti-coagulation and platelet aggregation inhibitory activities were determined, respectively. Among the black ginger extracts and their fractions, the ethylacetate fraction (EAF) of ethanol extract only showed significant extensions of blood coagulation time determined by thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (aPTT). At 5 mg/ml concentration, TT, PT and aPTT were extended to 1.22, 1.49 and >15-folds compared to non-treatment. The EAFs of ethanol and hot water extract showed strong inhibitions against collagen-induced platelet aggregations, which are comparable to inhibitions of aspirin. Also the EAFs from black ginger did not show any hemolysis activity against human RBC up to 0.5 mg/ml. Our results suggest that the EAF of black ginger has a potential as novel anti-coagulation and ant-platelet aggregation agent. This report provides the first evidence of anti-coagulation activity of black ginger.

• KDI Journal of Economic Policy
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• v.25 no.1
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• pp.99-145
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• 2003

Quasi-fiscal activities (QFAs) refer to those activities that public corporations carry out to achieve policy objectives of the government. QFAs often lead to the understatement of the government involvement in the economy and the overstatement of its financial balance, thereby lowering fiscal transparency and hiding fiscal risks. Central banks, as public corporations, perform various QFAs in many countries. I define QFAs in this case as those activities that are not directly related to the intrinsic function of central banks, whose responsibility lies in the administration of monetary policy and the provision of banking services for the government and commercial banks. In Korea, the Bank of Korea (BOK) has been an active source of QFAs. Of particular importance are the policy loans to commercial banks to promote their lending to small- and medium-sized enterprises and others. The outstanding stock of policy loans increased rapidly in the aftermath of the recent economic crisis, and stood at 7.6 trillion won (20 percent of the reserve money) at the end of 2002. Another important QFA by BOK stems from the transfer of part of its profits to the central government. The accumulated transfer during 1998-2002 amounted to 9.9 trillion won. My calculation shows that if these and other QFAs had been carried out by the government as explicit fiscal activities, the consolidated central government financial balance would have been below the actual balance by about 0.5 percent of GDP in each year since the economic crisis. It is suggested that the QFAs by BOK be reduced in coming years not only to enhance fiscal transparency but also to expand the flexibility of BOK's reserve management. Abolishing policy loans and minimizing transfers to the government would be the first step in this direction. BOK should also consider paying interest on the government deposit held in BOK.

• Asian Journal for Public Opinion Research
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• v.5 no.4
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• pp.319-345
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• 2018

Effective higher educational management in undergraduate nursing programs is an important issue from the viewpoint of stakeholders. This qualitative research aimed to examine the characteristics of nursing students and curriculum development of undergraduate nursing education from the opinions of Boromarajonani College of Nursing Saraburi, Thailand stakeholders. The population included 4 groups: 1) the alumni who have graduated within the past 5 years and currently work in primary, secondary, and tertiary care units, 2) the supervisors and colleagues of the alumni, 3) nursing lecturers, and 4) the current nursing students. The respondents who are the alumni, nursing lecturers, and current nursing student were selected using a purposive sampling, for the supervisors and colleagues were selected using snowball techniques. Semi-structured interview questions were used for data collection. Group discussions were conducted until saturation on 55 key informants. The qualitative data was analyzed using content analysis. Results showed the viewpoints of stakeholders on the characteristics of future nurse graduates were comprised of four elements: knowledge that meets standards; essential skills for self-development and lifelong learning process; good morals and professional ethics in providing nursing care; and nurse competencies in teamwork, communication, language, research, management, IT, life skills, and global literacy. The viewpoints on the development of the nursing curriculum focus on four elements: the learner, teaching and learning, course content, and instructor tasks. For learners, the admission criteria should include a minimum not only of knowledge, but also positive attitude, science, and art skills, since the nursing profession is both a science and the art of caring. Teaching and learning elements should be authentic, including exposure to real situations, an integrated network, and activities that improve nursing care. Course content was comprised of an updated curriculum, humanized nursing care, student center, theory and practice with moral integration, case-based study, critical thinking, multidisciplinary work, and love for the nursing profession. Instructor tasks are to elicit student ideas, provide opportunities to learn, support infrastructure, support technology use, and extra-curricular activities to develop the competencies of nursing students. Recommendations were that the curriculum administration should review the selection process of student candidates and instructional management to achieve expected outcomes of nursing characteristics in the future. The nurse lecturer should provide authentic and integrated instruction, decrease lecturing, cultivate a lifelong learning process, and sustain the nursing characteristics.

