• 한국식품영양학회지
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• 제33권6호
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• pp.702-709
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• 2020

The purpose of this study was to evaluate microbiological contamination of knives and cutting boards in child-care centers. Materials used in this study were swabbed of cutting boards and knives (blade, handle of knife, and joint of handle and blade) in 129 child-care centers. Mean values of total aerobic bacteria of swabs of knives and cutting boards were 1.7±0.7 log cfu/100 ㎠ and 1.7±0.9 log cfu/100 ㎠, respectively. Contamination levels of coliform bacteria from knives and cutting boards were 1.5±0.6 log cfu/100 ㎠ and 1.7±0.8 log cfu/100 ㎠, respectively. Comparing microbiological contamination levels of knives and cutting boards according to type and size of child-care centers, there was no significant difference. Bacillus cereus was detected in knife handles and cutting boards. Diarrhea-type toxin gene (entFM) was detected in B. cereus isolates. Antibiotic resistance tests showed that B. cereus was resistant to β-lactam antibiotics. To reduce microbiological contamination levels of knives and cutting boards in child-care centers and prevent food poisoning from bacteria contamination, continuous education by children's food-service management center is needed for sterilization and disinfection of knives and cutting boards.

• Clinical Endoscopy
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• 제57권1호
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• pp.36-47
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• 2024

Background/Aims: Scissor-type endoscopic submucosal dissection (ST-ESD) knives can reduce the adverse events associated with ESDs. This study aimed to compare ST-ESD and non-scissor-type (NST)-ESD knives. Methods: We identified ten studies that compared the performance characteristics and safety profiles of ST-ESD and NST-ESD knives. Fixed- and random-effects models were used to calculate the pooled proportions. Heterogeneity was assessed using the I² test. Results: On comparing ST-ESD knives to NST-ESD knives, the weighted odds of en bloc resection was 1.61 (95% confidence interval [CI], 0.90-2.90; p=0.14), R0 resection was 1.10 (95% CI, 0.71-1.71; p=0.73), delayed bleeding was 0.40 (95% CI, 0.17-0.90; p=0.03), perforation was 0.35 (95% CI, 0.18-0.70; p<0.01) and ESD self-completion by non-experts was 1.89 (95% CI, 1.20-2.95; p<0.01). There was no heterogeneity, with an I² score of 0% (95% CI, 0%-54.40%). Conclusions: The findings of reduced odds of perforation, a trend toward reduced delayed bleeding, and an improvement in the rates of en bloc and R0 resection with ST-ESD knives compared to NST-ESD knives support the use of ST-ESD knives when non-experts perform ESDs or as an adjunct tool for challenging ESD procedures.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.323-327
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• 1995

A new air knife system for coating thickness control in hot dip galvanizing process had been developed and installed on the CGL in Pohang Steel Works, POSCO. This new system consists of air knives with remotely adjustable nozzle slot and an automatic control system which can control both longitudinal and traverse coating deviations. Based on the optimal control algorithm, a traverse coating deviation control was designed. The controller controls the lip profile of the air knives with flexible structure according to the deviation of coating weight. From the measured values which are dependent on the strip width, the lip gaps are calculated with optimal algorithm and the model of the coating deviation. Time delay between knives and a coating thickness gauge is solved by the Smith Predictor.

• Journal of Biosystems Engineering
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• 제20권1호
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• pp.13-21
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• 1995

This study was conducted to investigate the cutting mechanism of reciprocating knife of combine harvester. The cutting operation of reciprocating knife with the arrangement of the low-cutting and the double-cutting was demonstrated through cutting pattern diagram which was drawn by computer graphics. Various kinds and dimensions of reciprocating knives were analyzed using the developed program. The results are summarized as follows (1) The low-cutting type reciprocating knife was represented similar cutting characteristics to the standard type, but the maximum stalk-deflection was decreased as 1/2 level of the standard type. And the first ledger plate should be designed shorter than the second ledger plate. (2) The bunching area and the maximum stalk-deflection for the double cutting knife almost were not changed since cutting velocity ratio of 0.6, but the secondary cut were occurred at ratio of 0.8 and increased rapidly over these ratio. (3) The double cutting knife was recommended for the high speed combine, because its bunching area and the maximum stalk-deflection were decreased as 1/2 level of the standard type. (4) In order to maintain the proper cutting mechanism characterized by the bunching area, the maximum stalk-deflection and the secondary cutting length etc., the adequate cutting velocity at forward speed of 0.5㎧ to 1.2㎧ was from 0.3㎧ to 0.96㎧ for the double cutting knives.

