• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.141-148
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• 2013

This paper proposes an EMS algorithm designed to determine the optimal locations for Emergency Medical Service centers that both satisfy the maximum ambulance response time T in case of emergency and cover the largest possible number of residents given a limited number of emergency medical services p in a city divided into different zones. This methodology generally applies integer programming whereby cases are categorized into 1 if the distance between two zones is within the response time and 0 if not and subsequently employs linear programming to obtain the optimal solution. In this paper, where p=1, the algorithm determines a node with maximum coverage. In cases where $p{\geq}2$, the algorithm selects top 5 nodes with maximum coverage. Based on inclusion-exclusion method, this selection entails repeatedly selecting a node with the maximum coverage when nodes with lower numbers are deleted. Among these 5 selected nodes, the algorithm selects a single node set with the greatest coverage and thereby as the optimal EMS location. The proposed algorithm has proven to accurately and expeditiously obtain the optimal solutions for 12-node network, 21-node network, and Swain's 55-node network.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.427-431
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• 2012

This study was conducted to monitor and evaluate microbial contamination during manufacturing process in 6 red pepper powder factories. Red pepper powder samples were taken from manufacturing facilitates, working area and workers' hands to determine sanitary indicator bacteria (SIB) such as aerobic bacteria and coliform group as well as pathogenic indicator bacteria (PIB) such as Staphylococcus aureus, E.coli, Salmonella spp., Listeria monocytogenes, and Bacillus cereus. The results indicated that SIB in primary materials was detected as low as 3 log units and E.coil and Staphylococcus aureus of PIB were detected. After grinding process, aerobic bacteria, fungi, and coliform group increased 52% and 108%, respectively. In final products, PIB was not detected except for one found Staphylococcus aureus by which workers' hands were contaminated. Moreover, UV detectors in all the manufacturers were not able to reduce bacteria. Thus, this data suggest that a stringent safety management be needed to prevent cross contamination, and also reconsider effectiveness of facility.

• Journal of the Korean GEO-environmental Society
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• v.12 no.6
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• pp.25-34
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• 2011

Dredged and reclaimed ground in progress at the West Coast has a high content of coarse particles. There will be different behaviors depending on the location of outlet and engineering properties of soil when its ground is dredged by a pump. Therefore, the experiments were conducted that were manufactured about the chamber equipment of length 2,650mm, width 770mm, height 735mm, experimented step filling method and water content about 300%, 500% and 700% respectively with SM and ML samples in order to realize segregating sediment characteristics of dredged ground with changing much fine. With results of analysis, ML sample by higher initial water content was reached to the period of complete sedimentation and coefficient of sedimentation consolidation increased with increases of diffusion distance. SM samples showed behavior of coarse soil with diffusion distance 120cm, diffusion distance of more than 120cm showed a similar tendency with ML sample under the influence of fines. In ML sample, it could be also found that lower depth and the more increasing diffusion distance increase in percentage of sieve #200 but water content decreases. In SM sample, it could be also found that coarse soil was piled at near the diffusion distance zone but fine soil was piled at the far diffusion distance zone and prominent difference showed between percentage of sieve #200 and water content(%) by boundary point 120cm~160cm of both samples. Also, shear strength was expressed ML-maximum 2.97kPa, SM-maximum 10.2kPa with diffusion distance.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.15-22
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• 2020

PET(Positron Emission Tomography) devices are used as PET/CT or PET/MRI devices fused with the devices of CT or MRI for obtaining anatomical information. Therefore, the devices are constructed in circular ring-type structure whose length of gantry(the main part of filming) becomes wider and the interior depth becomes longer in comparison to other common medical equipments. scintillator, one of the components in PET devices, is inside the gantry, and as it is consisted of crystal which is sensitive to the change of temperature and humidity, large temperature change can cause the scintillator to be damaged. Though scintillator located inside the gantry maintains temperature and humidity with a thermo-hygrostat, changes in temperature and humidity are expected due to structural reasons. The output value was measured by dividing the inside of the gantry of the PET/CT device into six zones, each of which an Adafruit BME 280 temperature and humidity sensor was placed at. A thermo-hygrostat keeps the temperature and humidity constant in the PET/CT room. As the measured value of temperature and humidity of the sensor was obtained, the measured value of temperature and humidity appeared in the thermohygrostat was taken at the same time. Comparing the average measured values of temperature and humidity measured at each six zones with the average values of the thermo-hygrostat results in a difference of 2.71℃ in temperature and 21.5% in humidity. The measured temperature and humidity of PET Gantry is out of domestic quality control range. According to the results of the study, if there is continuous change in temperature and humidity in the future, the aging of the scintillator mounted in the PET Gantry is expected to be aging, so it is necessary to find a way to properly maintain the temperature and humidity inside the Gantry structure.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.180-193
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• 2014

