• Journal of the Korea Computer Industry Society
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• v.2 no.2
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• pp.229-234
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• 2001

The flowmeter is being widely used from water flowmeter for homeuse to many other applications for industry such as petrochemistry. In particular, a wireless automatic flowmeter is highly in demand. This paper suggests a gearwheel wireless automatic flowmeter using PICBASIC which can be simply implemented for manufacturing. It is confirmed by experiment that the automatic flowmeter using by a wireless chip works well in a local area within 300 meters.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.375-381
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• 2020

This study assessed the contamination levels of total aerobic bacteria, fungi, coliforms, Escherichia coli, Bacillus cereus, and Staphylococcus aureus and qualitative analysis of Salmonella spp. and Listeria monocytogens in six raw materials (beef, bean sprout, Chinese cabbage, king oyster mushroom, Korean cabbage, and sweet pumpkin) of home meal replacement (HMR) Shabu-Shabu meal kit distributed in markets. The total aerobic bacteria, fungi, and coliforms were detected as 3.98-6.50, 2.78-3.52, and 2.02-3.28 log CFU/g, respectively. Especially, beef was highly contaminated with total aerobic bacteria (6.50 log CFU/g) and coliforms (3.28 log CFU/g). Over 5 log CFU/g of total aerobic bacteria were also detected in bean sprout, Chinese cabbage, and sweet pumpkin. Less than < 2 log CFU/g of coliforms were detected in all vegetables. E. coli was not detected in any of the six samples (ND: < 1 log CFU/g). S. aureus was detected as 1.33-1.71 log CFU/g in most samples but it was not detected in beef and Korean cabbage. B. cereus was assessed as 1.15-2.01 log CFU/g in most samples but it was not detected in Korean cabbage. L. monocytogenes was qualitatively detected as 25-50% in most samples except for king oyster mushroom. Salmonella spp. were not qualitatively detected in any of the six samples. The microbial contamination levels determined in the current study may be potentially used as the basic data to execute microbial risk assessments of HMR foods such as Shabu-Shabu meal kit.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.44-44
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• 1999

저진공(1 kPa~ 100 kPa)은 대기압 측정, 비행고도, 기체의 온도 측정, 질량의 부력 보정, 레이저의 굴절률 측정등에 사용되는 영역으로 과학적 중요성을 갖고 있다. 또한 대기압 이상의 압력 측정과 고진공 측정의 경계적 역할도 수행하고 있어 압력 표준기의 국제 비교에 필수적으로 권장되는 역역이다. 이 영역에 주로 사용되는 압력 표준기는 수은 압력계(Mercury manometer)와 분동식 압력계(Deadweight piston gauge or Pressure)가 있다. 이들은 이동이 불편하거나 불가능하므로 표준기의 국제 비교에 사용되는 전달 표준기로는 보다 이동이 간편한 탄성 압력계인 CDG(Capacitance diaphragm Gauge)가 있다. 이 게이지는 반도체 산업의 공정 제어용으로도 많이 사용되고 있다. 그러나 게이지와 함께 사용되는 컨트롤러의 부피가 크고 무거우며 영점 이동이 커서 측정때 마다 재조정하여야 하는 단점이 있다. 본 논문에서는 이 같은 단점을 극복하기 위해 수정빔 진동형 진공 센서를 잔달 표준기로 사용하는 것에 대한 연구를 수행하였다. 수정빔 진동형 압력 센서는 수정빔으 공진주파수가 스트레인에 비례하는 것을 이용하여 제작된 센서로 주로 대기압 이상의 고압 측정에 많이 사용되고 있다. 먼저 수정빔의 압력과 주파수간의 관계를 측정하고 또한 내장된 수정 온도센서의 공진 주파수를 측정하여 온도 보상을 위한 자료로 사용하였다. 규격에 나와 있는 수정빔의 기하학적 형상으로부터 거동에 관한 이론 모델식을 구하고 압력교정 자료로부터 얻어진 데이터를 이 식과 비교 분석하여 적합한 특성식과 인자를 구하였으며 게이지의 불확도를 추정하였다.모델은 길이가 유한한 0-차원 실린더 모델로 가정하였고, 이에 대한 기하학적 성질 및 열역학적 성질은 유효계수를 고려하여 산출하였다. 진공용기 이중 벽 내부로 흐르는 질소가스의 유량과 온도의 계산은 진공용기 내벽과 외벽을 각각 독립적인 열전달 요소로 가정하여 구성한 모델을 이용하였다. 전체 해석에서 각 열전달 요소의 비열 값은 온도에 따라 변화하는 비열의 특성을 반영하였으며. 진공용기와 플라즈마 대향 부품의 방사율(emissivity)은 앞서 가정했던 각 온도 상승 곡선에 대해서 각각 0.1, 0.2, 1.3의 경우를 가정하여 계산하였다. 직선적으로 증가하는 온도 상승 곡선중 2$0^{\circ}C$/hr의 온도상승율을 갖는 경우가 다른 베이킹 시나리오 모델에 비해 효과적이라 생각되며 초대 필요 공급열량은 200kW 정도로 산출되었다. 실질적인 수치를 얻기 위해 보다 고차원 모델로의 해석이 필요하리라 생각된다. 끝으로 장기적인 관점에서 KSTAR 장치의 베이킹 계획도 살펴본다.습파라미터와 더불어, 본 연구에서 새롭게 제시된 주기분할층의 파라미터들이 모형의 학습성과를 높이기 위해 함께 고려된다. 한편, 이러한 학습과정에서 추가적으로 고려해야 할 파라미터 갯수가 증가함에 따라서, 본 모델의 학습성과가 local minimum에 빠지는 문제점이 발생될 수 있다. 즉, 웨이블릿분석과 인공신경망모형을 모두 전역적으로 최적화시켜야 하는 문제가 발생한다. 본 연구에서는 이 문제를 해결하기 위해서, 최근 local minimum의 가능성을 최소화하여 전역적인 학습성과를 높여 주는 인공지능기법으로서 유전자알고리즘기법을 본 연구이 통합모델에 반영하였다. 이에 대한 실