• KDI Journal of Economic Policy
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• v.14 no.1
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• pp.167-189
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• 1992

The most difficult problem one faces in estimating North Korea's GNP is the lack of basic national income data. In addition, there is no appropriate foreign exchange rate available to convert North Korea's GNP to dollar values. The physical indicators method is particularly useful in estimating North Korean GNP because it requires only a modest amount of data and obtains dollar GNP directly by applying a relationship between physical indicators and GNP, which is estimated from reference countries, to physical indicators of North Korea. The estimated result of North Korean GNP in 1990 is 27.1 billion dollars and per capita GNP 1,268 dollars. The trade participation ratio (Trade/GNP) implied by the GNP estimate was plausible and so was the ratio of fiscal expenditure to GNP. This paper examined the physical indicators method's logic, the quality of the North Korean data that was used in the estimation, and the plausibility of estimation result. Relatively simple data requirement, comparative ease of computation and plausible estimation results suggest that use of physical indicators method could enhance the reliability of North Korean GNP estimate.

• KDI Journal of Economic Policy
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• v.14 no.1
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• pp.121-145
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• 1992

This paper examines characteristics of time series data related to the construction investment(stationarity and time series components such as secular trend, cyclical fluctuation, seasonal variation, and random change) and surveys predictibility, fitness, and explicability of independent variables of various models to build a short-term construction investment forecasting model suitable for current economic circumstances. Unit root test, autocorrelation coefficient and spectral density function analysis show that related time series data do not have unit roots, fluctuate cyclically, and are largely explicated by lagged variables. Moreover it is very important for the short-term construction investment forecasting to grasp time lag relation between construction investment series and leading indicators such as building construction permits and value of construction orders received. In chapter 3, we explicate 7 forecasting models; Univariate time series model (ARIMA and multiplicative linear trend model), multivariate time series model using leading indicators (1st order autoregressive model, vector autoregressive model and error correction model) and multivariate time series model using National Accounts data (simple reduced form model disconnected from simultaneous macroeconomic model and VAR model). These models are examined by 4 statistical tools that are average absolute error, root mean square error, adjusted coefficient of determination, and Durbin-Watson statistic. This analysis proves two facts. First, multivariate models are more suitable than univariate models in the point that forecasting error of multivariate models tend to decrease in contrast to the case of latter. Second, VAR model is superior than any other multivariate models; average absolute prediction error and root mean square error of VAR model are quitely low and adjusted coefficient of determination is higher. This conclusion is reasonable when we consider current construction investment has sustained overheating growth more than secular trend.

• KDI Journal of Economic Policy
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• v.14 no.1
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• pp.61-87
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• 1992

Reducing the level of greenhouse gas emissions is necessary to mitigate global warming. One of the most feasible methods to reduce emissions would be to conserve energy and substitute fossil fuels. Yet reducing emissions entails huge financial costs, so it is advisable to employ cost-effective economic instruments such as a carbon tax or tradeable emissions permits. Assuming that the proper economic tools will be used in the future, we calculated the optimal level of emissions reduction for Korea. We applied to our cost-benefit analysis Nordhaus' scenario regarding the economic damage from a $3^{\circ}C$ rise in global temperatures, which is the calculated result when the greenhouse gas level doubles. The result of our analysis based on the 1990 data indicates that the optimal level of emissions reduction ranges from 2% to 15 % of current emissions depending on the value of damage parameters. We also found that the amount of emissions must be reduced will increase if action is postponed, when the development of climate engineering technology or more efficient use of energy is expected. In addition, we discussed the advantages and disadvantages of the economic instruments available to implement emissions reduction. Tradeable permits and carbon tax are equivalent in their cost-effectiveness, but have different implications in practice.

