• Title/Summary/Keyword: Private and Public Key

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PROMISE: A QR Code PROjection Matrix Based Framework for Information Hiding Using Image SEgmentation

  • Yixiang Fang;Kai Tu;Kai Wu;Yi Peng;Yunqing Shi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.2
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    • pp.471-485
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    • 2023
  • As data sharing increases explosively, such information encoded in QR code is completely public as private messages are not securely protected. This paper proposes a new 'PROMISE' framework for hiding information based on the QR code projection matrix by using image segmentation without modifying the essential QR code characteristics. Projection matrix mapping, matrix scrambling, fusion image segmentation and steganography with SEL(secret embedding logic) are part of the PROMISE framework. The QR code could be mapped to determine the segmentation site of the fusion image as a binary information matrix. To further protect the site information, matrix scrambling could be adopted after the mapping phase. Image segmentation is then performed on the fusion image and the SEL module is applied to embed the secret message into the fusion image. Matrix transformation and SEL parameters should be uploaded to the server as the secret key for authorized users to decode the private message. And it was possible to further obtain the private message hidden by the framework we proposed. Experimental findings show that when compared to some traditional information hiding methods, better anti-detection performance, greater secret key space and lower complexity could be obtained in our work.

A Study on Risk Sharing of PPI Project Demand Risk (민간투자사업 수요위험 분담 방식에 관한 연구)

  • Shin, Sung-Hwan
    • Korean Journal of Construction Engineering and Management
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    • v.13 no.2
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    • pp.102-109
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    • 2012
  • One of key success factors in PPI(Public Private Investment) is the structure of risk sharing between the public and the private, and the determination mechanism of fair return to private participants relative to the risk that private participants undertake. In Korea, two basic types of PPI exist. One is BTO and the other is BTL. In BTO, most risks are taken by the private whereas the opposite is the case in BTL. No intermediate form exists. As a result, BTO type projects had difficulty in attracting private participants because of the excessive risks. In this study, one intermediate form is studied where demand risk is shared between the public and the private. In the setting where the public authority takes all the project revenues and then pays ladder type payments to private participants depending upon the level of project revenues, appropriate level of fixed payments is endogenously derived using the real option pricing model. From the fixed payments, expected investment returns are calculated based upon a certain distributional assumption. The results of this study is expected to help introducing diverse forms of PPI in Korea.

Optical Implementation of Asymmetric Cryptosystem Combined with D-H Secret Key Sharing and Triple DES

  • Jeon, Seok Hee;Gil, Sang Keun
    • Journal of the Optical Society of Korea
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    • v.19 no.6
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    • pp.592-603
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    • 2015
  • In this paper, an optical implementation of a novel asymmetrical cryptosystem combined with D-H secret key sharing and triple DES is proposed. The proposed optical cryptosystem is realized by performing free-space interconnected optical logic operations such as AND, OR and XOR which are implemented in Mach-Zehnder type interferometer architecture. The advantage of the proposed optical architecture provides dual outputs simultaneously, and the encryption optical setup can be used as decryption optical setup only by changing the inputs of SLMs. The proposed cryptosystem can provide higher security strength than the conventional electronic algorithm, because the proposed method uses 2-D array data, which can increase the key length surprisingly and uses 3DES algorithm, which protects against “meet in the middle” attacks. Another advantage of the proposed asymmetrical cryptosystem is that it is free to change the user’s two private random numbers in generating the public keys at any time. Numerical simulation and performance analysis verify that the proposed asymmetric cryptosystem is effective and robust against attacks for the asymmetrical cipher system.

Secure Asymmetric Watermarking Based on Correlation Detection (상관도 검출기반의 안전한 비대칭 워터마킹)

  • Li De;Kim JongWeon;Choi JongUk
    • The KIPS Transactions:PartC
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    • v.12C no.3 s.99
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    • pp.379-386
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    • 2005
  • Traditional watermarking technologies are symmetric method which embedding and detection keys are same. Although the symmetric watermarking method is easy to detect the watermark, has method has weakness against to malicious attacks to remove or modify the watermark information when the symmetric key is disclosure. Recently, the asymmetric watermarking method that has different keys to embed and detect is watched several researchers as a next generation watermarking technology. In this paper, we have expanded search space of secret key using the solution set of linear simultaneous equations. Secret key is generated by secure linear transformation method to prevent of guessing secret key from public key, and the correlation value between secret key and public key is high. At the results, the multi bits information can be embedded and high correlation value was detected after JPEG compression.