• Journal of the Korean Dietetic Association
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• v.25 no.4
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• pp.269-280
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• 2019

The purpose of this study was to investigate the relationship between HMR use and eating habits in young Korean adults. This cross-sectional study was conducted on 575 adults (232 men, 343 women) in their 20s and 30s in Korea. Their use of HMRs (classified as ready-to-eat, ready-to-cook, and fresh convenience foods) and eating habits were surveyed. The main reasons for HMR use by men and women were convenience (54.7%, 64.4%) and promptness (24.2%, 24.2%), respectively. The most frequent place for HMR purchase was a convenience store (74.1% and 65.0%, respectively). Regarding the frequency of HMR use, 1~2 times a week was the highest for ready-to-eat (40.9%) and ready-to-cook (30.1%), while no eating was the highest for fresh convenience foods (41.0%). HMR preference was the highest (3.8 out of 5 on a 5-point scale) for ready-to-eat, followed by ready-to-cook (3.3 points) and fresh convenience foods (3.3 points). The use frequency and preference of total HMRs, ready-to-eat foods, and ready-to-eat foods were positively correlated with unfavorable eating habits, including unbalanced eating, overeating, salty eating, spicy eating, skipping, and irregular meals. However, fresh convenience foods showed negative correlations with unbalanced eating, overeating, and salty eating. The use frequency and preference of total HMRs, ready-to-eat foods, and ready-to-cook foods were positively correlated with undesirable eating habits. However, fresh convenience food showed a negative correlation with eating habits such as unbalanced, overeating, and salty eating. These results should be considered for favorable food production and consumer guidance to promote healthy food choices.

• Journal of Nutrition and Health
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• v.54 no.3
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• pp.262-276
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• 2021

Purpose: Although, the rate of skipping breakfast among adolescents has increased in recent years, there has been an increase in the consumption of home meal replacement (HMR). This study examines the recognition and preference of rice-based Korean style HMR for breakfast among adolescents in located at Jeollabuk-do. Methods: Total of 550 middle- and high-school students of Jeollabuk-do enrolled in this study signing a consent of participation. After conducting a preliminary survey, the questionnaire employed was modified according to the purpose of this study, and the self-recording method was appliedto fill out the questionnaire. Data were analyzed using IBM SPSS Statistics 25. The 𝛘²-test was performed for categorical variables, whereas continuous variables were analyzed by the independent t-test. Results: Results of this study determined that 272 students (54.6%) belonged tobreakfasteating group and 226 (45.4%) were in the breakfast-skipping group. The reasons specified by both groups for eating HMR were 'convenient to cook', 'delicious', and 'time-saving'. The a result of analyzing perception of the importance of HMR by classifying as whether to eat or not to eat breakfast, revealed that compared to the breakfast-skipping group, the breakfast-eating group considered 'hygiene and cleanliness' as important factors (p < 0.001). Considering the gender, school, and breakfast consumption, the most preferred Korean HMR were 'triangular gimbap', 'gimbap', and 'rice balls'. Conclusion: Results of this study indicate, when considering adolescents, there is a necessary for continuous researches to develop convenient breakfast substitutes that are easily consumed. Moreover, we believe that it is essential to impart proper cooking education and recipe distribution of the menu.

