• Journal of Korean Institute of Industrial Engineers
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• v.12 no.2
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• pp.89-99
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• 1986

The study attempts to estimate and evaluate the rates of return on graduate degree holders who major in science and engineering. The model of this study adopts the rate of return method considering unemployment as well as mortality rate. The data are collected by questionnaires and interviews. The results show that the social rate of return(SROR) of bachelors is lower than the rate of return on investment in physical capital which is assumed as a decision criterion of public investment in Korea, but the SROR of Ph.D. holders is balanced. The results also show that the private rates of return (PROR) of all the levels in postgraduate science and engineering education are higher than the private discount rate which is a decision criterion of private investment in Korea. It also indicates that the PROR on investment in graduate education is not likely higher than the SROR because an individual bears high share of the educational costs.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2004.05a
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• pp.77-97
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• 2004

In this paper we: (1) analyze the relationship among public R&D investment, private R&D investment, and GDP by employing the Granger causality test; (2) examine if there is any country-specific pattern in the relationship by testing the cases of Korea, the U.S. and Japan. We found some common results for the above countries as follows: (i) GDP causes Public R&D, not vice versa; (ii) Private R&D causes GDP; and (iii) Public R&D does not cause Private R&D. For the bivariate model of GDP and total R&D, the results show the existence of one-way causality running from total R&D to GDP for both U.S, and Japan. We also found bidirectional causal relationship between GDP and total R&D for Korea, which could be interpreted as a typical pattern for newly industrialized countries.

• Journal of Construction Engineering and Project Management
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• v.3 no.2
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• pp.35-48
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• 2013

Weak competencies in urban local bodies (ULBs) for implementing public private partnership (PPP) projects has been recognized as a major hurdle in uptake of PPP model in India. In this context, a questionnaire survey was conducted to evaluate perception of urban PPP experts and ULB representatives on three aspects related to competency development, including, critical competencies for implementing urban PPP projects, approaches for competency development in ULBs and constraints faced by ULBs in development of competencies. The five critical competencies identified are project identification, project conceptualization, transaction design, PPP process management and contract management. The approach of training programs for municipal staff and elected representatives, and capacity building oriented technical assistance for implementing urban PPP projects have been preferred by survey respondents for competency development. The frequent transfer of municipal decision makers and low motivation among municipal staff have been identified as the most significant constraints for development of competencies.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.4
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• pp.25-37
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• 2015

The early studies indicated that the firm with monopoly power is likely to engage in X-inefficiency such as a managerial slack. The reflection of the X-inefficiency theory has led to the issue that the public sector may be more inefficient than the private sector. In Korea like other many countries the electricity gas water service which can be considered as natural monopoly have been provided mostly by the public sector. In order to provide the empirical evidence to the argument that the public sector may be more inefficient than the private sector this paper estimated the four types of Solow residual which is called the total factor productivity in the electricity gas water service industry with the associated empirical model and compared its productivity with one in the manufacturing industry. The empirical results do not support the argument that the public sector may be more inefficient or less productive than the private sector.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.2
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• pp.428-439
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• 2011

The main challenge in building efficient broadcast systems is to encrypt messages with short ciphertexts. In this paper, we present a new construction based on the identity. Our construction contains the desirable features, such as constant size ciphertexts and private keys, short public keys and not fixing the total number of possible users in the setup. In addition, the proposed scheme achieves the full security which is stronger than the selective-identity security. Furthermore we show that the proof of security does not rely on the random oracles. To the best our knowledge, it is the first efficient scheme that is full security and achieves constant size ciphertexts and private keys which solve the trade-off between the ciphertext size and the private key size.

• ETRI Journal
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• v.40 no.6
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• pp.813-823
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• 2018

In existing mobile computing environments, users need to choose between their privacy and the services that they can receive from an application. However, existing mobile platforms do not allow users to perform such trade-offs in a fine-grained manner. In this study, we investigate whether users can effectively make utility-privacy trade-offs when they are provided with a multilevel privacy control method that allows them to recognize the different quality of service that they will receive from an application by limiting the disclosure of their private information in multiple levels. We designed a research model to observe users' utility-privacy trade-offs in accordance with the privacy control methods and other factors such as the trustworthiness of an application, quality level of private information, and users' privacy preferences. We conducted a user survey with 516 participants and found that, compared with the existing binary privacy controls, both the service utility and the privacy protection levels were significantly increased when the users used the multilevel privacy control method.

• International journal of advanced smart convergence
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• v.10 no.2
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• pp.10-14
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• 2021

Today people adopt various contents from their mobile devices which lead to numerous platforms. As technology of 5G, IOT, and smart phone develops, the number of people who create, edit, collect, and share their own videos, photos, and articles continues to increase. As more contents are shared online, the numbers of data being stolen continue to increase too. To prevent these cases, an authentication method is needed to encrypt the content and prove it as its own content. In the report, we propose a few methods to secure various misused content with secondary security. A unique private key is designed when people create new contents through sending photos or videos to platforms. The primary security is to encrypt the "Private Key" with a public key algorithm, making its data-specific "Timeset" that doesn't allow third-party users to enter. For the secondary security, we propose to use Message Authentication Codes(MACs) to certify that we have produced the content.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.124-131
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• 2011

Public infrastructure is crucial to promote and sustain a sustainable economic growth and a health community. A large amount of capital investment is generally required in infrastructure projects that motivate the involvement of the private sector in the delivery process. Various relationship-based procurement methods have been attempted to maximize value-for-money. In this paper, the problems and challenges that relationship-based procurement methods have been facing are explored. A particular focus is placed on the challenges for the public-private partnership (PPP) model. Possible strategies for adapting the PPP models in the post-Global Financial Crisis era are proposed and discussed. In addition, the challenges facing alliancing, which is one of the other important relationship-based procurement methods, are also examined. Views on infrastructure procurement in the future were sought from industry professionals via interviews and are reported in this paper as well.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.360-365
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• 2016

The purpose of this study is to provide the basic information for the early enforcement and extension of the improvement project of management scale of private forest land by understanding the characteristics of forest owners, who have an influence on the participation of the project as one of the private forest management vitalization plans. To achieve this goal, a questionnaire survey targeting 373 forest owners was conducted and analyzed by Binary-Logistic Regression. The variables for binary-logistic regression included gender, age, academic ability, occupation, income, residence, purpose of forest ownership, and status of cooperative membership. As a result of the analysis, 267 forest owners (71.6%) of total 373 forest owners have the intention to participate in the scaling project for private forest management. The rest of forest owners (106 forest owners, 28.4%) would not be willing to participate in the project. As a result of binary-logistic regression, the most important variables, which have an impact on the participation of private forest management scale improvement project, are age, job and forest own purpose.

• Convergence Security Journal
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• v.15 no.6_2
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• pp.99-106
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• 2015

The purpose of this study was to explore the direction in applying platform business model to the site to facilitate the growth of a private security guard service according to the development phase of economy, The directions of platform business application to be suggested through the study method are as follows. First, ensuring publicness. It should be able to integrate the government's and private sector's ability to collect and impart information. Second, securing self-regulation. Self-regulation should be guaranteed in the limit not to abuse or misuse others' information in re-producing and using information on private safe management and public order. Third, ensuring access. Past safety management has been controlled by public order power such as nation, military and police power, but access should be made to be convenient between suppliers and demanders. Fourth, securing profitability. In conclusion, those supplying and consuming private security guard service should be able to get their wanted value and share economic profits.