Although concerns about overheating of the franchise industry's market structure continue to be raised, there are few studies that analyze the market structure of the franchise industry and suggest practical use. Most existing studies mainly analyze the market structure of other industries using industrial concentration(HHI) as an indicator of market competition intensity from the perspective of industrial organization theory. This study seeks to present a market structure analysis method that is different from existing methods. Considering practical application, this study presented a method to analyze the market structure that combines industry concentration(HHI) analysis and matrix analysis of the franchise industry. First, the industry concentration(HHI) and operating profit ratio(SMR) of 15 major industries in the franchise industry were analyzed in a time series manner (2014-2019). Second, using industrial concentration and operating profit ratio(SMR) as two variables on the x-axis and y-axis, a two-stage matrix analysis was used to understand the market structure characteristics of 15 industries at a glance. Third, a method of utilizing the matrix analysis results for practical decision-making was presented.
The government is implementing a policy to expand eco-friendly energy as a power source. However, the output of new and renewable energy is not constant. It is difficult to stably adjust the power supply to the power demand in the power system. Therefore, the government predicts day-ahead the amount of renewable energy generation to cope with the output volatility caused by the expansion of renewable energy. It is a system that pays a settlement amount if it transitions within a certain error rate the next day. In this paper, Machine Learning was used to study the prediction of power generation within the error rate.
For the Floating Photovoltaic development project, economic analysis is conducted by predicting the amount of power generation in consideration of climate factors. Among the climate factors, the outside temperature increases the temperature of the module. As a result, the efficiency of the module is reduced. Due to global warming, the outside temperature is rising every year, when estimating the amount of power generation over the next 20 years, a more accurate prediction will be possible only when considering the temperature rise.
Light plays an important role in fruit-body development and morphology during Pleurotus spp. cultivation. To understand the effects of light color on fruit-body properties, we evaluated the fruit-body characteristics of Pleurotus spp. varieties cultivated under blue, red, and purple LED light sources. The main results are as follows: The overall fruit-body shape showed differences depending on the color of the LED light. The fruit-bodies of mushroom cultivated under blue and purple light were generally similar to the mushroom shapes typically produced, while those of mushroom cultivated under green light were abnormally shaped, probably due to the absence of effective light source. The average cap lightness of mushrooms cultivated under blue, green, and purple LED lights was 57.0, 57.4, and 59.4, respectively. The average cap lightness of all varieties except Wonhyeong1ho and Hwang-geumsantari cultivated under the three LED light sources were statistically significantly different (P<0.05). The cap redness varied significantly depending on the LED lighting and variety. Only Gonji7hoM, the cap color mutant of Gonji7ho, showed negative cap redness values under all three LED light sources. Among the eight varieties excluding Gonji7ho, the highest cap redness was observed when cultivated under the blue LED. The average harvest weight of the varieties cultivated under purple, blue, and green LED light were 68.0, 58.3, and 50.1 g, respectively. The yield of Gonji7ho, the mushroom variety with the highest yield, cultivated under blue, green, and purple LED light were 92.8, 77.1, and 98.6 g, respectively. The earliness when grown under the purple, blue, and green LED lights were 5.3, 5.8, and 5.8 days, respectively. Among the varieties, six, three, and two cultivars showed the shortest earliness under the purple, green, and blue LED, respectively. The fruit-body lengths were 66.4, 51.8, and 46.8 mm when cultivated under green, purple, and blue lights, respectively. These results are expected to serve as a foundation for producing mushrooms with traits demanded in the market.
To elucidate how cultivation temperature affected various traits including pileus color, yield and morphology of Pleurotusspp. Main results were as follows. Pileus lightness of all cultivars of Pleurotustested became higher as cultivation temperature increased, while those of Santari, Hwang-geumsantari and Sunjung at 21oC were lower than at 18oC. Redness and yellowness of pileus decreased as cultivation temperature increased; those of chromatic pileus cultivars showed noticeable difference. Yellowness of cultivar with chromatic pileus was higher than that of cultivar with achromatic pileus. Yield was increased as cultivation temperature increased, Wonhyeung 1ho; low temperature favored cultivar showed high yield when it was cultivated at low temperature andno fruiting body at 21oC. Valid number of stipes were generally higher at 18oC, and its correlation coefficient with yield was low. Length and stipe thickness changed consistently (larger and thicker) upon cultivation temperature; the coefficient of determination(R2) 0.514 for lengthof Heuktari and 0.963for stipe thickness of Santari were high. Correlation coefficient of one trait was highly related with multiple traits. In the future, we will conduct research on the changes of expressed genes involved in the pigments for pileus color by RNA expression analysis.