• Tunnel and Underground Space
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• v.32 no.5
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• pp.312-326
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• 2022

The generalized Hoek-Brown (GHB) criterion, which is recognized as one of the standard failure conditions for rock mass, is specialized for rock engineering applications and covers a wide range of rock mass conditions. Accordingly, many research efforts have been devoted to the incorporation of this criterion into the stability analysis of rock structures. In this study, the slip-line analysis method, which is a kind of elastoplastic analysis method, is combined with the GHB failure criterion to derive analytical equations that can easily calculate the plastic radius and stress distribution in the vicinity of the circular tunnel. In the process of derivation of related formulas, it is assumed that the behavior of rock mass after failure is perfectly plastic and the in-situ stress condition is hydrostatic. In the formulation, it is revealed that the plastic radius can be calculated analytically using the two respective tangential friction angles corresponding to the stress conditions at tunnel wall and elastic-plastic boundary. It is also shown that the plastic radius and stress distribution calculated using the derived analytical equations coincide with the results of Lee & Pietruszczak's numerical method published in 2008. In the latter part of this paper, the influence of the quality of the rock mass on the size of the plastic zone, the stress distribution, and the change of the tangential friction angle was investigated using the derived analytical equations.

• Geotechnical Engineering
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• v.7 no.4
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• pp.75-88
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• 1991

A lot of landslides has occurred in rainy seasons beginning at June through September in Korea, where about 70 percent of the total area is mountaneous. Piles can be used as one of the most useful methods to stabilize such landslides. When a row of piles is installed in soil undergoing lateral movement such as landslides, the soil across the open space between the piles can be retained by the arching action of the soil. For the purpose to establish a reasonable design method for stabilizing piles, a method for stability analysis of the slope containing stabilizing piles is presented, using the theoretical equation of the lateral force acting on the piles in soil undergoing lateral movement. In particular, the theoretical equation is arranged by applying the coefcients of lateral force as a simple equation. And also the differential equations proposed in the previous studies for the pile-stability analysis are modified, assumming that the piles above the sliding surface shall be subjected to the lateral reaction from soil in proportion to the pile deflection. Finally, to investigate the effect of stabilizing piles against landslides, an existing landslide slope in Korea is adopted as an example.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.41-61
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• 2023

The universal form of life in the era of the 4th industrial revolution can probably be summarized as the keyword "non-face-to-face". In particular, in terms of consumption activities, face-to-face contact is gradually changing to a system that minimizes, and offline stores are rapidly changing to non-contact services through kiosks and robots. The social structure is also changing with the passage of time, and most fundamentally, our dietary consumption patterns are changing. In particular, the increase in single-person households and the aging population are having a great impact on changes in the food service industry, which is closely related to dietary life. The HMR (Home Meal Replacement) market has grown significantly as the labor of cooking at home has decreased and the use of substitute foods has increased. As the size of the market has grown, the types of businesses that provide products have also diversified. The development of technology, non-face-to-face culture, and corporate management efficiency are intertwined, and unmanned stores are spreading recently. In this study, service quality attributes of HMR unmanned stores, where competition is gradually intensifying, are classified, and service quality classification using the Kano model and Timko's customer satisfaction coefficient are calculated to provide implications for service management based on customer satisfaction. As a result of the analysis, 'products with short cooking time' and 'variety of products (menu)' were classified as attractive qualities, and 'cleanliness inside/outside of the store' and 'products at reasonable prices' were classified as unified quality. In addition, 'convenience of self-checkout process' was classified as a natural quality, and 'convenience of in-store passage' was classified as an indifferent quality. Furthermore, when the service factor was satisfied within the HMR unmanned store, the factor with the highest satisfaction coefficient was 'product (menu) variety', and the factor with the highest dissatisfaction factor was 'convenience of self-checkout process'. Through the results of this study, it is intended to derive priorities in service quality management of HMR unmanned stores and provide strategic implications for related businesses.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.1
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• pp.1-12
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• 2005

