• 한국안전학회지
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• 제37권2호
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• pp.28-34
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• 2022

This study analyzes the impact that accidents and near misses have on clients' and contractors' awareness of safety culture. Due to the unique characteristic of employment structure in Korea, the occurrence of accidents differs by company size, which has relevant implications for the establishment of safety culture. Attention has been drawn to the importance of the management of accidents and near misses, with safety awareness acting as a core factor. A positive effect on the prevention of accidents could be achieved by noting the difference in safety awareness between clients and contractors and suggesting an associated suitable safety management system. In support of this study, a survey was distributed to workers in the automobile manufacturing industry (May-August 2020), and data from a total of 574 workers was collected and analyzed, including 399 clients' worksers and 175 contractors' workers. The questionnaire addressed participants' experiences of accidents and near misses as well as 50 items from the Nordic Occupational Safety Climate Questionnaire. Analysis of the responses was conducted using the methods of frequency analysis, Fisher's exact test, t-test, correlation analysis, and regression analysis. The results demonstrated that clients had more experiences with accidents and near misses compared to contractors. Additional differences between clients and contractors were noted in terms of the safety culture factors of learning, communication, and trust. A correlation was observed between the experience of accidents and safety justice management: for clients and contractors who experienced accidents, safety justice management was 9.4 times higher. Furthermore, clients' and contractors' awareness of employees' commitment to safety was determined to be 28.5 times higher in those who had experienced near misses This study concludes that, in order to improve accident prevention through the management of accidents and near misses, clients must focus on overseeing safety justice management and aspects of safety culture factors, while contractors must focus efforts on managing employees' commitment to safety. In further applications, this study could provide baseline data for health and safety activities in terms of the safety culture of clients and contractors. Further study on the establishment of safety culture as related to employment structure is proposed for future research.

• 해양환경안전학회지
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• 제28권2호
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• pp.307-313
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• 2022

지구 온난화와 기후변화에 대응하기 위해 국제적으로 재생 에너지의 개발이 확대됨에 따라 풍력발전의 비중도 점차 늘어가고 있다. 태양광발전에 비해 24시간 생산이 가능하지만 대형 풍력발전기를 대규모로 설치하기 때문에 주변의 레이더나 통신 장비들의 동작에 간섭을 일으키는 지에 대한 분석이 필요하다. 본 연구에서는 해상풍력 발전단지 외해를 항해하는 선박이 VHF 대역으로 조난 통신을 송신할 경우, 육지의 기지국에서 신호를 수신할 수 있는지를 분석하였다. 대상지역 주변의 수치지형도, 풍력발전기 캐드 모델, 풍력발전단지 배치도를 바탕으로 주변 해역 및 발전단지를 수치해석이 가능하도록 모델링하였다. 광범위한 지역에 대한 전파 분석에 적절한 고주파 해석기법 중 PO, SBR 기법을 적용한 전용 프로그램으로 전자파 간섭 여부를 분석하였다. 해상풍력 발전단지 외곽에서 송신한 VHF 대역 전자파에 대해 육상 기지국에서는 약간의 수신전력 저하는 있지만 기준치 이상의 전력을 수신하였다. 선박과 육상 기지국 사이의 가시선을 완전히 가리는 경우에 수신 전력의 저하가 발생하였으나, VHF대역이 파장이 길어 회절이나 반사 등의 효과로 육상 기지국까지 충분한 전파가 도달하는 것으로 판단된다.

• 운동영양학회지
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• 제24권2호
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• pp.30-37
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• 2020

