• Structural Engineering and Mechanics
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• v.87 no.3
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• pp.273-282
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• 2023

Concrete construction, one of the oldest building practices, is commonly used in all parts of the world. Concrete is the primary building material for both residential and commercial constructions. The challenge of protecting the buildings, hence nation, against the attack of terrorism has raised the importance to explore the understanding of building materials against the explosion. In this research, a security check-post (reinforced concrete frame filled with plain cement concrete) has been chosen to study the behavior of structural elements under blast loading. Eight nitroglycerines-based dynamite blasts with varying amounts of explosive charge, up to 17 kg weight has been carried out at various scale distances. Pressure and acceleration time history records are measured using blast measuring instruments. Security check post after being exposed by explosive loading are photographed to view cracking/failure patterns on the structural elements. It is noted that with the increase of quantity of explosive, the dimensions of spalling and crack patterns increase on the front panels. Simple empirical analyses are conducted using ConWep and other design manuals such as UFC 3-340-02 (2008) and AASTP-1 (2010) for the purpose of comparison of blast parameters with the experimental records. The results of experimental workings are also compared with earlier researchers to check the compatibility of developed equations. It is believed that the current study presents the simple and preliminary procedure for calculating the air blast and ground shock parameters on the structures exposed to blast explosion.

• Journal of Hydrogen and New Energy
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• v.34 no.5
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• pp.514-525
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• 2023

This study conducted numerical simulations with the purpose of analyzing the impact of variations in outlet pressure conditions under extreme temperature conditions on the fluid dynamics and performance of a check valve utilized in hydrogen refueling systems. Under the extreme temperature conditions, changes in outlet pressure conditions of the check valve were investigated to analyze velocity distributions, pressure distributions, and temperature distributions in the operational and connection regions. The analysis results indicated that changes in outlet pressure had a significant influence on the internal temperature variation of the check valve. Furthermore, due to density variations in the connection region caused by the cooling effect of excessively cooled hydrogen, a bias in the primary flow direction towards the lower part of the valve outlet was observed in the outlet area. Through a comparison of the results of the valve's inherent flow performance, represented by the flow coefficient, it was observed that when the pressure difference between the inlet and outlet was below 0.37 MPa, sufficient flow was not ensured.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.8
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• pp.843-849
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• 2009

The reliable operation of a swing check valve in the main feed water system of a power plant is most essential for successful shout-down process. A failure to close the valve at proper time often leads to the instability of the main feed water system, or even to an emergency stop of the power plant. In reality it is a very difficult task to monitor the behavior of a swing check valve. Furthermore it is impossible to see the motion of the valve. In this work two measurements were carried out simultaneously to determine the precise valve closure time. The dynamic pressure measurements were made at the inlet and outlet regions of the swing check valve. The transient vibration of the valve housing in the direction of water flow was also measured, which enabled the measurement of the transient vibration of the valve housing near valve closure. By comparing the results produced from these measurements the precise valve closure time could be determined. By carrying out order tracking technique using the dynamic pressure signals and pump rpm signal, the complicated dynamic problems inside the main feed water system can be more easily dealt with. This measurement scheme might be implemented in a power plant on a real-time basis without much difficulty. If this could be implemented, valuable information essential for shut-down operations can readily be passed on to the main control room. The feasibility of this implementation was demonstrated by this experimental work.

• Journal of Digital Convergence
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• v.10 no.2
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• pp.269-278
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• 2012

In this research, the factor having an effect on the cancer check inspection through the cancer check service and process, of desiring against the cancer check examinee living in the illustration and rural area environment, and analysis about the result tries to be sought for. This research performed the frequency analysis, cross analysis, t-test, ANOVA, and multiple regression analysis and came to the conclusion. The examination reservation procedure, medical team professionalism, examination contents of notice, result of medical examination explanation, examination notification date, and examination duration of subscription was analyzed as the significance factor as the factor reached to the urban district inspection. And the examination contents of notice, total examination time, result of medical examination explanation, medical team professionalism, examination duration of subscription, and process of the medical examination explanation as to rural area, was analyzed as the significance factor. The cancer check was inspected according to the illustration and farming village and there was no big difference in the significance factor having an effect on the inspection. However, the Profiling about the examination procedure and service has to be continuously performed. And the differentiation strategy and policy considering the illustration and fairness between rural areas are required.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.11 no.1
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• pp.25-47
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• 2007

Background and Purpose: There was seldom study about method that diagnose 8 Constitution beside method of pulse diagnosis in 8 Constitution Medicine. Objectives: This study is to make out check list for 8 Constitution Medicine Diagnosis Expert System Development used CBR(Case based Reasoning). Methods: Review of literatures about special quality element of 8 Constitution and supplement learning advice of 8 Constitution Medicine Experts constructed knowledge base. And then, knowledge base divided through AHP(Analytic Hierarchy Process), and made out check list with this. Results: Knowledge base based on special quality element of 8 Constitution was divided by 5 greate classification and 25 bisection kind, and check list consisted of 251 item was made out through this. Conclusion: Based on this research, cases necessary to make 8 Constitution Medicine Diagnosis Expert System can be gathered through check list, and further study for 8 Constitution Medicine Diagnosis Expert System Development used CBR(Case based Reasoning) is needed to supplement this research.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.365-372
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• 2012