In plants, a shoot apex has a small region known as the shoot apical meristem (SAM) having a group of dividing (initiating) cells. The SAM gives rise to all the groundabove structures of plants throughout their lifetime, and thus it plays important role in growth and development of plants. This review describes theories to explain the SAM organization and function developed over the last 250 years. Since in 1759 German botanist C. F. Wolff has described firstly the SAM, in 1858 Swiss botanist C. N${\ddot{a}}$geli proposed the apical cell theory from the observation of a large single apical cell in the SAM of seedless vascular plants: however, this view was recognized to be unsuitable to seed plants. In 1868, German botanist J. Hanstein suggested the histogen theory: this concept subdividing the SAM into dermatogen, periblem, and plerome was unable to generally apply to seed plants. In 1924, German botanist A. Schmidt proposed the tunica-corpus theory from the examination of angiosperm SAM in which two parts show different planes of cell division: this theory was proved to be not suitable to gymnosperm SAM, not have stable surface tunica layer. In 1938, American botanist A. Foster described zones in gymnosperm SAM based on the cytohistologic differentiation and thus called it a cytohistological zonation theory. With works by E. Gifford, in 1954, this zonation pattern was demonstrated to be also applicable to angiosperm SAM. As another theory, in 1952 French botanist R. Buvat proposed the m${\acute{e}}$rist${\grave{e}}$me d'attente (waiting meristem) theory: however, this concept was confuted because of its negation of function during vegetative growth phase to central initial cells. Rescent studies with Arabidopsis thaliana have found that formation and maintenance of the SAM are under the control of selected genes: SHOOTMERISTEMLESS (STM) gene forms the SAM, and WUSCHEL (WUS) and CLAVATA (CLV) genes function in maintaining the SAM; signaling between WUS and CLV genes act through a negative feedback loop.

• Korean Journal of Heritage: History & Science
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• v.50 no.4
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• pp.168-197
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• 2017

This paper considers two aspects of the wooden chamber tombs with stone mound that were constructed in Wolseong North Burial Ground, in Gyeongju: tomb form and the group tomb complex. The basic unit of a wooden chamber tomb with stone mound consisted of a single round mound, covered with an additional earthen layer and surrounded by a circle of protective stones, within which a single wooden chamber was located. The form of a wooden chamber tomb with stone mound could therefore 1) be round, consisting of a single tomb unit, 2) consist of two or more attached tomb units, 3) or consist of multiple attached chambers in a single mound. The single tomb contained the burial of a single individual, and the attached tomb contained two or more individuals who were blood relations or connected by marriage. Multiple attached chambers tombs usually consisted of wooden chamber burials of the lowest rank, and have only been identified in the royal burial area of Wolseong North Burial Ground. At the Jjoksaem Area of Wolseong North Burial Ground, which is currently, under investigation, tombs have been found in small clusters along the slightly raised ground. This is likely the result of small groups of kin relations, upon selecting points along the slightly raised ground as their burial area, having constructed midsized and large single tombs and attached tombs along the axis of the slightly raised ground, which were then surrounded by smaller 'satellite' tombs. It is through this process that the tomb complex of the different groups came to be formed. The tombs of the royal burial area of Wolseong North Burial Ground, including the Daereungwon Tomb Complex, also formed group tomb complexes. Forming the centers of the group tomb complexes of the royal tomb area were huge individual round tombs where the Maripgan rulers were laid to rest or a gourd-shaped dual mound tomb, which was the final resting place of the king and his queen consort. These central tombs were surrounded by large and smaller tombs. Of the individuals that were buried in the group tomb complexes, there would have been individuals that were of equal status or social position, such as husbands and wives or blood relations, but it is unlikely that all of the buried individuals were related by blood, given the significant difference in the sizes of the tombs. It is likely that the individuals buried in the lower ranked tombs included in the group tomb complexes were 'dependents' of the deceased of the central tomb and his or her direct family who maintained a subservient relationship. Such tomb forms and group tomb complexes that can be observed amongst the wooden chamber tombs with stone mounds of Wolseong North Burial Ground provide insights into the nature of the social groups of the Silla center during the Maripgan Period. It is hoped that future studies undertaking a more detailed analysis of the data may make further contributions to unveiling the various aspects of Silla society.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.827-830
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• 2008

The Center Based Navigation System(CBNS) used real time road data searches an optimal path. The other hand, the Terminal Based Navigation System(TBNS) used embedded road data searches a path that has less qualitative than the CBNS. But the TBNS has been favored, because it has no additional fees. Generally, TBNS has not used real time road data but it is recently able to use it with technique such as TPEG. However, it causes to increase a cost of exploring by using real time road data for improvement qualify of a path, because of limited performance. We propose a path-finding algorithm using a Maximum peed Dynamic Heuristic to improve quality and reduce a cost of exploring. Proposed method is to use a maximum road speed of appropriate region as dynamic heuristic for path-finding.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.238.1-238.1
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• 2015