[Purpose] The present study investigated the effect of endurance exercise with blood flow restriction (BFR) performed at either 25% maximal oxygen uptake (${\dot{V}}O_2$ max) or 40% ${\dot{V}}O_2$ max) on muscle oxygenation, energy metabolism, and endocrine responses. [Methods] Ten males were recruited in the present study. The subjects performed three trials: (1) endurance exercise at 40% ${\dot{V}}O_2$ max without BFR (NBFR40), (2) endurance exercise at 25% ${\dot{V}}O_2$ max with BFR (BFR25), and (3) endurance exercise at 40% ${\dot{V}}O_2$ max with BFR (BFR40). The exercises were performed for 15 min during which the pedaling frequency was set at 70 rpm. In BFR25 and BFR40, 2 min of pressure phase (equivalent to 160 mmHg) followed by 1 min of release phase were repeated five times (5 × 3 min) throughout 15 minutes of exercise. During exercise, muscle oxygenation and concentration of respiratory gases were measured. The blood samples were collected before exercise, immediately after 15 min of exercise, and at 15, 30, and 60 minutes after completion of exercise. [Results] Deoxygenated hemoglobin (deoxy-Hb) level during exercise was significantly higher with BFR25 and BFR40 than that with NBFR40. BFR40 showed significantly higher total-hemoglobin (total-Hb) than NBFR40 during 2 min of pressure phase. Moreover, exercise-induced lactate elevation and pH reduction were significantly augmented in BFR40, with concomitant increase in serum cortisol concentration after exercise. Carbohydrate (CHO) oxidation was significantly higher with BFR40 than that with NBFR40 and BFR25, whereas fat oxidation was lower with BFR40. [Conclusion] Deoxy-Hb and total Hb levels were significantly increased during 15 min of pedaling exercise in BFR25 and BFR40, indicating augmented local hypoxia and blood volume (blood perfusion) in the muscle. Moreover, low-and moderate-intensity exercise with BFR facilitated CHO oxidation.

• 인간식물환경학회지
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• 제24권2호
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• pp.169-178
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• 2021

Background and objective: Education based on agricultural experience in school gardens is coming to the fore as a solution to reduce the negative effect of rapid urbanization and the development of information technology (IT) on students. Accordingly, this study aimed to investigate how parents of elementary, middle, and high school students in Korea perceive the value of education service using school gardens, as well as their willingness to participate in and pay for such service, and to utilize the results in a quantitative assessment of the socioeconomic value of the education service. Methods: A contactless online survey on the perceived value of education service using school gardens was conducted on 1,010 parents of elementary, middle, and high school students in Korea's five major districts from October 22 to 26 (5 days) of 2020 by M, a Korean specialized survey agency. The data collected was analyzed using SPSS for Windows 25.0 and Excel to obtain the frequency and ratio of each measured item. Results: The respondents had an average of 1.83, of which 52.8% were male. 55.3% of the respondents were aware of the education service using school gardens, and 27.9% experienced the service. When asked if they saw the educational service using school gardens as necessary, 79% answered in the affirmative. In terms of the difference in perception of the need for the service according to experience, 91.8% of the parents who experienced the service responded that it was necessary, indicating that it is important to provide opportunities to experience this service to expand the scope of service. 54.9% of all respondents responded they were willing to pay the costs required for school gardens. When income tax was used as a payment method, the average amount parents were willing to pay was 13,193 KRW, and the tax rate was 2.02%. Based on experience, those who experienced this service had a higher need and willingness to pay for the service than those who had not experience, but the actual amount or tax rate was low as they knew how it was operated. Conclusion: As basic research on the assessment of the value of agricultural experience education using school gardens, this study determined how parents perceive this form of education service as well as their willingness to participate and pay for the service. These findings can be used to systemize the assessment indicators and promote the value of the education service using school gardens, allowing students to maintain a healthy and happy school life through agricultural experience.

• 대한한의학회지
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• 제43권2호
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• pp.61-74
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• 2022

Objectives: This study aimed to explore the short-term effects of bilateral masticatory training using an intraoral device on memory and concentration, which is an advanced form of Gochi, compared to the unilateral form with gum. Methods: Thirty young healthy participants (age, 16-30 years) were screened and randomly assigned to one of two sequences in a crossover design. The participants assigned to sequence A (n=15) performed bilateral mastication using an intraoral device with a total of 300 taps, followed by unilateral mastication using gum with the same number of repetitions and frequency, separated by a 7-day washout period. A reverse order was used for sequence B. The primary and secondary outcomes were the digit span test result and the symbol digit modality test and the word list recall results, respectively, which were conducted before and after each intervention. Results: Symbol digit modality test scores increased by 12.03±8.33 with bilateral mastication, which was significantly higher than that obtained with chewing gum (5.17 points;95% confidence interval: 0.99, 9.34; p<0.05). Changes in the digit span test and word list recall scores were not significantly different between the two groups. In the digit span test forward, symbol digit modality test, and word list recall test, bilateral mastication was not inferior to unilateral mastication in improving memory and concentration. Conclusions: Bilateral masticatory exercises using an intraoral device are not inferior to unilateral mastication with gum for improving memory in healthy young individuals. Further research is needed to determine the efficacy of bilateral masticatory training on cognitive function.