An analytical procedure to analyze reinforced concrete (RC) beams subject to monotonic loadings is proposed on the basis of the moment-curvature relations of RC sections. Unlike previous analytical models which result the overestimation of stiffnesses and underestimation of structural deformations induced from ignoring the shear deformation and assuming perfect-bond condition between steel and concrete, the proposed relation considers the rigid-body-motion due to anchorage slip at the fixed end. The advantages of the proposed relation, compared with the previous numerical models, are on the promotion in effectiveness of analysis and reflection of influencing factors which must be considered in nonlinear analysis of RC beam by taking into account the nonlinear effects into the simplifying moment-curvature relation. Finally, correlation studies between analytical and experimental results are conducted to establish the applicability of the proposed model to the nonlinear analysis of RC structures.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.68-68
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• 2011

본 연구에서는 PV cell이 직달 일사에 노출되는 경우와 집광된 태양광에 조사되는 경우의 성능을 비교하는 한편 집광기의 형태에 따른 열적 성능을 검토하고자 하였다. PV cell은 본질적으로 반도체의 특성을 가지므로 작동온도의 상승에 따라 성능이 저하된다는 사실이 알려져 있으며, 태양조사의 강도 및 밀도 등 특성에 따라서도 성능의 변화를 예상할 수 있다. 그러나 이러한 성능변화에 관련된 인자들과 그 영향의 크기에 대한 정량적인 기술자료가 부족하므로 설치와 이용에 한계가 있는 것이 현실이다. 인공태양 장치(solar simulator)를 이용하여 0.7에서 1.2 sun 범위의 태양 조사 환경에서 결정질 실리콘계 PV cell과 집광형 PV cell의 성능을 검토하였다. 집광에 사용한 PTC는 집광면적의 폭이 500 mm이며, 집광 조사면적이 최소 10 mm인 경우 이론적 최대 집광비가 50이었다. PTC의 축방향으로는 균일한 태양조사가 있게된다는 것을 가정하여 모델의 길이는 간편한 실험을 위해 150에서 500 mm의 범위에서 제작하였다. 수평으로 놓인 PTC의 상부 초점 위치로부터 집광면이 아래 쪽에 위치할수록 집광 조사 면적이 증가하므로 PV cell의 크기에 따라 PTC 초점의 위치로부터 거리를 결정하였다. 한편, PTC 자체의 성능도 촛점거리와 집광면 폭의 비에 따라 달라질 수 있다는 가정 하에, 포물면의 최저 위치로부터 촛점거리는 각각 300, 400 및 500 mm가 되도록 세가지 형태를 제작하여 사용하였다. 동일한 형태의 PTC에서 PV cell의 동일한 설치 위치에서도 최고 $110^{\circ}C$ 범위의 PV cell의 작동 (표면) 온도에 따른 성능의 차이를 관찰하기 위해 셀의 후면을 냉각시키는 경우와 그렇지 않은 경우를 비교하였다. PV cell의 표면 온도 측정을 위해서, 후면의 온도와 같이 광선 차단 효과의 우려가 없는 경우에는 열전대를 설치하였으며, 셀의 전면 온도 측정을 위해서는 비접촉식 적외선 온도계를 사용하였다. 냉각 방법으로는 공기를 이용한 자연대류와 액체를 사용하는 강제대류의 경우를 고려하였으며, 필요에 따라 적절히 설계된 히트싱크를 설치하여 비교 실험을 진행하였다. 강제대류 냉각의 경우는 항온조를 사용하여 순환하는 냉각수의 유량과 공급온도를 변화시킴으로써 PV cell의 작동온도를 조절하고, 이에 따른 발전 성능의 변화를 관찰하였다. 본 연구에서 도출한 실험 및 분석 결과는 PV cell의 설치 환경과 작동온도의 변화에 따라 그 성능 변화를 예측할 수 있는 기술적 자료를 제공함으로써 에너지 이용의 합리화를 도모하는데 기여할 수 있을 것이다.