The purpose of this study is to reveal and compare the differences in the types and characteristics of purchase channel journeys of MZ generation consumers. In this study a survey was conducted on the purchase channel journey of 20 women in the MZ generation using the ethnographic method of in-depth interviews and observations. As a result, three purchase channel journeys were identified: mobile, multi-channel, and offline. These were variously subdivided according to the characteristics of the MZ generations. Gen Z’s journey was categorized into types: fashion platform app, Youtube, multi-channel supplement, multi-channel non-planned store visit, offline loyalty store, and impulsive offline store. Gen M’s journey was categorized as: an online community bond, portal site, online loyalty store, multi-channel brand involvement, multi-channel efficiency, a multi-channel conversion, offline efficiency and offline task. The difference in mobile journey between generations was found in the time and length of the purchase. Gen M recognized both online and offline search processes to be tiring, while Gen Z enjoyed the search process using the online path. In the offline journey Gen Z began with their own intention to purchase, while Gen M sometimes recognized that purchasing fashion products necessary for work was a cumbersome task.
본 연구는 고속스핀에코 기법을 이용한 MRI 검사에서 영상 변수가 전자파 흡수율(SAR)과 온도 증가에 미치는 영향을 평가해 보고자 하였다. 이를 위해 인체 등가 조직 팬텀을 제작하였고 같은 조건에서 재위상화 RF의 FA와 ETL을 증가시키 며 MRI 검사를 시행하였다. SAR는 장비에서 계산된 두부 SAR값을 사용하였고 팬텀의 온도 변화는 양성자 공명 주파수를 이용해 계산하였다. 실험 결과, FA를 60°에서 180°까지 증가시켰을 때 SAR는 약 8배까지 상승하였고 팬텀의 온도 상승의 폭은 약 2.8배(0.21°-0.599°) 증가하였다. 그리고 다중 회귀 분석 결과, FA는 SAR와 온도 상승의 관계에서 표준화 계수 가 각각 0.935, 0.741로 나타나 높은 상관관계를 보였다. ETL은 15에서 30까지 증가시켰을 때 SAR는 약 2배 증가하였 다. 하지만 팬텀의 온도 상승 폭은 오히려 39.2%(0.53°-0.303°) 감소하였다. 다중 회귀 분석 결과에서도 ETL은 SAR의 관계에서 표준화 계수가 0.741로 양의 상관관계를 보였지만 온도 상승의 경우 표준화 계수가 –0.482로 나타나 음의 상관 관계가 있었다. 이는 ETL이 15에서 30까지 증가함에 따라 검사 시간이 약 43% 짧아져 전자파의 노출 시간이 감소한 것이 원인이 될 수 있다. 결국, FSE 기법을 이용한 MRI 검사에서는 재위상화 FA는 최소화하고 기준 SAR 범위 내에서 ETL을 최대로 적용하면 전자파로 인한 온도 상승을 최소화할 수 있어 환자 안전을 증진 시킬 수 있을 것으로 기대한다.
Metal-organic frameworks (MOFs) are widely used in various fields because they make it easy to control porous structures according to combinations of metal ions and organic linkers. In addition, ZIF (zeolitic imidazolate framework), a type of MOF, is made up of transition metal ions such as Co2+ or Zn2+ and linkers such as imidazole or imidazole derivatives. ZIF- 67, composed of Co2+ and 2-methyl imidazole, exhibits both chemical stability and catalytic activity. Recently, due to increasing need for energy technology and carbon-neutral policies, catalysis applications have attracted tremendous research attention. Moreover, demand is increasing for material development in the electrocatalytic water splitting and metal-air battery fields; there is also a need for bifunctional catalysts capable of both oxidation/reduction reactions. This review summarizes recent progress of bifunctional catalysts for electrocatalytic water splitting and metal-air batteries using ZIF-67. In particular, the field is classified into areas of thermal decomposition, introduction of heterogeneous elements, and complex formation with carbonbased materials or polyacrylonitrile. This review also focuses on synthetic methods and performance evaluation.
We investigate the effect of phosphorous content on the microstructure and magnetic properties of Fe83.2Si5.33-0.33xB10.67-0.67xPxCu0.8 (x = 1–4 at.%) nanocrystalline soft magnetic alloys. The simultaneous addition of Cu and P to nanocrystalline alloys reportedly decreases the nanocrystalline size significantly, to 10–20 nm. In the P-containing nanocrystalline alloy, P atoms are distributed in an amorphous residual matrix, which suppresses grain growth, increases permeability, and decreases coercivity. In this study, nanocrystalline ribbons with a composition of Fe83.2Si5.33-0.33xB10.67- 0.67xPxCu0.8 (x = 1–4 at.%) are fabricated by rapid quenching melt-spinning and thermal annealing. It is demonstrated that the addition of a small amount of P to the alloy improves the glass-forming ability and increases the resistance to undesirable Fex(B,P) crystallization. Among the alloys investigated in this work, an Fe83.2Si5B10P1Cu0.8 nanocrystalline ribbon annealed at 460oC exhibits excellent soft-magnetic properties including low coercivity, low core loss, and high saturation magnetization. The uniform nanocrystallization of the Fe83.2Si5B10P1Cu0.8 alloy is confirmed by high-resolution transmission electron microscopy analysis.