• 지구물리와물리탐사
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• 제24권4호
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• pp.180-193
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• 2021

복소 전기비저항 탐사기법은 진동수 영역에서 전기비저항과 위상을 측정하여 지하 매질의 다양한 특성정보를 획득할 수 있는 탐사기법으로 최근 그 활용성이 증가하고 있다. 이 논문에서는 복소 전기비저항 탐사기법의 활용성을 높이기 위하여 획득한 자료에 대한 3차원 역산 알고리듬을 개발하였다. 이를 위한 모델링에는 전자기 커플링 효과를 무시하는 경우에 적용할 수 있는 포아송 방정식을 적용하였으며, 역산에는 기존의 평활화된 역산법을 복소수로 확장하는 방법으로 알고리듬을 개발하였다. 역산의 안정성 및 현장자료의 적용성을 높이기 위하여 라그랑지 곱수를 역산 과정에서 오차 벡터와 모델 증분 벡터의 크기에 따라 자동적으로 조정되도록 하는 기법을 도입하였다. 또한, 잡음이 많이 포함된 위상자료로 인한 자료의 손실을 보완하기 위하여 역산반복 단계에서 초반부는 전기비저항 자료만을, 후반부는 전기비저항 자료와 위상 자료를 모두 역산하는 두 단계로 구성된 역산기법을 제시하였다. 수치 모형실험에 대한 역산 시험결과 안정적인 역산 결과를 얻을 수 있었으며, 개발된 3차원 역산 알고리듬을 국내 천열수 광산 인근에서 수행한 복소 전기비저항 탐사자료 해석에 적용하여 그 타당성을 확인하였다.

• 한국지반환경공학회 논문집
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• 제22권12호
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• pp.33-40
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• 2021

도심지에서 빈번하게 발생하는 지반함몰 사고는 지하시설물의 노후화, 지하개발 활동에 따른 지반의 교란과 지하수 변화 등 다양한 원인에 의해 발생하고 있다. 지반함몰 위험을 사전 예측하기 위해서는 지반함몰 사고에 영향을 미치는 인자들에 대한 지반 공학적 및 수리학적 검토가 필요하다. 따라서 본 연구에서는 현재 운영되고 있는 지반조사 데이터 및 지하수위 변동 정보를 이용하여 지반함몰이 발생한 연구대상 지역의 3차원 지반모델링 및 월별 지하수위에 대한 자료 분석을 수행하였으며, 이를 활용해 실제 지반함몰 발생 이력과 지반조건 및 지하수위 변화와의 관계성을 확인하였다. 또한, 기존 시추정보에서 통일 분류 체계(USCS)에 따라 제시된 흙의 공학적 특성을 지반함몰과 연관된 공학적 지표인 흙의 내부 침식 민감도로 재구성하여 지반함몰 위험도를 가시화하는데 활용하는 방법론을 제시하였다. 연구결과, 지반함몰 발생 지역의 지반은 내부 침식이 취약한 모래(SM, SC, SP, SW)가 40% 이상 구성되어 있음을 확인했으며, 지하수위 변화에 따른 지반함몰 발생빈도와의 관계성도 확인할 수 있었다.

• 품질경영학회지
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• 제50권2호
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• pp.287-304
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• 2022

Purpose: The size of the salad consumption market has expanded since Covid-19, and continuous growth is predicted. Therefore, by extracting influential core purchasers in the salad consumption market and analyzing their purchasing behaviors and consumer types, this study intended to provide basic data for establishing a marketing strategy. Methods: The analysis data is the purchasing data of 576 people who have purchased salads between 2016 and 2020 (panel data of the Rural Development Administration), and in the social network analysis, the centrality structure was analyzed. Results: First, in the results of analyzing the causes of the rapid increase in salad consumption in 2020, it was found that the increase in consumption of new purchasers (n=102) had little effect. The existing consumer type (n = 474), which has been the majority of the salad consumption market so far, were consumers with stable income. However, the results of study indicated that the type of consumers has expanded since low-income class as well as high-income class increased consumption of purchasing salad. Second, in the results of analyzing the types of key purchasers with great influence in the salad consumption market, there was a difference from the results of frequency analysis in age, number of family members, existence/absence of children, and income decile. This suggests that there should be a difference between the type of customers according to the apparent quantitative figure and the actual influential purchasers. Third, in the results of analyzing the salad purchasing behaviors of core purchasers, the purchasing site for existing purchasers was large-scale marts and for new purchasers it was corporate-type supermarkets. Purchases were concentrated on Saturdays for both existing and new purchasers. As for the purchased products, existing purchasers had a high preference for products made of chicken, and new purchasers had a high preference for vegetable/fruit salad. In particular, in the results of purchased products by age group, in the case of 50s and 60s, it was an interesting result that there was a difference between the products purchased by the existing and new purchasers even though they were the same age. Conclusion: When establishing a marketing strategy in the salad consumption market, it is necessary to pay attention to the purchasing behavior of key buyers.