2차원 탄소나노재료인 그래핀은 본연의 우수한 물성으로 인하여 전자소자, 에너지 저장매체, 유연성 전도막 등 다양한 분야로의 응용가능성이 제기되었다. 그러나 실제적인 응용을 위해서는 그래핀의 구조적인 결함을 최소화하며, 특성을 자유로이 제어하거나 향상시키는 공정의 개발이 필요하다. 일반적으로 화학적 도핑은 그래핀의 전기적 특성을 제어하는 효율적인 방법으로 알려져 있다. 화학적 도핑의 방법으로는 그래핀을 특정 가스 분위기에서 고온 열처리하거나 활성종들이 존재하는 플라즈마에 노출시킴으로써, 그래핀을 구성하는 탄소원자를 이종원자로 치환하거나 표면에 흡착시켜 기능화 된 그래핀을 얻는 방법 등이 제시되었다. 특히 플라즈마를 이용한 도핑방법은 저온에서 단시간의 처리로 효율적인 도핑이 가능하고, 인가전력, 처리시간 등의 플라즈마 변수를 변경하여 도핑정도를 수월하게 제어할 수 있다는 장점을 가지고 있다. 그러나 플라즈마 내에 존재하는 극성을 띄는 다양한 활성종들로 인하여 그래핀에 구조적인 결함을 형성하여 오히려 특성이 저하될 수 있어 이를 고려한 플라즈마 공정조건의 설정이 필수적이다. 따라서 본 연구에서는 플라즈마에 노출된 그래핀의 Raman 특성을 고찰함으로써 화학적 도핑과 구조적인 결함의 경계를 확립하고 구조결함의 형성을 최소화한 효율적인 도핑조건을 도출하였다. 고품질 그래핀은 물리적 박리법을 이용하여 300 nm 두께의 실리콘 산화막이 존재하는 실리콘 웨이퍼 위에 제작하였으며, 평행 평판형 직류 플라즈마 장치를 이용하여 전극의 위치, 인가전력, 처리시간을 변수로 암모니아(NH3) 플라즈마를 방전하여 그래핀의 Raman 특성변화를 관찰하였다. 그래핀의 구조적 결함 및 도핑은 라만 스펙트럼의 D, G, D', 2D밴드의 강도비와 G밴드의 위치와 반치폭(Full width at half maximum; FWHM)의 변화를 통해 확인하였다. 그 결과, 인가전력과 처리시간이 증가함에 따라 그래핀의 도핑레벨이 증가되고, 이후에는 도핑효과가 없어지고 결함의 정도가 상승하는 천이구역이 존재하며, 이를 넘어서는 너무 높은 인가적력의 처리는 그래핀에 결함을 형성하여 구조적인 붕괴를 야기함을 확인하였다.

• Journal of the Korean GEO-environmental Society
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• v.3 no.4
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• pp.19-27
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• 2002

Prediction of exact soil loss yield has as important engineering meaning as prediction of exact flow measurement in a stream. The quantity of soil loss in a stream should be considered in planning and management of water resources and water quality such as design and maintenace of hydraulic structures : dams, weirs and seawalls, channel improvement, channel stabilization, flood control, design and operation of reservoirs and design of harbors. In this study, the soil loss of Sap-gyo reservoir watershed is simulated and estimated by RUSLE model which is generally used in the estimation of soil loss. The parameters of RUSLE model are selected and estimated using slope map, landuse map and soil map by GIS. These parameters are applied to RUSLE's estimating program. And soil loss under probability rainfall in different frequencies are estimated by recent 30 years of rainfall data of Sap-gyo reservoir watershed.

• Journal of Korean Society of Transportation
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• v.34 no.6
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• pp.510-522
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• 2016

In studies involving public transport, social welfare improvement is simply explained by the increase in public transport demand. However, the increase in the demand for public transport is mostly observed by the change in the frequency of public transport service, and in-vehicle crowding in public transport has not been an object of concern. This study examines and tries to reveal the cause of the changes of the social welfare and in-vehicle crowding of the changing public transport from imposing congestion pricing. We observe that congestion pricing increases in-vehicle crowding in public transport. This predictable phenomenon is more exacerbated in case of not operating bus-only lane. It should be noted that in-vehicle crowding is more increased in suburban, but in First-best toll system it tends to get worse less than it in other congestion pricing systems. We identify that the change of in-vehicle crowding is affected by the change of proximity of the housing to workplace, the number of commuting trips, and unpredictable distortion effect of the congestion charge.