• 정보보호학회논문지
• /
• 제16권2호
• /
• pp.113-119
• /
• 2006

화상을 이용한 심층암호는 화상에 숨긴 비밀 메시지를 전송하기 위한 비밀 통신의 한 방법이다. 디지털 화상에 비밀 메시지를 은닉시키기 위해서 엄폐화상은 은닉 알고리즘에 의해 변경이 되며, 그 결과 은닉화상이 생성된다. 송신자는 의미 없는 일반적인 엄폐화상에 비밀 메시지를 숨긴 은닉화상을 수신자에게 전송한다. 본 논문에서는 화상의 연속 두 화소간의 차분과 비밀 양자화 범위를 이용하여 비밀 메시지를 은닉하는 공간 영역 기반의 심층암호 기법을 제안한다. 특히, 제안 방식은 삽입용량을 증가시키기 위해 모듈러 연산을 이용한다. 제안 방식은 모듈러 연산을 수행함으로써 기존의 관련 방식[6]보다 비밀 메시지의 삽입용량을 평균 60% 정도 더 증가시킬 수 있었다.

• 한국항만경제학회지
• /
• 제20권1호
• /
• pp.57-77
• /
• 2004

The meaning of seaport has always been translated into something concerned with nation-wide goals and viewpoints, which used to be in developing country. The time developing countries have tried to be in pursuit of their economic development, one of important sectors is SOC investment that is needed into huge capital input which they couldn't easily afford to it. Another one which we have to mention in terms of seaport at contemporary maritime matters is privatization of port, that is strongly connected with efficiency to achieve port productivity. All these factors can produce high quality of service, and port co-operation and diversification of their business areas, etc. Therefore we then have to think of private port management companies such as P&O Ports, Hutchison Whampoa in HK, etc. in order to provide better port service to the customers, and they can also get involved into capital port investment as well. This kind of concept already comes from Denholm Ship management companies in shipping. So, it is necessary for us to look into port management company in our side, which means, we have to be involved into such a business to invest and manage foreign ports as well as our ports. Then, port competitiveness will follow in our ports.

• 한국어학
• /
• 제65권
• /
• pp.295-320
• /
• 2014

The idiom is listed in the lexicon, because it's meaning cannot be inferred from it's constituents. And the idiom is a single semantic unit. Thus the idiom is inserted to the syntax in the quality of a word. But the idiom is not always inserted to the syntax as a word. In the process generating the sentence, we can recognize the categorial property of the idiom that it is formally equal to the syntactic phrase. Then each of the constituents of the idiom can be inserted to the syntax. This is why the syntactic operation(as modification, topicalization, relativization, etc) can be applied to the constituent of the idiom. In this respect the idiom is a flexible construction as the listeme of a lexicon. The flexible property of the idiom is related to the dynamicity of a lexicon. The formal or semantic transformation of the idiom is the good example to show the dynamicity of a lexicon.

• 농업과학연구
• /
• 제39권2호
• /
• pp.279-289
• /
• 2012

This study was conducted to survey and diagnose operation status of the agricultural machinery rental service, analyse and compare operational efficiency among 82 city and county ATDEC (agricultural technology development and extension center) using the DEA (Data Envelopment Analysis) method, and recommend future direction, for improvement of the business. Input variables were invested budget and labor, and output variable was rental return. Percentages of return to investment on the rental service were calculated as 68.3% and 63.9% when analyzed with CCR (Charnes, Cooper and Rhodes) and BCC (Banker, Charnes and Cooper) models, respectively, indicating inefficiency of the service operation. Increase of rental charge would increase efficiency by 63.9~68.3% depending on models, and decrease of financial and labor investment would improve the efficiency by about 11.3%. Technical efficiency would be more important than scale efficiency, therefore adjustment of over-invested budget and labor needed to be made together with increase of rental charge to improve the operation. Among the ATDECs providing the rental service, 6 (7.3%), 43 (52.4%), and 33 (40.2%) were in state of CRS (constant return to scale), IRS (increasing return to scale), and DRS (decreasing return to scale), respectively. These indicated public aspects of the rental system, over-investment, lack of output component for input component, meaning that scale income would be increased by qualitative expand of rental charge. Efficiency analysis of the rental system by region showed that efficient ATDECs to be benchmarked by others were in the order of DMU-70, DMU-54, DMU-29, DMU-5, DMU-22, DMU-2, and DMU-61. More comprehensive and extensive survey and analyses would be necessary in the future.