• 사물인터넷융복합논문지
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• 제8권4호
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• pp.85-96
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• 2022

본 연구 목적은 디지털 경제 시대에 요구되는 경영전략과 조직문화가 경영성과에 어떠한 영향이 있는지를 규명하였다. 디지털 선도국가로 접근하는데 필요한 경영전략과 조직문화에 대한 기초 자료를 제공하였다. 자료수집은 2022년 3월 1일부터 5월 30일까지 J도에 소재하며 디지털 경제에 관련된 산업을 하고 있는 기업을 대상으로 설문조사를 실시하였다. 설문조사는 온라인 비대면 조사를 진행하였고, 총 225개의 기업이 조사에 참여하였다. 통계분석은 빈도분석, 탐색적 요인분석 및 신뢰도 분석, 군집분석, 독립표본 t-test, 다중회귀분석을 실시하였다. 연구결과는 다음과 같다. 첫째, 조직문화는 혁신지향, 관계지향, 과업지향, 위계지향에서 선호도에 따라 높은 집단과 낮은 집단으로 분류되었다. 둘째, 조직문화 4가지 유형은 선호도에 따라 공격형 전략, 분석형 전략, 방어형 전략, 차별화 전략, 원가우위 전략, 재무성과, 비재무성과에서 차이가 나타났다. 셋째, 재무성과에 미치는 경영전략은 분석형 전략, 차별화 전략, 공격형 전략, 원가우위 전략으로 나타났다. 넷째, 비재무성과에 미치는 경영전략은 차별화 전략, 방어형 전략, 분석형 전략, 공격형 전략, 원가우위 전략, 집중화 전략으로 나타났다. 다섯째, 재무성과에 미치는 조직문화는 과업지향으로 나타났다. 여섯째, 비재무성과에 미치는 조직문화는 혁신지향, 관계지향으로 나타났다. 이러한 연구를 통하여 국내 시장에서는 경기가 활성화 되고, 글로벌 시장에서는 새롭게 도약할 수 있는 성장 생태계가 조성되길 기대한다.

• 한국지반환경공학회 논문집
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• 제24권2호
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• pp.31-40
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• 2023

본 연구는 고밀도 지진 관측망 구축 시 지표 가속도 측정 및 조기경보 활용을 위한 효율적 관측소 설치 방법을 수립하기 위하여 테스트베드에 지표, 1m, 2m, 9m 깊이의 임시관측소를 설치하여 상시 잡음, 인공 가진 신호 및 지진 계측 자료의 깊이별 변화를 분석하였다. 연구대상지의 상시 잡음 분석 결과 1s 이하의 단주기 영역은 주변의 인위적 잡음이 우세하였으며, 1s 이상 장주기 영역은 풍속의 변동과 큰 상관성을 보였다. 2차원 지진계 배열을 통한 상시 잡음 진동수-파수(FK) 분석 결과 단주기 상시 잡음은 표면파 보다는 주로 체적파의 형태로 유입되는 것으로 추정된다. 잡음 수준 분석 결과 9m 이하에서는 낮은 수준의 상시 잡음이 관측되었으나, 지표, 1m, 2m 지진계에서는 토사층의 동적 거동에 의해 T < 0.1s에서 잡음의 증폭이 발생하는 것을 확인하였다. 인공 가진실험 및 괴산지진 계측 자료 분석 결과 전반적으로 깊이가 깊어질수록 신호의 크기가 감소함을 확인하였으며, 스펙트럼비 및 응답스펙트럼 분석 결과 지표와 1m에서 3m 깊이 토사층의 고유진동수에 해당하는 20Hz(T=0.05s) 대역의 지반운동이 크게 증폭되는 것으로 나타났다. 본 연구 결과 상시미동과 가진실험을 통해 대상구간의 관측환경을 조사하여 지진계 설치 방법 및 깊이 선정시 활용할 수 있는 것으로 나타났으며, 향후 다수의 지역에서 다양한 환경을 고려한 연구가 진행된다면 관측소 설치 깊이, 설치방법, 환경 조사방법에 대한 가이드라인을 제시하는데 큰 도움이 될 것으로 기대된다.