This study examined the effects of startup firm's knowledge assets on the effectiveness of their sales strategies, efficiency of sales activities, and management performance, after categorizing these assets into customer knowledge assets and technology knowledge assets. Furthermore, the moderating effects of promotion focus by CEOs and sales managers of startup firms were analyzed. For the analysis, dyadic questionnaire surveys were conducted targeting the CEOs and sales managers of startup firms established at the Gyeongnam Technopark and the KAIST Technology Business Incubation Center in Korea. Hypotheses were verified through structural equation modeling, and moderating effects were identified through ANOVA. CEO's customer knowledge asset strengthened their effectiveness of sales strategies, and sales manager's technology knowledge asset strengthened the efficiency of their sales activities. Also, CEO's effectiveness of sales strategies and sales manager's efficiency of sales activities have been found to enhance startup firm's management performance. Meanwhile, the moderating effect of promotion focus strengthened CEO's effectiveness of sales strategies through CEO's customer knowledge asset and interaction as CEO's promotion focus level increased, but promotion focus of sales managers did not have any significant interaction effect. This study provides implications by offering empirical evidence on startup firms with regard to knowledge assets.

Background : Recent climate change has also affected the biological season for plants. There are various studies on this, but most of them are studying horticultural crops. The purpose of this study was to investigate the timing of flowering in different regions and to predict the flowering time of Schisandra chinensis (Turcz.) Baillon. using meteorological data. Methods and Results : The flowering time and cultivation area of Schisandra chinensis were searched and surveyed by the Internet data and Annual research report of the RDA. Accumulated temperature and Growing degree day at 0℃, 5℃, 10℃ or more and Cumulative hours of sunshine at 0℃ or more to the cultivation area and flowering period of irradiated Schisandra chinensis were calculated from meteorological data of KMA (Korea. Meteorological Administration) and calculated using Excel, respectively. statistical analysis was performed using Excel. The data collected were 15 research reports and 20 internet surveys, but it was difficult to use statistical significance due to the high coefficient of variation. The 5-year Suwon data and the 3-year data of Jinan were used in the study report data relatively close to the meteorological stations. Conclusion : Results of statistical analysis. The flowering time of Schisandra chinensis is the time when Accumulated temperature of 0℃ or more [Σ (daily average temperature > 0℃)] becomes 650℃ and the Growing degree day of 0℃ or more { Σ [ (day maximum temperature + day minimum temperature) / 2 > 0℃ ] } was 670℃. The coefficient of variation was 6.5% and 6.2%, respectively.

Background : Ginseng (Panax ginseng C.A. Meyer) is one of the most important medicinal plants in Korea, but its yields are often reduced by a variety of root pathogens. The root rot of ginseng is a destructive soil-borne disease caused by Cylindrocarpon destructans (teleomorph: Ilyonectria radicicola). To monitor contamination with C. destructans in ginseng harvested in 2015 were sampled from 57 different growing fields. The spore number of C. destructans was quantified by use of a specific primers and selective media (radicicol) in soils of ginseng fields. Methods and Results : The ginseng samples were surface-sterilized and placed on potato dextrose agar plates for 7 day incubation at 20℃. Emerging fungal colonies were counted primarily based on colony and conidia morphology. Further species level identification was confirmed by ITS rDNA sequencing. For quantification of the soil-borne C. destructans, the genomic DNA was extracted from the soil using a NucleoSpin soil kit (MN, Germany). Density of C. destructans was determined by species specific real time PCR (qPCR). The qPCR was completed by running a melting curve analysis. Conclusion : The C. destructans associated with root rot disease of ginseng were detected in more than 60% in pyeongtaek-1, pochenon-1, jecheon-1, chungju-1 and jinan-4. As results of the study, the correlation between pathogen density and identification clearly clarified in the soil.

이 연구의 목적은 개착식 전력구 콘크리트에 발생하는 부등건조수축에 의한 균열특성을 파악하고, 수축저감제 혼입에 따른 건조수 축균열특성을 분석하는데 있다. 따라서 이 연구에서는 전력구 박스형 콘크리트 구조물의 부등건조수축에 의한 균열특성을 파악하기 위하여 세 가지 주요영향인자를 고려한 수치해석과 수치해석을 한 결과와 실제 전력구 타설을 하여 측정한 차이를 확인해 보았다. 본 연구로부터 건조 수축 시험체에 대한 건조수축량을 산정에 대한 해석 기법을 개발하였으며, 실제 전력구 타설 실험을 통해 종방향 및 횡방향 균열발생 가능성을 입증 하였다. 전력구 실증시험체 건조수축량 수치해석 결과, 균열저감 콘크리트 배합의 경우 종방향 및 횡방향 응력에 있어 일반배합에 비해 40~50%정도의 현저한 감소를 보이며, 이에 따라 균열저감 콘크리트를 전력구에 적용하였을 경우 현저한 균열감소 효과를 보일 것으로 예측된다.

