• 한국지리정보학회지
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• 제23권4호
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• pp.120-139
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• 2020

본 연구에서는 CLUE-s(Conversion of Land Use and its Effects at Small regional extent)와 RCP(Representative Concentration Pathway) 4.5 및 8.5 HadGEM3-RA(Hadley Centre Global Environmental Model version 3 Regional Atmosphere)시나리오를 사용하여 미래 농지이용 변화와 기후변화가 관개 필요수량에 미치는 영향을 평가하였다. 논산시(55,517.9ha)의 농지이용 항목으로 논, 밭, 시설재배지를 고려하고 DIROM (Daily Irrigation Reservoir Operation Model)을 이용해 탑정저수지 수혜구역(5,713.3ha)에 대한 관개 필요수량(Irrigation Water Requirement, IWR)을 추정하였다. CLUE-s를 이용한 미래 농지이용 변화를 모의하기 위해 환경부의 2007년, 2013년, 2019년의 토지피복도 6개 항목(수역, 시가지, 논, 밭, 산림, 시설재배지)을 적용하였다. 그 결과, 2100년은 2013년에 비해 논과 밭이 5.0%, 7.6% 감소했으며, 시설재배지는 24.7% 증가하는 것으로 전망되었다. 미래의 농지이용과 기후변화를 모두 고려한 경우의 RCP 4.5 및 RCP 8.5 모두 2090s(2090~2099) IWR은 미래 기후변화만 고려한 경우에 비해 논과 밭에서는 각각 2.1%, 1.0% 감소하고 시설재배지에서는 11.4% 증가하는 것으로 전망되었다.

• 생약학회지
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• 제53권3호
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• pp.162-169
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• 2022

This study investigated the mycotoxins (aflatoxin B₁, B₂, G₁, G₂, fumonisin B₁, B₂, ochratoxin A and zearalenone) contained in edible and medicinal plants in Seoul Yangnyeong market during 2020-2021. We analyzed contamination of mycotoxins using LC-MS/MS and evaluated risk assessment. The method was validated by assessing matrix effects, linearity, limit of detection (LOD), limit of quantification(LOQ) and recovery. Matrix-matched standard calibration was used for calibration curves showed good linearity (r²>0.999). The LOD, LOQ and recovery were 0.01-0.23 ㎍/kg, 0.04-0.71 ㎍/kg and 75.5-117.9% respectively. Mycotoxins were detected in 22 of 171 samples; aflatoxin B₁ (6.66 ㎍/kg), fumonisin (7.54-64.68 ㎍/kg), ochratoxin A (4.21-10.56 ㎍/kg) and zearalenone (7.31-60.76 ㎍/kg). In the risk assessment, the MOE (Margine of Exposure) of aflatoxin B₁ and ochratoxin A were in the range of 1.48×10³-2.36×10⁵. No items exceeded 100% in %TDI (Tolerable Daily Intake) of fumonisin (B₁+B₂) and zearalenone.

• 한국농공학회논문집
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• 제64권6호
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• pp.65-75
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• 2022

Livestock industry in Korea has been growing rapidly and has reached 23 trillion Korean won in 2021. This study focuses on broiler, which is one of the largest sectors in livestock industry. As the effects of climate change get more serious, primary industry such as livestock industry is fragile to climate change since it directly interacts with nature. Therefore, maintaining suitable rearing environment is important. One of the most frequently used ventilation type for controlling the rearing environment of broiler house, tunnel ventilation, causes frequent air velocity fluctuation which makes maintaining the rearing environment important. By measuring the air temperature, relative humidity and air velocity in various points inside the broiler house, the internal thermal environment uniformity was analyzed according to length, width and zone. The experimental house was found to have dead zone with high air temperature, relative humidity and low air velocity near the end of the inlet and at the end of the broiler house. By using heat stress index to analyze quantitatively, zone with highest heat stress index was found to increase by 7.55% compared to the lowest zone. As a result, to maintain uniform rearing environment inside the broiler house, different factors must be measured and analyzed and used to operate the environmental control facilities.

• 한국농공학회논문집
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• 제64권6호
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• pp.87-99
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• 2022

The meat consumption per person has continuously increased in recent years. However, the labor force in the domestic livestock industry has decreased due to the declining and ageing population. In order to increase productivity, the government have developed and distributed design standard of livestock houses. Presently, report showed that the adaptation rate of the developed livestock house design standard on the real farm was still low. Thus, this paper aimed to find ways to improve the utilization of the design standard through surveys. The survey was conducted on 650 farms across the country. Analysis of the result showed that in the poultry house, the unawareness of farmers to the design standard was found to be the biggest reason for not using the design standards. On the other hand, in the swine house, the previously built swine houses do not fit with the design standard. From these result, the following recommendations were suggested: 1) promotion and education are needed to enhance usage of design standard; 2) since it is impossible to make a design standard considering all the farm sites, it is important to consider the conditions of various farm site prior to enhancement of the design standard; 3) improvement factors such as reinforcing the ventilation design, reflecting animal welfare, preventing livestock diseases, and enhancing ICT devices can also be promoted.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1610-1610
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• 2001