• 건축역사연구
• /
• 제30권1호
• /
• pp.19-32
• /
• 2021

The markets are the basic urban facilities for maintaining daily life. Although the urban structure changed rapidly and the population quickly concentrated in the city, the markets remained traditional and backward. To solve various problems in the small excess markets, the Seoul Metropolitan Government had pushed ahead with the market modernization plan since 1967. The purpose of this study is to analyze the process of establishing the market modernization plan and the progress of this project, and to identify the historical meaning of this plan. The results of this study as follows; The market modernization plan aimed to modernize market operation system as well as buildings, and the Government was able to achieve its first goal by enforcing the construction of high-rise buildings, as the markets were newly built with the relatively large scaled fireproof structures. Despite its various limitations, these markets were also regarded as the model of the modern market.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제47권1호
• /
• pp.61-74
• /
• 2008

The objective of this research is to verify the effect after development and application of a program for advance of number sense. This program presents an opportunity to explore suitable ways for the characteristics of problems by clarifying the meaning of number and operation through various thought processes, not focused on algorithm. To fulfill the objectives I developed the program for advance of number sense, and verify the effect on the improvement of number sense after applying to the developed program. As a result, it was confirm that this program was helpful to the improvement of the students' mathematical aptitude which resulted in a positive change in their attitude.

• 한국안전학회지
• /
• 제31권5호
• /
• pp.171-176
• /
• 2016

The railway safety sign, which is a part of railway signal system, is installed at the lineside to inform a train driver the position, direction or condition concerning the train operation by its shapes, colors or symbols. The sign in the existed line of South Korea has low-level of visibility and legibility, so that it is difficult for the drivers to understand the meaning of a sign enough by just seeing its letters or pictogram. This paper is aimed at reviewing the design problems of the sign in existed line and developing the design to enhance its visibility and legibility and verifying its effectiveness.

• 대한한의학원전학회지
• /
• 제22권4호
• /
• pp.217-220
• /
• 2009

In "Hwangjenaegyeong(黃帝內經)", the name of blood vessels is closely related to images of the river, and the word for blood vessel contains the following meaning, such as blood vessel, blood wind as well as blood stasis and so on. In a physiological perspective, the unobstructed blood vessel and normal operation blood are important symbols of health, for blood is the basis for human survival, physical activity and mental activity. In pathology, the external cold, excessive seven emotions and a biased diet can cause many kinds of abnormalities of the blood vessels, which can in turn become causes for a variety of diseases. The theory of blood vessels in "Hwangjenaegyeong" can provide guidance for diagnosis and treatment of cardiovascular diseases in practice.

• Corrosion Science and Technology
• /
• 제18권2호
• /
• pp.49-54
• /
• 2019

The purpose of this paper is to present failure analysis, of the heat exchanger tube in a district heating system. SS304 stainless steel is used, as material for the heat exchanger tube. The heat exchanger operates in a soft water environment containing a small amount of chloride ions, and regularly repeats operation and standstill period. This causes concentration of chloride ions on the outer surface of the tube, as well as repeat of thermal expansion, and shrinkage of the tube. As a result of microscopic examination, cracks showed transgranular as well as branched propagation, and many pits were present, at the initiation point of each crack. Energy disperstive spectroscopy analysis showed Fe and O peak, as well as Cl peak, meaning that cracks were affected by Cl ion. Failure of the tube was caused by chloride-induced stress corrosion cracking by thermal stress, high temperature, and localized enrichment of chloride ions.

• 교육시설
• /
• 제17권2호
• /
• pp.23-30
• /
• 2010

At present, the necessity of new design guidelines, evaluation and operation system for school facilities are on the rise according to re-edition of school curriculum in Korea. Moreover, it is necessary to procedure of the design, an institutional device and an ex post facto evaluation system for school facilities as a public building with the space planning that is suitable for various situations, which are able to collect users' various demands and opinions. Under the present situation, England has introduced and operated DQI system for the users' participation design of its. The present study will derive the meaning DQI system of England and how to operate it, and percuss the possibility of the application of design procedure of the education facilities in Korea.