• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1089-1095
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• 2005

This paper presents a new low-cost Built-In Self-Test (BIST) circuit for 50Hz low noise amplifier (LNA). The BIST circuit is designed for system-on-chip (SoC) transceiver environment. The proposed BIST circuit measures the LNA specifications such as input impedance, voltage gaih, noise figure, and input return loss all in a single SoC environment.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.3
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• pp.223-228
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• 2010

The mount which is used in military airplane should be operated in various situations such as vibration, shock and temperature. The recent mounts cost a lot and take much time to replace when they broke down. That's why new mount was produced in domestic by reverse engineering and the product has been proved its performance through environment test regarding vibration and shock. According to simulation of dynamic characteristics on vibration and shock, the result turns out to be similar to the result of the environmental test with an error of within 10 percent. As a result this research, a draft of the military aviation mount designing program is arranged.

• Journal of the Korean Wood Science and Technology
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• v.50 no.3
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• pp.167-178
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• 2022

To investigate the influence of manufacturing environment on bonding performance of mixed cross laminated wood (CLT) using polyurethane (PUR) adhesive, a boiling water soak delamination test according to the temperature and relative humidity was conducted. The 5-ply mixed CLT consisted of Japanese Larch for external and middle layer and yellow poplar for internal layer. The PUR adhesives with different opening times of 10 and 30 minutes were used. The mixed CLT was manufactured according to pressing times of PUR and manufacturing environments of summer and winter. In case of summer environment, the delamination rate of the mixed CLT with pressing time of 4 hours using a PUR adhesive with open time of 10 minutes met the requirements of KS F 2081. In case of winter environment, the delamination rate of the mixed CLT didn't meet the requirements of KS standard. However, it was possible to confirm the effect of improving the adhesive performance by adjusting the pressing time according to the open time of the adhesive under the manufacturing conditions. The delamination rate of CLT with open time 30 minutes PUR, manufactured by indirect moisture supply methods was 11.2% better than direct moisture supply methods. As a result of delamination test in the same condition of relative humidity and adhesive, it was found that the temperature of manufacturing environment influences the adhesive performance.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.306-310
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• 2009

Packed-bed reactor for removing ammonia was tested at different loading rates. Nitrifiers for ammonia removing was encapsulated in gel media which consisted of polyethlene glycol, alginate and activated carbon. The removal efficiency was nearly 100% when ammonia loading was $12g/m^3/hr$, and the maximum elimination capacity (EC) achieved on this study was $18g/m^3/hr$. The initial microbial portion of nitrifiers in the media was about 82% and it was increased to more than 90% at the end of the operation. Short-term shock loading test was carried out to survey the stability of the media. The inlet loading rates were varied from 2 to $20g/m^3/hr$. The packed-bed reactor overcame the shock loading i.e. removal efficiency recovered rapidly from about 80% to almost 100% within 6 hrs. The results of Live/Dead cell test showed that nitrifiers maintained there activity in the encapsulated media during the test and also against ammonia shock load.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.1
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• pp.93-102
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• 2006

In order to use a recycled aggregate concrete for precast concrete box structures, the structural behaviors should be analytically and experimentally evaluated. In this study, full-scale precast concrete box structures are manufactured using the recycled aggregate (30% replacement) and natural aggregate. Then, the flexural failure test and shear failure test as well as water leakage lest for the structures arc carried out. First of all, test results of compressive strength show that recycled aggregate concrete is only 4% lower than normal concrete. In the flexural and shear failure test, the structural performances of precast box using the recycled aggregate concrete are 95% of the capacities of normal precast concrete box or more. Especially, the water leakage test shows that leakage pressure of recycled concrete box is more than the critical value, 60kPa, as well as 9% higher than normal precast concrete box. These test results are analyzed and compared with results of finite clement analysis. The comparison shows that test results are more excellent than analytical results. Also, the comparison confirms the applicability of recycled aggregate concrete for the use as practical precast concrete box structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.79-82
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• 2008

It has been reported that destruction test by core collection is the most reliable of the structural concrete strength in present building construction field. But it causes low efficiency by damage and cutting in structure due to the core collection. It also has some problems in repairing. Additionally in case of strength test with management specimen, different environment compared to the structure environment cause problems about estimation precise structure strength. Therefore, it is required to develop structure direct strength test that has test values and credibility above the ones obtained by core specimen collection strength test and seasonal specimen test to suggest a reasonable and practical management method of structural concrete.

