• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.274-282
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• 2022

In order to secure pedestrians' right to walk, we have up-cycled second hand mobile phones to overcome limitations of the existing survey methods, analysis methods, and diagnosis to reduce pedestrian traffic accidents. Second hand mobile phones were up-cycled to produce mobile CCTVs and installed in areas where pedestrian deaths rate is high to secure image data sets for the period of more than 24 hours. It was analyzed by applying image visualization technology and clouding reporting technology, and more precise and accurate results were derived through modeling based on artificial intelligence learning and GIS-based diagnostic guidance. As a result, it was possible to analyze the risk factors and number of pedestrian safety, and even factors that were not known in the existing method could be derived. In addition, the traffic accident risk index was derived by converting data into one year to verify whether second hand mobile phone up-cycling mobile CCTV will be an objective tool for finding pedestrian risk factors. Up-cycling mobile CCTV of second hand mobile phones newly applied through research can be used as a new tool to find pedestrian risk factors, and it can be used as a service to protect the safety of the traffic vulnerable other than pedestrians.

• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.90-97
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• 2018

As the result(also after it's been carried out the damping force test with 800ea lateral dampers of 50ea trainset from entering heavy maintenance workshop to implement heavy maintenance inspection cycle, there were 86.25%(650ea) which were out of $350kg{\pm}15%$ of the standard value of damping force compared to the reference value. After the implementation of heavy maintenance inspection cycle, it's been examined damping force test with total samples 32ea(samples 8ea per a trainset) from actual running EMU 4ea trainset. As the result, percent defective was 84.4%(27ea), which was a very high level. System. The lateral damper's the failure cause of damping force defective was oil leakage caused by tearing crack of oil seal and foreign material in oil iron 473 ~ 1932 times higher than that of new oil, copper 36 ~ 98 times higher than that of new oil reduced oil amount cycling damping valve. It resulted from the change cause of damping force. In the static analysis on the shape of lateral damper oil seal's the existing and improved product, the stress of the improved product was smaller than that of the existing product. In the fatigue analysis, the existing product showed a low life in the upper area. However, in case of the improved product, it could be confirmed that the destruction did not occur up to the specified 1.0e + 006 cycles and the lifetime was further improved in most areas.

• Journal of Korean Academy of Nursing
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• v.35 no.3
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• pp.555-564
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• 2005

Purpose: This study was done to uncover the nature of hope experienced by clients with chronic schizophrenia. Method: A phenomenological approach developed by Van Manen was adopted. Data was collected from intensive interviews on 7 clients with chronic schizophrenia and the expatients' biographies and arts. A phenomenological reflection was done in terms of the four life world existentials. Result: Corporeality: Perceiving the body feeling better, proudness of self, accepting their own ill body and transcending the limitation of the body, expressing self, and staying within the boundary of a healthy body were disclosed as the body's experience of hope. Spatiality :A place with safety, freedom, peace, and sharing was the space of hope. Temporality :The essential experience of time with hope was the continuity of moving forward amid cycling and moments being filled up with something. Relationality : Connecting with someone, having someone who is dependable, understandable and exchanging interest and love were identified as the relationships of hope with others. Conclusion: The results of this study show that chronic schizophrenic patients always strive hard to keep hope and they really need someone who can support them.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.12
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• pp.101-108
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• 2005

The GPS(Global Positioning System) receiver for satellite launch vehicles which will be mounted on a launch vehicle can be applied to the flight safety system with its accurately calculated position and velocity data during vehicle's flight. This paper analyzes the performance of the GPS receiver such as SNR(Signal to Noise Ratio), fix mode, position and velocity error, number of visible and tracking satellites, and PDOP(Position Dilution of Precision) under temperature variation which is changed from -34$^{\circ}C$ to +71$^{\circ}C$.

• Structural Monitoring and Maintenance
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• v.1 no.3
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• pp.273-292
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• 2014

The effectiveness of a retrofitting method for concrete columns with particular weaknesses is experimentally evaluated and presented in this paper. Structural deficiencies namely the inadequacy of transverse reinforcement and short length of lap splices are very common in columns found in structures built prior to the 1960s and 1970s. Recent earthquakes worldwide have caused severe damages and collapses of these structures. Nevertheless, the importance of improving the load transfer capacity between the deficiently lap-spliced bars is usually underestimated during the strengthening procedures applied in old buildings, though critical for the safety of the residents' lives. Thus, the seismic performance of the enhanced columns is frequently overestimated. The retrofitting approach presented herein involves reinforced concrete jacketing of the column sub-assemblages and welding of the lap-spliced bars to prevent the splice failure and conform to the provisions of modern design Codes. The cyclic lateral loading response of poorly confined original column specimens with insufficient lap splices and the seismic behavior of the retrofitted columns are compared. Test results clearly demonstrate that the retrofitting procedure followed is an effective way of significantly improving the seismic performance of substandard columns found in old buildings.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.216-225
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• 1998