기업의 경쟁우위를 결정하는 핵심 요소로서 기술혁신의 중요성이 강조되는 가 운데, 혁신의 지속 여부 또한 중요한 연구 대상이 되고 있다. 혁신 지속(innovation persistence)은 기업의 혁신이 일회성으로 그치지 않고 지속적으로 이루어지고 있는지를 나 타내는 개념이다. 혁신 연구에 사용되는 자료는 대부분의 국가에서 횡단면 조사로 수행됨에 따라 종단적인 지속 현상을 다룬 연구는 드문 편이며, 특히 국내의 혁신조사 자료를 이용하 여 혁신 지속 현상을 살펴본 연구는 거의 없다. 본 연구는 문헌 연구를 바탕으로 기업의 혁신 지속에 대한 개념과 특징을 고찰하는 한편, 우리나라 기업의 기술혁신 지속 현황 및 특성에 대한 실증 분석을 수행하였다. 분석을 위해 2012년부터 2018년까지 격년으로 수행된 한국기 업혁신조사 자료를 바탕으로, 복수관측된 3,379개 기업에 대한 불균형 패널자료를 구성하였 다. 기술혁신의 지속 현상을 살펴본 결과, 지속적인 혁신이 관측되는 기업은 전체 중 일부(혁 신성과에서는 10~12%, 혁신활동에서는 15~17%)에 불과하였으며, 오히려 비혁신의 지속 현 상이 두드러지는 것으로 나타났다(약 52~57%). 또한 혁신성과보다는 혁신활동의 지속 현상이 강한 것으로 확인되었다. 이 외에도 제품혁신이 공정혁신보다, 내부 R&D가 공동/외부 R&D보다 지속성이 높게 나타나는 등 세부 유형에 따른 지속 현상의 특징들을 도출할 수 있 었다. 그리고 혁신 지속의 영향요인 식별을 위해 추가적으로 로짓분석을 수행한 결과, 급진 적 혹은 점진적 제품혁신이 다음 시기에서 혁신이 지속되게 하는 가장 영향력 높은 요인인 것으로 나타났다. 본 연구에서 구축한 패널자료는 원시자료의 한계로 인해 표본 선택 편의가 존재하기 때문에, 분석 결과의 지나친 일반화는 경계해야 한다. 그럼에도 불구하고 한국 기 업을 대상으로 기술혁신 지속 현상을 종합적으로 분석한 초기연구로서 의의가 있으며, 후속 연구의 시발점이 될 것으로 기대된다. 향후 공식적인 패널자료의 구축 및 개선된 방법론 등 을 통해, 혁신 지속 관련 발전된 연구 결과가 도출되기를 기대한다.
NDF (No Defect Found) is a phenomenon in which defects have been found in the manufacturing, operation and use of a product or facility, but phenomenon of defects is not reproduced in the subsequent investigation system or the cause of the defects cannot be identified. Recently, with the development of the fourth industrial revolution, convergence of hardware and software technologies in various fields is spreading to products such as aircraft, home appliances, and mobile devices, and the number of parts is increasing due to functional convergence. The application of such convergence technologies and the increase in the number of parts are major factors that lead to an increase in NDF phenomena. NDF phenomena have a significant negative impact on cost, reliability, and reliability for both manufacturers, service providers and operators. On the other hand, due to the nature of NDF phenomena such as difficult and intermittent cause identification and ambiguity in judgment, it is common to underestimate the cost of NDF or fail to take appropriate countermeasures in corporate management. Therefore, in this paper, we propose a methodology for estimating NDF costs by the PAF model which is a quality cost analysis model and ABC (Activity Based Costing) technique. The methodology of this study suggests a detailed procedure and the concept to accurately estimate the NDF costs, using ABC analysis, accounting system information, and IT system data. In addition case studies have validated the methodology. We think this could be a valid methodology to refer to when estimating the cost of other parts. And, it is meaningful to provide important judgment information in the decision-making process based on quality management and ultimately reduce NDF costs by visualizing them separately by major variable factors.