• Journal of Software Engineering Society
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• v.28 no.1
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• pp.7-12
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• 2019

Recently, as the weight of software in the weapon system increases, the quality of the software becomes a very important factor. In order to improve the quality of the weapon system software, DAPA(Defense Acquisition Program Administration) has institutionalized software reliability in Weapon System Software Development and Management Manual. The manual presents specific methods and procedures to improve the weapon system software quality. In order to meet the required reliability test standards specified in the manual, it is necessary to continuously detect and correct defects throughout the entire development period. However, it is difficult to build proper reliability test environment due to the cost of software reliability tools, setting up secured and separated network environment, and etc. Therefore, in this study, we propose an efficient environment construction method for software reliability test of defense industry field in restricted development environment and limited resources.

• Journal of People, Plants, and Environment
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• v.22 no.6
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• pp.563-573
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• 2019

The North Korean government conducted its first nuclear test in 2006 and more recently the sixth nuclear test on September 3, 2017. In order to identify how North Korea's nuclear tests have affected the environment, a scientific approach is required. Although North Korea's nuclear tests and their environmental destruction are not a severe threat to the environment of the Korean Peninsula at this time, identifying environmental damage and taking countermeasures in advance are essential to minimize their potential threats to the environments. The purpose of this study is to study the environmental impact of North Korea's nuclear tests using Google Earth image analysis. As a method of the study, we compare Google Earth images taken before and after each nuclear test was conducted in North Korea. To overcome limitations of the suggested comparison method, we cross-checked our results with those of previous scientific research. After the 1st-3rd nuclear tests, green spaces were found to be considerably reduced. In particular, when comparing the Google Earth images before and after the second nuclear test, some ground subsidences were observed. Such subsidences can cause tunnels on the mountainsides and cracks in rocks around the mountains, leading to the release of radioactive materials and contaminating groundwater. Besides, after the 4th-6th nuclear tests, decay and deforestation were observed not in the nuclear test sites, but in their surrounding areas. Especially after the 5th and 6th nuclear tests, the topography and the forests of the surrounding areas were severely damaged. In relation to North Korea's nuclear tests and their impact on the natural environment, we need to prepare various policy measures to reduce North Korea's environmental pollution and natural environment destruction. Those policy measures include the establishment of various cooperative governance between the Korean government, the private sector, the academia, NGOs, and international organizations.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.2
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• pp.83-95
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• 2023

The purpose of this study was to identify the effect of skin care salons' decision factors on customer satisfaction and revisit intention during the COVID-19 pandemic. The subjects of this study were 220 women in their 20s to 50s who reside in Seoul and the Gyeonggi-do area and are users of skin care salons. The data was statistically analyzed using SPSS V.25.0 and detailed research results are as follows. For the analysis of this study, frequency analysis, factor analysis, reliability verification, independent sample T-Test, one-way analysis of variance, post hoc test, Duncan test, and regression analysis were conducted. First, as a result of examining whether skin care salon decision factors during the pandemic have a positive (+) effect on customer satisfaction, hygienic environment satisfaction and service environment satisfaction, which are sub-factors of customer satisfaction, had a significant effect on professionalism, kind service, and distance, which are sub-factors of decision factors, and are independent variables. Second, as a result of examining whether skin care salon decision factors during the pandemic have a positive (+) effect on revisit intention, decision factors, which are independent variables, including professionalism, kind service, price, and distance showed significant effects on human revisit intention, As for physical revisiting intention, only kind service, distance, and professionalism showed significant effects, while price did not have a significant effect. Third, as a result of examining whether customer satisfaction during the pandemic has a positive (+) effect on revisiting intention, the service environment satisfaction and hygienic environment satisfaction, which were sub-factors of independent variables, showed significant results for human and physical revisit intentions. In this study, service environment and hygienic environment satisfaction were important variables for skin care salon decision factors. Professionalism and kind service were important for human revisit intention. Therefore, overall service environment, hygiene, and safety should be prioritized to increase revisit intention and efforts must be made to retain and improve customer satisfaction

• KIPS Transactions on Software and Data Engineering
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• v.3 no.7
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• pp.243-254
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• 2014

When building a testing environment with a testing platform, the configuration of test executor and its interface should be built to be appropriate for the system under test (SUT). That is, it is necessary to build the test executor and interface environment that can properly handle the input and output signals of SUT. If the testing platform is not extendable, it should be modified significantly whenever new SUTs and models are tested. It is a serious drawback that the test executor and interface configuration need to be modified depending on testing targets. To overcome the drawback, this paper proposes TEM(test Execution Machine), which allows for test executor to reconfigure its environment suitable to new SUTs by modifying the configuration file. The proposed TEM is verified through testing two real systems.