• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.355-362
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• 2016

The pipe material is selected according to the physical and chemical properties of the fluid flowing within it. Because the fluid used in fire extinguish systems is water, the various foreign substances dissolved in it cause scale to form on the pipe wall and accelerate the corrosion and aging of the pipe itself. This results in an increase in the friction loss and eventually degrades the efficiency of the pump. The use of CPVC (Chlorinated Poly-Vinyl Chloride) pipes was confirmed to reduce the friction loss compared to conventional steel pipes in the design and construction stages. The friction loss was found to be 76.64MPa with a C-value of 120 for the steel pipe and 50.72 MPa with a C-value of 150 for the CPVC pipe in an actual apartment construction environment. It was confirmed that the friction loss was improved by about 34% when using the CPVC pipe. When the steel and CPVC pipes were employed in the construction, the construction costs were 1,585,158 and 931,842 won, respectively. Therefore, it was shown that the construction cost was reduced by about 41%. We investigated the safety of the fire extinguishing system and the improvement in the economic performance due to the reduction in the total installed capacity by studying practical applications in the field.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.9
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• pp.429-436
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• 2017

Unmanned Aerial Vehicles (UAV) that are piloted without human pilots can be commanded remotely via frequencies or perform pre-inputted missions. UAVs have been mainly used for military purposes, but due to the development of ICT technology, they are now widely used in the private sector. Teal Group's 2014 World UAV Forecast predicts that the UAV market will grow by 10% annually over the next decade, reaching $ 12.5 billion by 2023. However, because UAVs are primarily remotely controlled, if a malicious user accesses a remotely controlled UAV, it could seriously infringe privacy and cause financial loss or even loss of life. To solve this problem, a secure channel must be established through mutual authentication between the UAV and the control center. However, existing security techniques require a lot of computing resources and power, and because communication distances, infrastructure, and data flow are different from UAV networks, it is unsuitable for application in UAV environments. To resolve this problem, the study presents a lightweight UAV authentication method based on Physical Unclonable Functions (PUFs) that requires less computing resources in the ground Control and Non-Payload Communication (CNPC) environment, where recently, technology standardization is actively under progress.

• Journal of Aerospace System Engineering
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• v.14 no.1
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• pp.28-35
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• 2020

This paper presents the design improvements made for the crack which is in the mounting structure of the mechanical structure of rotary wing aircraft. The doubler added to the mounting structure of rotary wing aircraft was designed and manufactured based on the load at the development stage, and a crack was found in the surface of doubler at a certain point during the operation of the aircraft. To identify the cause of the crack, the initial deformation of the structure, which may occur as a result of fastening condition, was considered and the dynamic analysis of the natural frequency of the structure comparing to the blade passing frequency of the aircraft were additionally reviewed. As a result of this study, a shim was added to remove the physical gap of the fastening area, and a doubler with thickened reinforcement was installed. The increase of structural strength is shown by reviewing the results of dynamic analysis for the structural verification of the improved design, and the fatigue evaluation complied to the requirement of the aircraft lifetime.

• Journal of Sasang Constitutional Medicine
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• v.11 no.1
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• pp.79-102
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• 1999

1. Purpose : This studied Cold and Heat syndromes about Four-form Constitutional Physicalogy. It is for help the comprehension, diagnosis and treatment of physicalogy and pathology about each type. 2. Method : I studied the conception of Cold and Heat sydrome in the existing Oriental Medicine before Constitutinal Medicine, through a few symptoms(constipation, diarrhea, sweat, urine, vomiting) and physicalogy, pathology in Dongyi-Soose-Bowon. 3. Results & Conclusion : In the viewpoint of Pathological Disease and a Chapter Name, Shaoyin has the Exterior-Febrile and Interior-Cold Disease, as the constitutional primary cause of the Interior-Cold Disease, Shaoyang has the Exterior-Cold and Interior-Febrile Disease, as the Interior-Febrile Disease, accoreing to the process of the promote incomings and outgoings of food stuffs of the Spleen and Kidney. By the way, Taiyin is classified into 'One who had had the Cold Disease Primarily and the Febrile', Taiyang has the nature of 'No Cold, No Heat' that is not tendency to The Cold or Heat sydromes, according to promote the respiration of air and fluid of the Liver and Lung. In the viewpoint of a few symptoms(constipation, diarrhea, sweat, urine, vomiting), we are known that cold and heat connception of the each symptome is fixed, according to nature of cold and heat in each type. These express the methood of 'constitutional demonstration'.