이 연구의 목적은 개착식 전력구 콘크리트에 발생하는 부등건조수축에 의한 균열특성을 파악하고, 그 제어방법을 제시하는데 있 다. 건조수축균열은 콘크리트 내부의 수분확산계수의 영향을 크게 받으며, 수분확산계수는 콘크리트 내부에서의 수분이동속도를 결정하는 주요인자이다. 수분확산계수와 더불어 콘크리트 표면의 표면계수와 외부의 상대습도는 콘크리트 내부에서 외부로의 수분이동에 영향을 미친 다. 따라서 이 연구에서는 전력구 박스형 콘크리트 구조물의 부등건조수축에 의한 균열특성을 파악하기 위하여 세 가지 주요영향인자를 고려 한 수치해석을 수행하였다. 수치해석 결과, 수분확산계수와 표면계수가 증가할수록 상부슬래브의 부등건조수축에 의한 균열발생시점이 빨라 지며, 세 가지 요인 중에 콘크리트의 부등건조수축에 의한 균열발생 특성에 가장 큰 영향을 미치는 것은 외기습도인 것으로 나타났다. 이 연구 결과를 분석한 결과, 개착식 전력구 시공시에 콘크리트 타설 후 표면보습이나 살수양생과 같이 외기습도를 증가시키는 것이 부등건조수축에 의한 균열제어에 가장 효과적인 것으로 판단되며, 콘크리트 재료적 측면의 균열저감방법으로 수분확산계수와 표면계수를 결정하는 콘크리트 의 배합이나 재료특성을 적절히 선정함으로써 균열의 진전속도나 발생시점을 제어할 수 있을 것으로 판단된다.

Carbonation is one of the most critical deterioration phenomena to concrete structures exposed to high CO2 concentration, sheltered from rain. Lots of researches have been performed on evaluation of carbonation depth and changes in hydrate compositions, however carbonation modeling is limitedly carried out due to complicated carbonic reaction and diffusion coefficient. This study presents a simplified carbonation model considering diffusion coefficient, solubility of Ca(OH)2, porosity reduction, and carbonic reaction rate for low concentration. For verification, accelerated carbonation test with varying temperature and MIP (Mercury Intrusion Porosimetry) test are carried out, and carbonation depths are compared with those from the previous and the proposed model. Field data with low CO2 concentration is compared with those from the proposed model. The proposed model shows very reasonable results like carbonation depth and consuming Ca(OH)2 through reduced diffusion coefficient and porosity compared with the previous model.

최근 전력 전송을 위해 지하에 건설되는 전력구 구조물이 증가함에 따라, 이러한 구조물의 수명 연장은 매우 중요한 문제로 대두되고 있다. 현재까지의 현장 및 실험결과들은 콘크리트 내부의 철근이 콘크리트 피복의 탄산화 현상에 의해 부식될 수 있음을 보이고 있으며,이러한 탄산화에 의한 철근의 부식은 구조물 주변의 높은 이산화탄소 농도에 의해 빈번히 발생할 가능성을 내포하고 있다. 따라서, 본 연구에서는 실제 전력구 현장에서의 철근 깊이와 탄산화 깊이를 측정한 결과를 바탕으로 우리나라의 전력구 콘크리트 구조물에 대한 탄산화위험도를 평가하였다. 현장 데이터를 기반으로 철근 주변에서의 탄산화에 의한 전력구의 사용수명을 평가하였으며, 이를 위해 확률론적 방법인 몬테카를로 기법을 적용하였다. 또한 균열을 유발한 시험체에 대한 탄산화 촉진 실험을 수행하여, 그 실험결과를 바탕으로 균열을 고려한 경우의 전력구의 사용수명을 수치적으로 평가하고 분석하였다.

The aim of this study was to isolate chicken feather-degrading bacteria with high keratinolytic activity and to investigate cultural conditions affecting keratinolytic enzyme production by a selected isolate. A chicken feather-degrading bacterial strain CH3 was isolated from poultry wastes. Isolate CH3 degraded whole chicken feather completely within 3 days. On the basis of phenotypical and 16S rDNA studies, isolate CH3 was identified as Bacillus thuringiensis CH3. This strain is the first B. thuringiensis described as a feather degrader. The bacterium grew with an optimum at pH 8.0 and 37℃, where maximum keratinolytic activity was also observed. The composition of optimal medium for keratinolytic enzyme production was feather 0.1%, sucrose 0.7%, casein 0.3%, K2HPO4 0.03%, KH2PO4 0.04%, MgCl2 0.01% and NaCl 0.05%, respectively. The keratinolytic enzyme had a pH and temperature optima 9.0 and 45℃, respectively. The keratinolytic activity was inhibited ethylenediaminetetraacetic acid, phenylmethylsulfonyl fluoride, and metal ions like Hg2+, Cu2+ and Zn2+. The enzyme activated by Fe2+, dithiothreitol and 2-mercaptoethanol.

The removal of nitrogen compounds from a wastewater is essential and it is often accomplished by biological process. An aerobic nitrate-removing bacterium was isolated from a municipal sewage treatment plant and soil. On the basis of its morphological, cultural and physiological characteristics and 16S rRNA sequencing data, this strain was identified as Pseudomonas fluorescens, and named as P. fluorescens K4. The optimal conditions of the initial pH and temperature of media for its growth were 7.0~8.0 and 30℃, respectively. P. fluorescens K4 was able to remove 99.9% of nitrate after 24 h in a culture. The strain could grow with a nitrate concentration up to 800 mg/l and was able to remove 99.9% of nitrate after 104 h of incubation. The optimal electron donor was sodium citrate for a nitrate removal. The strain K4 showed a capability of a complete nitrate removal when the initial C/N ratio was 1.0. An effect of the initial seed concentration was observed for a cell of 10% (v/v) for a nitrate removal. Especially P. fluorescens K4 could completely remove 200 mg/l ammonium for 3 days.