Characteristics of Spatial Environment in Psychiatric Wards through the Analysis by Patient's Preferred Healing Environment in Observational Ward Structure Dividing Staff Area and Patient Area (정신요양 병동에서의 관리영역과 환자의 요양 공간영역의 관찰적 시선에 따른 병동구조와 요양 공간환경의 특성에 관한 연구)

  • Joo, Yongsun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.27 no.2
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    • pp.57-64
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    • 2021
  • Purpose: The relationship between the staff area and the patient's private area is the key factor in designing the structure and the environmental characteristics of ward spaces in a psychiatric hospital. Recent research has found that for the purpose of treatment and securing privacy, psychiatric patients need to be in an open space of relief rather than closed confined environment and under the watch of nursing staffs. Methods: A survey at three kinds of wards in a private psychiatric hospital in Japan was conducted in October 2002. These wards include an acute ward, a psychiatric convalescence ward, and a stress care ward. All three kinds of wards have the same structure. At each ward, spatial preferences of the 145 psychiatric inpatients were surveyed and data concerning the patient's diagnostic category, symptoms, and activities of daily living were recorded. Results: The patients in the stress care ward prefer to stay in private spaces than public spaces. On the other hand, in the acute ward the patients seem to have a preference between managed public spaces where are monitored by nursing staffs and their private rooms where the nurse station is close. In addition, the patients in the psychiatric convalescence ward spend most of their time in the public space, such as the hallways or the day room. Implications: Base on this research, the spaces at the acute ward that could be monitored by the nursing station serves effectively as a safety space for patients was concluded. However, in the stress care ward, the patients may perceive the monitoring by the nursing staff as interruption or nuisance to their relaxation. In order to design an ideal healing environment for psychiatric patients in psychiatric ward, it is important to consider how environmental characteristics of space affect the environmental sense of patients in each ward.

Development of China's water public-private partnership and the growth of Chinese water players (중국 물산업 민관협력사업(PPP) 발전과정과 중국 물기업의 성장요인 분석에 관한 연구)

  • Oh, Jihye
    • Journal of Korea Water Resources Association
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    • v.55 no.3
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    • pp.217-227
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    • 2022
  • Since China adopted Public-Private Partnerships (PPPs) in the water sector in the early 1990s, PPPs have played a key role in improving infrastructure development in China. As the Chinese water market became one of the most enormous and potential existing in the world, once a water player settles down in the market, the company tends to be the world-leading water player on the basis of the number of people served from water infrastructure. Unlike the early PPP period overwhelmed by several water transnational corporations, local water players began to dominate the domestic market and have recently expanded their influence overseas. The Chinese government has continuously intervened to promote private sector participation of local water players in the PPP development process in legal and institutional aspects. Thus this article examined the development of water PPPs in China and analyzed the successful elements of local water players' growth related to the government policy.

The Performance and Implication of A Market-oriented Health Care System in United States (미국 시장지향 의료체계의 성과와 시사점)

  • Lee, Key-Hyo
    • Korea Journal of Hospital Management
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    • v.9 no.1
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    • pp.1-21
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    • 2004
  • The United States has a unique health care system, which is unlikely any other health care systems in the world. The major part of basic functional components of the system -financing, insurance, delivery, and payment- is in private hands. A market-oriented economy invites the participation of numerous private entities that are interested in carrying out the key functions of health systems. Due to this central feature, U.S.health care is not delivered through a network of interrelated components designed to work together coherently. For lack of standardization, the various components of the system fit together only loosely. The involvement of numerous players in the key functions leads to duplication, overlap, inadequacy, inconsistency, and waste, which add to the complexity and also make the system inefficient. Hence, cost containment remains an elusive goals. Moreover, the system falls short of delivering equitable services to all americans, though consumption of health care services is the largest in the world. On the other hand, United States leads the world in the latest and the best in medical technology, medical training, and research. It offers some of the most sophisticated institutions, products, and processes of health care delivery. This article discuss the characteristic features of the U.S. health care system. and its performance, trying to seek its implication on Korean health care system.