• KDI Journal of Economic Policy
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• v.14 no.1
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• pp.191-212
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• 1992

This paper discusses the role of money in the process of capital accumulation where financial markets are impeded by contract enforcement problems in the context of overlapping generations framework. In particular, in less developed countries (LDCs) creditors may know little about the repayment capability of potential debtors due to incomplete information so that financial instruments other than money may not acceptable to them. In this paper the impediments to the operation of the private finanical markets are explicitly modelled. We argue that creditors cannot observe actual investment decisions made by the potential borrowers, and as a result, loan contracts may not be fully enforceable. Therefore, a laissez-faire regime may fail to provide the economy with the appropriate financial instruments. Under these circumstances, we introduce a government operated discount window (DW) that acts as an open market buyer of private debt. This theoretical structure represents the practice of governments of many LDCs to provide loans (typically at subsidized interest rates) to preferred borrowers either directly or indirectly through the commercial banking system. It is shown that the DW can substantially overcome impediments to trade which are caused by the credit market failure. An appropriate supply of the DW loan enables producers to purchase the resources they cannot obtain through direct transactions in the credit market. This result obtains even if the DW is subject to the same enforcement constraint that is responsible for the market failure. Thus, the DW intervention implies higher investment and output. However, the operation of the DW may cause inflation. Furthermore, the provision of cheap loans through the DW results in a worse income distribution. Therefore, there is room for welfare enhancing schemes that utilize the higher output to develop. We demonstrate that adequate lump sum taxes-cum-transfers along with the operation of the DW can support an allocation that is Pareto superior to the laissez-faire equilibrium allocation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.4
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• pp.290-296
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• 2018

In this study, the cold test and the numerical analysis were carried out according to the shape parameters of the test model in order to confirm the operation range of high altitude environment simulation test facility for the supersonic vehicle. The blockage ratio, angle and length ratio were considered as the design parameters. The blockage rate is expected to be limited in the region of more than 40% due to the normal shock and expansion fan. It was confirmed that the angle of model should be selected at the size of 45 degrees or less due to the influence of the strong shock wave. There was no difference in performance between the lengths of 8 times the model diameter. Finally, we obtained the performance database according to the shape parameters of the conical test model and confirmed the operable range of the semi-freejet type high altitude environment simulation test facility.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.3
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• pp.643-653
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• 2018

Xamarin is a representative cross-platform development framework that allows developers to write mobile apps in C# for multiple mobile platforms, such as Android, iOS, or Windows Phone. Using Xamarin, mobile app developers can reuse existing C# code and share significant code across multiple platforms, reducing development time and maintenance costs. Meanwhile, malware authors can also use Xamarin to spread malicious apps on more platforms, minimizing the time and cost of malicious app creation. In order to cope with this problem, it is necessary to analyze and detect malware written with Xamarin. However, little studies have been conducted on static analysis methods of the apps written in Xamarin. In this paper, we examine the structure of Android apps written with Xamarin and propose a static analysis technique for the apps. We also demonstrate how to statically reverse-engineer apps that have been transformed using code obfuscation. Because the Android apps written with Xamarin consists of Java bytecode, C# based DLL libraries, and C/C++ based native libraries, we have studied static reverse engineering techniques for these different types of code.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.2
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• pp.35-39
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• 2018

In order to improve the coupling efficiency, a collimator lens that collects the light emitted from the laser diode at a wide angle to the core of the optical fiber is essential. Glass mold method using a mold is widely used as a collimator lens currently used. Although this method is inexpensive to produce, it is difficult to form precisely and quality problems such as spherical aberration. In this study, the precision of surface processing was improved by replacing the existing glass mold method with the semiconductor process, and the material of the lens was changed to silicon suitable for the semiconductor process. The semiconductor process consists of a photolithography process using PR and a dry etching process using plasma. The optical coupling efficiency was measured using an ultra-precision alignment system for the evaluation of the optical characteristics of the silicon lens. As a result, the optical coupling efficiency was 50% when the lens diameter was $220{\mu}m$, and the optical coupling property was 5% or less with respect to the maximum optical coupling efficiency in the lens diameter range of $210-240{\mu}m$.