We investigated the distributions of airborne radon concentration on the platforms of the stations of Seoul Metro by the underground depth of each subway line, and explored the correlation between the radon concentration and the depth and geological conditions around each underground station. The measurements of radon levels were performed in 254 subway stations within Seoul Metro Lines 1 to 8 using the passive sampler (RADUET). Radon concentration data from 2007 to 2017, as well as the depth of each subway station were obtained from the Seoul Metro corporation. The geological information of each subway station were purchased from the Korea Institute of Geoscience and Mineral Resources. Student t-test and correlation analyses were performed to compare the levels of radon by the depth of subway stations, and to investigate the association of radon levels based on geological information. The geometric mean concentration of the all subway stations was 27.9 Bq/m3 ( range, 3 . 7Bq/ m3~124.0 Bq/m3). The depth of Lines 5-8 (geometric mean, –20.3 m) was significantly deeper by about 50% or more than that of Lines 1-4 (–13.1 m) (P<0.01). The radon levels increased significantly in deeper depths and as the number of Lines increased (P<0.05). A significant higher mean concentration of radon above the igneous rock (33.0 Bq/m3) was observed, comparing to that of non-igneous rock (27.5 Bq/m3) (P<0.00001). Our findings indicate that the deeper the subway is built or the more it is constructed on the granite area, the more careful management, including frequent ventilation and measurement monitoring, is necessary.
디지털 게임은 인터넷과 정보통신기술의 발달로 인하여 점점 더 다양해지고 복잡해지고 있다. 기존의 게임분류를 넘어서 플레이어 관점 디지털게임의 특성을 반영한 새로운 게임 분류가 필요하다. 현재의 게임 분류들은 게임공급자의 입장에서 장르를 구분하는 일반적인 분류들이다. 본 연구에서는 디지털 게임 플레이어들이 게임을 할 때 활용하는 개인 마음속의 구성개념(personal construct)들을 분석하여 새롭게 나타나고 있는 디지털 게임들의 속성들을 찾아냈다. 개인 마음속의 구성개념들을 찾아내기 위하여 레퍼토리 그리드 인터뷰들을 수행하였다. 레퍼토리그리드방법은 사람들이 마음속에 가지고 있는 구성개념들을 찾아내기 위한 연역적인 연구 방법론이다. 이 방법론을 통하여 22명의 플레 이어들로부터 1,669개의 진술문들을 수집했다. 전문가 포커스 그룹을 통해서 진술문들에서 29개의 특성차원들을 찾아내었고 이를 12개의 카테고리, 그리고 게임 상태, 플레이어 구조, 물리적 환경, 그리고 게임 플로우의 4가지 메타 카테고리로 분류할 수 있었다. 기 존의 게임 분류들과 비교하여 볼 때 29개의 차원중에서 13개는 이전에 없던 새로운 특성 차원이었다. 결과적으로 새롭게 나타나는 디지털게임의 속성들은 기존의 게임들의 속성들과는 다른 것을 알 수 있었다. 본 연구에서 도출한 차원들과 카테고리들은 앞으로 디지털 게임을 개발 디자인하고 평가하는데 있어서 가이드라인으로 활용할 수 있다.
본 연구는 두경부의 자기공명 역동적(dynamic) 혈관조영술(DCE-MRA)에서 조영제(1.0 mol/ℓ)와 생리식염수의 희석 주입 비율에 따른 신호강도 차이를 비교 분석하였다. 연구 방법으로는 3.0 T MRI 장치에서 자동주입기를 이용하여 조영제와 생리식염수의 희석주입 비율(조영제:생리식염수)을 10:0 (1000 mmol/ℓ, 조영제 원액), 7:3 (700 mmol/ℓ), 5:5 (500 mmol/ℓ)로 3가지 군으로 하였다. 주입 조건으로는 오른팔 정맥으로 주입 속도 3.0 ㎖/sec으로 하였고 용량은 0.1 ㎖/㎏으로 하였다. 신호강도 측정은 동맥혈관 7 부위와 정맥혈관 2 부위로 하였고 역동적 영상에서의 측정 시기는 정맥이 침범하기 직전의 순수 동맥기, 최고신호 동맥기, 최고신호 정맥기로 구분 하였다. 연구 결과 최고신호 동맥기의 횡정맥동을 제외한 모든 측정 시기의 10:0 (1000 mmol/ℓ), 7:3 (700 mmol/ℓ), 5:5 (500 mmol/ℓ) 순서로 신호강도가 증가하였다(p<0.01). 따라서 두경부의 DCE-MRA에서 조영제와 생리식염수의 5:5 희석주입을 통하여 최고의 신호강도를 구현할 수 있고 최적의 영상을 얻을 수 있다.