본 연구는 자전거 관련 연구의 세계적 동향을 파악하기 위한 것으로써 70년대 이후자전거 연구와 관련된 세계 각 국의 학위논문, 단행본, 학회발표논문, 기사 등을 분석의 대상으로 하였다. 이를 통하여 세계 각 국의 자전거 연구의 흐름을 살펴보고, 앞으로 자전거 연구의 추세를 전망하며, 우리나라의 자전거 관련연구 및 정책에의 방향을 제시하는데 그 목적이 있다. 70년대 이후 최근까지 자전거 관련연구를 살펴보면, 주제의 양적인 면에서 자전거 관련시설(Facilities, 정책(Policy), 이용의 형태(Type of cycling)등이 전체의 52%를 차지하고 있으며 국가별로 북미의 미국, 캐나다, 유럽의 영국, 독일, 네덜란드 등 주로 선진국에서 활발한 연구가 진행되고 있는 것으로 나타났다. 시기별 자전거 관련연구의 변화추이를 보면 70년대 이후 80년대 전반가지 자전거 관련연구의 초창기에는 시설,(Facilities), 정책(Policy), 이용형태 등이 연구의 많은 비중을 차지하였지만 80년대 이후 점차 교육(Education), 타 교통수단과의 관계(Relationship), 안전(Safety), 등에 관한 주제의 연구 비중이 높아지고 있는 것으로 나타났다. 국가별·시기별 자전거 연구에 있어서 전체적으로 정책 및 시설에 있어 국가간에 비슷한 비율로 연구되고 있는 것으로 나타났으나 유렵의 경우 설계(DESIGN)의 비중이 높으며 북미지역에서는 교육에 대한 비중이 높은 것으로 나타났다. 한편, 우리나라는 총 61편중 90년대 이후의 연구가 전체의 74%를 차지하고 있어 비교적 최근에 관심을 가진 것으로 나타났으며 주제별로 보면 효과(Effectiveness), 정책, 계획 등에 관련된 주제가 64%를 차지하고 있다. 특히 시설, 교육, 안전에 관련된 연구는 매우 부족하여 자전거 관련연구 및 정책의 초창기에 있는 우리나라에 시사하는 바가 크다고 볼 수 있다. 따라서 앞으로의 연구방향에 있어 도로, 시설 등의 기초분야와 더불어 안전과 교육에의 관심이 필요하다고 하겠다.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.6 no.2
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• pp.54-60
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• 2010

Piping failures due to thermal fatigue have been widely reported in normally stagnant non-isolable reactor coolant branch lines. Since the thermal fatigue due to thermal stratification was not considered in the piping fatigue design in old NPPs, it is important to evaluate the effect of thermal stratification on the integrity of branch lines. In this study, geometrical screening criteria for Up-horizontal branch lines in MRP-132 were applied to SI(Safety Injection) lines of KSNP 2-loop and WH 3-loop. Some computational fluid dynamic(CFD) analyses on the Reactor Coolant System(RCS) branch lines were also performed to develop the regulatory guidelines for screening criteria. As a result of applying MRP-132 screening criteria, KSNP 2-loop and WH 3-loop SI lines are determined to need further detailed evaluation. Results of CFD analyses show that both valve isolation and amount of leakage through valve can be used as technical bases for the screening criteria on the thermal fatigue analysis.

• Journal of Power Electronics
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• v.17 no.3
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• pp.811-820
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• 2017

The reliability issue of IGBT is a concern for researchers given the critical role the device plays in the safety of operations of the converter system. The reliability of power devices can be estimated from the intermittent life test, which aims to simulate typical applications in power electronics in an accelerated manner to obtain lifetime data. However, the test is time-consuming, as testing conditions are not well considered and only rough provisions have been made in the current standards. Acceleration of the test by changing critical test conditions is controversial due to the activation of unexpected failure mechanisms. Therefore, full investigations were conducted on critical test conditions of intermittent life test. A design optimization process for IGBT intermittent life testing program was developed to save on test times without imposing additional failure mechanisms. The applicability of the process has been supported by a number of tests and failure analysis of the test results. The process proposed in this paper can guide the test process for other power semiconductors.

• Korean Journal of Materials Research
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• v.32 no.2
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• pp.107-113
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• 2022

Fibrous supercapacitors (FSs), owing to their high power density, good safety characteristic, and high flexibility, have recently been in the spotlight as energy storage devices for wearable electronics. However, despite these advantages, FCs face many challenges related to their active material of carbon fiber (CF). CF has low surface area and poor wettability between electrode and electrolyte, which result in low capacitance and poor long-term stability at high current densities. To overcome these limits, fibrous supercapacitors made using surface-activated CF (FS-SACF) are here suggested; these materials have improved specific surface area and better wettability, obtained by introducing porous structure and oxygen-containing functional groups on the CF surface, respectively, through surface engineering. The FS-SACF shows an improved ion diffusion coefficient and better electrochemical performance, including high specific capacity of 223.6 mF cm^-2 at current density of 10 ㎂ cm^-2, high-rate performance of 171.2 mF cm^-2 at current density of 50.0 ㎂ cm^-2, and remarkable, ultrafast cycling stability (96.2 % after 1,000 cycles at current density of 250.0 ㎂ cm^-2). The excellent electrochemical performance is definitely due to the effects of surface functionalization on CF, leading to improved specific surface area and superior ion diffusion capability.

• Journal of Applied Biological Chemistry
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• v.54 no.2
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• pp.108-113
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• 2011

The tyrosinase inhibitory activity of extracts from Phellodendron amurense was examined. Tyrosinase inhibitory activity of 60% ethanol extracts was determined as 25% and the inhibitory activity of 60% ethanol extracts against melanin biosynthesis in melanoma cell (B16F10) was 31.2%. The purified inhibitory compounds against tyrosinase by Sephadex LH-20, MCI-gel CHP-20 column chromatography from P. amurense was confirmed as obacunone by $^1H$-NMR, $^{13}C$-NMR and Fast atom bombardment (FAB)-Mass spectrum. The tyrosinase inhibitory activities of purified obacunone was respectively as 35.1%. The safety of essence with tyrosinase inhibitory compounds from P. amurense was also assayed by various safety profiles. First, pH and viscosity change of essence for 60 days were not detected. The essence also showed the stability against temperature and light for 60 days. All these findings suggest that extracts from P. amurense has a great potential as a cosmeceutical ingredient, which has a potent whitening effect.