• Journal of Korean Academy of Nursing
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• v.7 no.2
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• pp.1-10
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• 1977

Personalized Patient centered nursing care is increasingly difficult to achieve despite the fact that it remains one of our consistent goals. So, we must find away to individualized nursing care. One means, to achieve this is by use of the nursing history form, which has been developed to help the nurse make maximum use of her limited time with the patient, by obtaining systematically the information needed to plan his nursing care. The nursing history form can be used to collect data about individual nursing needs but also it lends itself to the collection of epidemiological data relevant to the needs of patient population. So this study was undertaken in an attempt to describe the general characteristics of the population studied, to find out their perceptions and expectations related to their illness and hospitalization, to find out specific basic needs and to examine the relationship between the patients nursing needs and demographic characteristics through the responses to the nursing history questions. The study population defined and selected was all the patients (70) who were admitted to Yonsei University Hospital from October 1 - 15, 1975. The direct interview method was used and the data were categorized by the investigator, according to the nature of responses to each question and were subjected to the percentile and the chi- square tests. The findings can be summarized as follows 11. General characteristics of the study population ; The population was made up mainly of urban patients who were highly educated. The age was equally distributed. 2. Patients, perceptions and expectations related to illness and hospitalization ; 88.6% of the patients knew about the reason for hospitalization but 64. 5% could state symptoms only. 37.5% recognized the cause of illness. Approximately three fourth of the patients expressed on expectation for early recovery. 60.0% of the patient responses indicated, that they expected less than 10 days of hospitalization. Of the total responses regarding hospitalization, 45.7% were negative about the post -hospitalization expectation, 45.7% expected to return to work. As a result of these findings, we can see that there is a great educational need, a psychological need and environmental need for adaptation to the hospital and a socio- economic need for the post - hospitalization period. 3. Specific basic needs : The physical needs include the problem of getting sufficient sleep (50.0%), difficulty in food intake(47.1%), problems with hospital diet (47.0%), abnormal condition of the skin(44.3%), problems with bowel elimination(35.7%), assistance with bathing(35.7%), pain(30.0%), difficulty in walking(30.0%) , difficulty in seeing(30.0%) problems in urinary elimination(20.0%) , and difficulty in hearing(10.0%), 4. Nursing needs and epidemiological characteristics ; Age distribution was related to the rendition of the mouth but no significant differences were observed statistically with the patients responses to the other nursing history questions according to the epidemiological variables of age, sex, education and residence.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.141-153
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• 2016

The increase in frequency and scale of natural disasters is the typical negative examples of the global climate change and the change of the human living environment in cities. The damage caused by natural disasters in particular including human and physical damage is directly linked to the safety and properties of citizens. Besides, the damage may occur to SOC facilities directly or indirectly. The SOC facilities damaged by disasters cause infringement of citizens safety rights. Therefore, a plan to provide prompt and effective risk map information by linking a 3D disaster information display system, which handles the information of the damage that may occur to SOC facilities such as bridges, beams, and dams at the time of disasters, with an on-site assistance application is suggested in this study. The prompt provision of risk map information is defined as a dynamic expression technology in this study. Also, disaster information is processed and compressed with a module developed to be linked organically to a system that displays disaster information, a proliferation system that can use the information on site, and a DB system that constructs a relationship with the information. Based on the module, the effective disaster information compression plan will be prepared, and the prompt information transmission system will be secured in the future.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.180-196
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• 2016

To minimize the damage from disasters, various aspects of prevention, preparation, and response, etc. are being managed. Even though prevention and preparation are well conducted, irresistible calamities such as natural disasters may cause unexpected damage. Therefore, a system that can share the identical disaster information based on prompt disaster management and prediction must be developed and constructed for integrated disaster management. Especially, for a prompt disaster response, the same information needs to be shared between the related organization and the disaster prevention personnel such as on-site officials. Recent disaster management systems use high-capacity geographic information or other various factors for accurate disaster predictions. In case of using a recently constructed or researched 3D GIS, the system may not be used in some cases due to conflicts with hardware, etc. Thus, even though response information is secured using prediction simulation in advance, it is essentially difficult in some cases to share the common information when the system cannot be utilized or the extension of the corresponding data cannot be read. Therefore, this study aims to construct a system for dealing with disasters that shares the same prompt and accurate information in compliance with common data formats. The system is expected to reduce the existing disaster response time and minimize human and physical damage by assisting decision making through prompt responses.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.747-754
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• 2000