Native of soybean aphid (Aphis glycines Matsumura) is an Asia and aphid is one of the dangerous pests in soybean [Glycine max (L.) Merr.]. High density aphid populations can reduce crop production by causing severe damage. The objective of this study was evaluation of resistance to the soybean aphid in soybean cultivars and germplasms. A total of fifty five soybean cultivars or germplasms, including two susceptible and two resistant check varieties, were infested to evaluate their resistance in the field cage and greenhouse test by aphid colonies which derived from wild collected one soybean aphid biotype in Korea. The average number of reproduced soybean aphid was evaluated with 62.7 aphids in the resistant check variety PI 567598B and also estimated with 1,807 aphids for susceptible check variety Williams 82. In soybean varieties and germplasms, the average reproduced soybean aphid populations ranged from the lowest 497 aphids for Junjeori to the highest 3,862 aphids for Mansu. About seventy six percent of soybean cultivars and germplasms were shown high density soybean aphid populations when compared with another susceptible check variety PI 567543C in the field cage test. From the greenhouse test to evaluate aphid index, 87.3% of soybean cultivars or germplasms presented aphid index with 9.0. No soybean cultivars and germplasms were observed with soybean resistant phenotype when regarded a aphid resistant level as less than 10% aphid reproductions compared with susceptible check Williams 82. Although no Korean soybean cultivars were identified with resistant trait to the soybean aphid, we found one great resistant genetic resource PI 567598B in this study. This result will be helpful to further study for providing useful genetic information for soybean researchers.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.828-841
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• 2016

Relatively little information is available regarding the correlation between wood and veneer quality, especially for Samama wood, an endemic wood species in eastern Indonesia. This study addresses the quality of 8 years old Samama wood and its effect on the veneer quality. Samama wood quality was determined by evaluating its specific gravity, moisture content, fiber dimensions, and microfibril angle from pith toward bark. Meanwhile, veneer quality was assessed by examining veneer thickness and lathe check characteristics. Geometry factor model was constructed to elaborate the quantities of lathe check from pith toward bark. Results show that fair variations of veneer thickness, ranging from 1.5 mm to 3.0 mm, could be obtained from Samama wood. The quantity, depth, and length of lathe check were noticeably decreasing toward bark. Further, in the same manufacturing process, geometry factor was determined as the dominant factor over other wood properties in affecting the frequency of lathe checks from pith towards bark. These facts should be put into consideration in producing veneer from Samama wood. Moreover, these results enlighten the potential of Samama wood as plywood and other excellent veneer-based products.

• Korean Journal of Construction Engineering and Management
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• v.5 no.1 s.17
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• pp.124-132
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• 2004

A human resource management of the general contractors is to mostly deal with daily input by each subcontractor in construction fields. However, this way has some limitations; the identification of proper human-input and productivity, preventive activities or efforts for minimizing schedule delay. The reason why these limitations are that few systematic efforts through a coordinated field administration with the construction schedule planning and human resources. Therefore, on the basis of the construction schedule planning, human resource management of subcontractors is necessary to make for an improvement in construction schedule control. Daily Scheduling Check System(DSCS), as the linked human resources on an existed CPM scheduling software, was developed and this paper then verified validity and effectiveness of using the DSCS for the framework of some actual apartment construction projects

• Resources Recycling
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• v.10 no.1
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• pp.56-65
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• 2001

Chemical decontamination techniques have been employed to reuse the high cost check valves contaminated with radioactivity and to reduce the radiation exposure during the inspection and maintenance work of safety injection system containing check valves. After chemical decontamination, an ultrasonic treatment was conducted to remove the fine solid particles retained in the crevices of check valves. The decontamination process conditions and the amount of chemical reagents were determined from the results of a pre-test, using the (list arm holder. The decontamination factors (DF), estimated from the activity in the solution, ranged from 14.5 to 18.5 corresponding to the activity removal of 93-95ft. The corrosion test data indicated that the general corrosion rate during a chemical decontamination-ultrasonic treatment process are low for type 304 S tainless steel, Inconel -600 and Stellite-6 materials $ (2.1\times10^{-2}$ $6.0\times10^{-2}$ and$ 1.7\times10^{-2}$ mil, respectively).

• Journal of agricultural medicine and community health
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• v.9 no.1
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• pp.39-45
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• 1984

This research was done to gain the health information in one of the target areas(rural area) of the Korea University Community Health Project, and to improve and standardize the methodology of the health interview survey. There were two types of questions;one was the simple open-ended question and the other was check list in the interview survey for a total of 1,406 inhabitants. And so the result obtained from the above survey was analysed. The results as follows; 1) The morbidity rate in general was 11.2% by simple open-ended question and 32.5% by check list during recent 20 days in interview method. 2) Women had higher morbidity rate in both kinds of method. 3) The most prevalent diseases in the interview method using check list were the ones of the musculo-skeletal system and connective tissue (22.5%), and diseases of the respiratory system (19.8%) and digestive system (13.7%) were in order of frequency. 4) By the position in the family, housewives had highest morbidity rate in the interview method unrespectedly, and the reason seemed that the respondents were houseweives themselves and the morbidity rate was the one by spell not by person. But morbidity rate by the socio-economic status had no significant difference in both methods. 5) The agreement rate on simple open-ended question and check list was 72.5%, but if limiting respondents themselves only, the rate was falled to 54%. 6) The morbidities were diverse in the review of the results of previous morbidity surveies, but the morbidity rate was higher and less variable in case of using check list and getting the replies individually than using simple open-ended question and proxy respondents.