• 대한수사과학회지
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• 제1권2호
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• pp.31-43
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• 2006

최근 살인사건의 실태를 보면 칼을 이용한 살인사건이 가장 많다. 살인을 음모하고 예견된 살인도 있지만, 순간적인 분노로 인한 우발적으로 저질러지기도 한다. 우발적인 범행에서 주변 가까이에 있는 가정용 칼을 범행에 사용하는 경우가 많지만 일상생활에서 칼의 위험성을 인식하는 경우가 드물다. 이에 전국에서 발생하는 살인사건의 범행방법 중 칼에 의한 범행에서 동기 분석과 함께 살해에 사용한 칼의 종류를 분석하였다. 그리고 칼에 대한 인식을 알아보고자 성인 남녀 500명을 대상으로 가정용 칼에 대한 21항목의 설문조사를 실시하였다. 그 결과를 일반 가정에서 사용하는 칼의 대부분이 칼끝이 날카로워 사실상 범행에 사용하기가 용이하였다. 그렇기 때문에 범인들이 칼을 휴대하기보다는 범행 장소에서 칼을 쉽게 구하여 범행에 사용하는 경우가 많다. 그리고 우발적인 살인의 경우에도 주방이나 식탁 또는 거실에서 칼을 쉽게 구할 수 있기 때문에 살인 사건이 더욱 빈발할 수 있다. 일반인의 칼에 대한 인식에서 칼의 위험도를 낮추기 위하여 칼끝을 둥글게 하자는 여론은 매우 높은 결과로 나타나지만 실제로 칼의 위험성에 대한 인식이 낮았다. 따라서 가정이나 가까운 사이에서 우발적 충동적인 살인을 예방하기 위하여 생활도구로 사용하는 칼도 위험한 물건으로 분류하여 인식전환과 함께 칼의 제작과 판매에 있어서 적절한 규제가 필요하다고 생각한다. 칼에 대한 인식을 새롭게 하여 가정에서 칼의 보관과 잠금장치의 필요성에 대한 홍보가 절실하다고 생각한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.506-512
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• 1997

Ultrasonic knives have been successfully used for the surgery of many medical fields. However, the conventional ultrasonic knives for surgical operation cannot be controlled its resonant frequency. So if the material to cut has different characteristic impedance then different ultrasonic knife will be needed. Because the optimum driving frequency of ultrasonic knife is different by characteristic impedance of material. In this work, using a frequency variable ultrasonic transducer made of multi-layered PZT vibrator, a frequency controllable ultrasonic knife will be suggested. The design and computation principles will be also derived. For this work, firstly, the characteristics of this ultrasonic knife will be analyzed by transmission line model equivalent circuit, and the free admittance characteristics and vibrational velocity distributions will be obtained. Secondly, we will design and make the frequency controllable electrical oscillator for driving this ultrasonic knife.