DNA damages in post-mortem bovine muscle samples caused by gamma irradiation at doses of 1 to 10 kGy were determined by Comet assay. When the cell extract was prepared in a physical method and followed by neutral lysis and neutral electrophoresis, the optimal comet images could be obtained. DNA damages were evaluated from the mean tail length, the distributions of comet images in 4 groups divided by tail length and the relative damage index (RDI) values calculated from the distribution pattern. The mean tail length and RDI value were increased by increasing the irradiation dose, and the RDI value was found to be useful as an index for discriminating of irradiation and measuring the irradiated dose. Blind tests using Korean domestic (Hanwoo) and imported beef samples showed a higher RDI value for the latter. However, the value was lower than those of irradiated samples indicating that the cause of DNA damages in the imported beef samples might be not irradiation but low-temperature treatments. It was concluded from the results of this study that the irradiated beef and its irradiated dose could be detected and predicted by Comet assay.

• Journal of Communications and Networks
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• v.14 no.4
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• pp.374-384
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• 2012

Utilizing artificial noise (AN) is a good means to guarantee security against eavesdropping in a multi-inputmulti-output system, where the AN is designed to lie in the null space of the legitimate receiver's channel direction information (CDI). However, imperfect CDI will lead to noise leakage at the legitimate receiver and cause significant loss in the achievable secrecy rate. In this paper, we consider a delayed feedback system, and investigate the impact of delayed CDI on security by using a transmit beamforming and AN scheme. By exploiting the Gauss-Markov fading spectrum to model the feedback delay, we derive a closed-form expression of the upper bound on the secrecy rate loss, where $N_t$ = 2. For a moderate number of antennas where $N_t$ > 2, two special cases, based on the first-order statistics of the noise leakage and large number theory, are explored to approximate the respective upper bounds. In addition, to maintain a constant signal-to-interferenceplus-noise ratio degradation, we analyze the corresponding delay constraint. Furthermore, based on the obtained closed-form expression of the lower bound on the achievable secrecy rate, we investigate an optimal power allocation strategy between the information signal and the AN. The analytical and numerical results obtained based on first-order statistics can be regarded as a good approximation of the capacity that can be achieved at the legitimate receiver with a certain number of antennas, $N_t$. In addition, for a given delay, we show that optimal power allocation is not sensitive to the number of antennas in a high signal-to-noise ratio regime. The simulation results further indicate that the achievable secrecy rate with optimal power allocation can be improved significantly as compared to that with fixed power allocation. In addition, as the delay increases, the ratio of power allocated to the AN should be decreased to reduce the secrecy rate degradation.

• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.435-444
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• 2016

In Korea, approximately 48% of all households live in apartments, which are a form of multi-unit dwellings, and this figure increases up to 58%, when row houses and multiplex houses are included. As such, majority of the population reside in multi-unit dwellings where they are exposed to the problem of floor impact noise that can cause disputes and conflicts. Accordingly, this study was conducted to manufacture a high-weight, high-stiffness foamed concrete in order to develop a technology to reduce the floor impact noise. For the purpose of deriving the optimum mixing ratio for the foamed concrete that best reduces the floor impact noise, the amounts of the foaming agent, lightweight aggregate and binder were varied accordingly. Also, the target characteristics of the concrete to be developed included density of over $0.7t/m^3$, compressive strength of over $2.0N/mm^2$ and thermal conductivity of under 0.19 W/mK. The results of the experiment showed that the fluidity was very excellent at over 190 mm, regardless of the type and input amount of foaming agent and lightweight aggregate. The density and compressive strength measurements showed that the target density and compressive strength were satisfied in the specimen with 50% foam mixing ratio for foamed concrete and in all of the mixtures for the lightweight aggregate foamed concrete. In addition, the thermal conductivity measurements showed that the target thermal conductivity was satisfied in all of the foamed concrete specimens, except for VS50, in the 25% replacement ratio case for Type A aggregate, and all of the mixtures for Type B aggregate.