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The First Global Management Plan for the Urban Landscape Restructure in Tokyo

  • Iglesias, Fernando;Shinji, Isoya
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • no.1
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    • pp.176-182
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    • 2001
  • The case for study in this paper is the Main Plan and Management for the Fukutoshin; the restructure of Nishi Shinjuku, This plan was first outlines in 1960, and includes a vast area of 96 ha for redevelopment. It aims to create a totally new center in the city. This was the first case in Japan, and in the world of a plan of these magnitudes. involving urban landscape restructuring from three points: Landscape (open spaces for public use: the Shinjuku Central Park and the surrounding area of the buildings), transport and commercial building developments. The Landscape plan for the green areas was decided in a way to compensate the population of the area and the visitors. As a rule, high-rise building constructions are placed each one in single lots and are surrounded by open spaces and greenery. Pedestrain areas are widened and also connected by bridges in a way to allow free circulation, and interconnection between the constructions and the green areas. Another important factor is the role that Private Corporation, and public interest plays. Joining these two forces has allowed the concretization of this project. This interpolation between public and private roles was an innovation in Japan, and it also the key for the concretion of the project. The historical review of the process and management of this project help us to put into perspective the introduction of new concepts and ideas, which were not related at that time to traditional Japanese Landscaping. Furthermore we are better able to understand the substantial increase in the percentage of land dedicated to green areas in contrast to the typical standards of Japanese cities.

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NHS Reforms and Healthcare Market in the United Kingdom (영국의 NHS 개혁 및 의료시장 동향에 관한 연구)

  • Nam, Eun-Woo;Chun, Ki-Young
    • Korea Journal of Hospital Management
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    • v.8 no.4
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    • pp.1-25
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    • 2003
  • The wave of globalisation initiated by marketisation has increasingly penetrated into all sectors across the world, accordingly, the health & hospital service sector could not be made no escapes, and it currently faces the order of more marketised competition more than ever. Traditionally, the characteristic of the hospital services in the UK has considered as a model of social provision by government. However, contrary to our knowledge, the sphere of the hospital service in the UK has already been immersed in by the marketisation, in which the private actors have been embedded in order to tweak the activities of the hospital service with in the European Union. As the methodology of this research, the qualitative analysis, namely the interview with some doctors in Surgery, NHS Trusts staffs and relevant specialists in has been performed on April to May, 2003. And on the other hand, the various documents related to its service have been analysed. Thus, this paper will review the characteristics of the health service sector in the UK. In doing so, it will illuminate what would be the structural factors derived from its existing system, as a result, it will shed light on how the UK government makes an effort to resolve the problematic situation by reviewing the policy direction of Foundation Hospital proposed recently. In the next stage, it will analyse how all elements consist of the hospital management in the UK has been adjusted and be likely to be changed within Europe. More specifically focuses on how the private hospital service has been managed and related with the activities of its public hospital service-NHS Trusts. Also, under the circumstance, what private health insurance companies function will be studied. In conclusion, it will be concluded that what will be the implication of Korean hospital service market so as to correspond to globally open market by WTO. Now the UK health service system has faced a turning point of becoming more health care market internally and externally pressed by global and regional factors. Thus it is meaningful to scrutinize how a key part of social provision in the health care market system tends to adjust to globally marketised regulation.

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A Human-Scaled Future for Dense Development

  • Harbour, Ivan
    • International Journal of High-Rise Buildings
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    • v.7 no.2
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    • pp.141-143
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    • 2018
  • Critics of height argue that it de-humanizes our cities. Yet a critical mass is a necessity for vibrant city life, and height is a key contributor. If we can overcome the environmental impacts and technicalities of building tall and dense, our cities' streets can thrive and prosper. To make this happen, we must move towards working together to share resources, so we can ensure the continuity of the public realm. We already have the tools to do this; the challenge lies in the coordination of the public and private institutions that govern urban space. District heating and cooling systems; shared logistics spaces; care, responsibility and ownership of the public realm between buildings; seamless connectivity between modes of transport; creative combinations of shelter and seating, and the placement of buildings so that they are not overbearing to the streets around them - these attributes can be found in many places, though rarely all at once. This paper looks at the development of the city and offers Barangaroo South, Sydney, which addresses all these aspects, as a potential template for future city planning.