• 한국식품영양과학회지
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• 제39권11호
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• pp.1719-1723
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• 2010

창원시 소재 단체급식소 4개소에서 사용하는 칼($12\;cm^2$), 도마($100\;cm^2$), 고무장갑(손바닥과 손가락 사이)의 표면을 대상으로 ATP Luminometer와 일반세균수용 건조필름을 이용한 미생물 배양법을 함께 적용하여 ATP(RLU)와 APC (CFU)을 측정하였다. 통계분석 결과, 3가지 조리도구 모두에서 ATP(RLU)와 APC(CFU) 간에 유의적인 양의 상관성이 존재하였다. 각 도구별 상관계수는 칼 0.84(p<0.001), 도마 0.79(p<0.001), 고무장갑 0.78(p<0.001)로 나타났다. 본 실은 단체급식 현장에 적합한 ATP Luminometer 가이드라인을 설정하기에 앞서 실시간적인 표면 위생 모니터링 도구로서의 사용 적합성을 살펴 본 예비실험이며, 도출된 회귀식을 이용하여 도구별 ATP(RLU) 가이드라인을 설정하고 검증할 예정이다.

• 보건교육건강증진학회지
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• 제23권3호
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• pp.53-63
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• 2006

Objectives: The purpose of this study was to analyze the effects of microbe inspections on the hygienic improvement of school food service systems. Methods: Thirty-three school food service systems in Incheon metropolitan city participated in the study from Sep. 2004 to Apr. 2005. Major items of microbe inspections were cutting boards, knives, kitchen towels, and kitchen staff's hands. The Rodac plate and hand plate were used to measure the surface contamination level of germs such as Staphylococcus aureus, Vibrio species, Salmonella species and E. coli. Results: This study compared the results of the inspections in Sep. 2004 and Apr. 2005. The surface contamination level of Staphylococcus aureus and Vibrio species on the knives and kitchen towels had significantly improved. However, the surface contamination level of E. coli on the hands of the kitchen staff had worsened. Conclusions: This study showed that microbe inspections could control the hygienic level of the school food service systems. In the future, microbe inspections should be actively used to improve sanitary conditions in the school lunch system.

• 한국식품조리과학회지
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• 제19권2호
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• pp.231-240
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• 2003

The purpose of this study was to evaluate the effect of implementing the HACCP system on foodservice establishments. At first, the hygienic conditions were measured by microbiological hazard analyses of the cooking utensils and working areas. In order to solve the detected problems, the HACCP system was implemented, after what was considered a sufficient settlement period following the initial assessment, then microbiological verification was performed again. In relation to the cooking utensils and equipment(kitchen knives, cutting boards, knives for shredding vegetables, refrigerators, baskets, barts, working tables, preparation tables, tungs, dish-clothes and drains) the microbiological inspection on the Total Plate Count, Coliforms, Staphylococcus aureus and Listeria monocytogenes, were conducted with regard to the working areas(working tables, preparation tables, seasoning's shelves, serving tables, drinking water tables, refrigerators, storage rooms and dining tables), the Total Plate Count and Fungi were also examined. According to the microbiological hazard analyses there were many problems, especially with cutting boards, baskets, barts, dish-clothes and sinkballs. However, by introducing the HACCP system, the microbiological hazard levels were able to be controlled and lowered, and the total aerial bacteria in the working areas of the foodservice establishments were detected at levels below 6 CFU/plate.

• Corrosion Science and Technology
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• 제23권3호
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• pp.228-234
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• 2024

Zinc wiping is a phenomenon used to control zinc-coating thickness on steel substrate during hot dip galvanizing by equipment called air knife. Uniformity of zinc coating weight in length and width profile along with surface quality are most critical quality parameters of galvanized steel. Deviation from tolerance level of coating thickness causes issues like overcoating (excess consumption of costly zinc) or undercoating leading to rejections due to non-compliance of customer requirement. Main contributor of deviation from target coating weight is dynamic change in air knives equipment setup when thickness, width, and type of substrate changes. Additionally, cold coating measurement gauge measure coating weight after solidification but are installed down the line from air knife resulting in delayed feedback. This study presents a coating weight control model (Galvantage) predicting critical air knife parameters air pressure, knife distance from strip and line speed for coating control. A reverse engineering approach is adopted to design a predictive, prescriptive, and descriptive model recommending air knife setups that estimate air knife distance and expected coating weight in real time. Implementation of this model eliminates feedback lag experienced due to location of coating gauge and achieving setup without trial-error by operator.