Microbiological examination of silage is of little value in gauging the outcome of silage, and so chemical analysis is more reliable and meaningful indicator of quality. On the other hand chemical assessments of the principal fermentation products provide an unequivocal basis on which to judge quality. Livestock require energy, protein, minerals and vitamins from their food. While fresh forages provide these essential items, conserved forages on the other hand may be deficient in one or more of them. The aim of the conservation process is to preserve as many of the original nutrients as possible, particularly energy and protein components (Woolford, 1984). Silage fermentation is important to preservation of forage with respect of feeding value and animal performance. Chemical and bacteriological changes in the silo during the fermentation process can affect adversely nutrient yield and quality (Moe and Carr, 1984). Many of the important chemical components of silage must be assayed in fresh or by extraction of the fresh material, since drying either by heat or lyophilisation, volatilises components such as acids or nitrogenous components, or effects conversion to other compounds (Abrams et al., 1987). Maize silage dorms the basis of winter rations for the vast majority of dairy and beef cattle production in Uruguay. Since nutrient intake, particularly energy, from forages is influenced by both voluntary dry matter intake and digestibility; there is a need for a rapid technique for predicting these parameters in farm advisory systems. Near Infrared Reflectance Spectroscopy (NIRS) is increasingly used as a rapid, accurate method of evaluating chemical constituents in cereals and dried forages. For many years NIRS was applied to assess chemical composition in dry materials (Norris et al., 1976, Flinn et al., 1992; Murray, 1993, De Boever et al., 1996, De la Roza et al., 1998). The objectives of this study were (1) to determine the potential of NIRS to assess the chemical composition of dried maize samples and (2) to attempt calibrations on undried samples either for farm advisory systems or for animal nutrition research purposes in Uruguay. NIRS were used to assess the chemical composition of whole - plant maize silage samples (Zea mays, L). A representative population of samples (n = 350) covering a wide distribution in chemical characteristics were used. Samples were scanned at 2 nm intervals over the wavelength range 400-2500 nm in a NIRS 6500 (NIRSystems, Silver Spring, MD, USA) in reflectance mode. Cross validation was used to avoid overfitting of the equations. The optimum calibrations were selected on the basis of minimizing the standard error of cross validation (SECV). The calibration statistics were R$^2$ 0. 86 (SECV: 11.4), 0.90 (SECV: 5.7), 0.90 (SECV: 16.9) for dry matter (DM), crude protein (CP), acid detergent fiber (ADF) in g kg$\^$-1/ on dry matter, respectively for maize silage samples. This work demonstrates the potential of NIRS to analyse whole - maize silage in a wide range of chemical characteristics for both advisory farm and nutritive evaluation.

• Journal of Periodontal and Implant Science
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• 제54권2호
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• pp.75-84
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• 2024

Purpose: This study investigated the relationship between the number of days that hospital visits were postponed and changes in clinical parameters due to the spread of coronavirus disease 2019 (COVID-19), after the Japanese government declared a state of emergency in April 2020. Methods: Regarding the status of postponement of appointments, we analyzed the patients who had visited the Nihon University Hospital at Matsudo for more than 1 year for supportive periodontal therapy (SPT) and classified them into low-, moderate- and high-risk subgroups according to the periodontal risk assessment (PRA). Clinical parameters for periodontal disease such as probing depth (PD), full-mouth bleeding score (FMBS), full-mouth plaque score, periodontal inflamed surface area (PISA), and periodontal epithelial surface area (PESA) were analyzed in 2 periods, from October 2019 to March 2020 and after April 2020. Correlation coefficients between days of deferral and the degree of changes in clinical parameters were calculated. Results: The mean age of the 749 patients was 67.56±10.85 years, and 63.82% were female. Out of 749 patients, 33.24% deferred their SPT appointments after April 2020. The average total of postponement days was 109.49±88.84. The number of postponement days was positively correlated with changes in average PD (rs=0.474) and PESA (rs=0.443) in the high-risk subgroup of FMBS, and average PD (rs=0.293) and PESA (rs=0.253) in the highrisk subgroup of tooth number (TN). Patients belonging to the high-risk subgroups for both FMBS and TN had a positive correlation between postponement days and PISA (rs=0.56). Conclusions: The findings, the spread of COVID-19 appears to have extended the visit interval for some SPT patients. Moreover, longer visit intervals were correlated with the worsening of some clinical parameters for SPT patients with high PRA.

• Imaging Science in Dentistry
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• 제54권1호
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• pp.81-91
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• 2024

Purpose: The objective of this study was to propose a deep-learning model for the detection of the mandibular canal on dental panoramic radiographs. Materials and Methods: A total of 2,100 panoramic radiographs (PANs) were collected from 3 different machines: RAYSCAN Alpha (n=700, PAN A), OP-100 (n=700, PAN B), and CS8100 (n=700, PAN C). Initially, an oral and maxillofacial radiologist coarsely annotated the mandibular canals. For deep learning analysis, convolutional neural networks (CNNs) utilizing U-Net architecture were employed for automated canal segmentation. Seven independent networks were trained using training sets representing all possible combinations of the 3 groups. These networks were then assessed using a hold-out test dataset. Results: Among the 7 networks evaluated, the network trained with all 3 available groups achieved an average precision of 90.6%, a recall of 87.4%, and a Dice similarity coefficient (DSC) of 88.9%. The 3 networks trained using each of the 3 possible 2-group combinations also demonstrated reliable performance for mandibular canal segmentation, as follows: 1) PAN A and B exhibited a mean DSC of 87.9%, 2) PAN A and C displayed a mean DSC of 87.8%, and 3) PAN B and C demonstrated a mean DSC of 88.4%. Conclusion: This multi-device study indicated that the examined CNN-based deep learning approach can achieve excellent canal segmentation performance, with a DSC exceeding 88%. Furthermore, the study highlighted the importance of considering the characteristics of panoramic radiographs when developing a robust deep-learning network, rather than depending solely on the size of the dataset.

• 생태와환경
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• 제44권3호
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• pp.272-279
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• 2011

본 연구는 OECD 조사 연구 사업의 일환으로 2007년 3,905톤이 생산된 시안화구리의 환경영향에 대해서 물리 화학적 특성, 국내 외 사용량, 환경노출, 환경거동 및 수생태 독성 자료를 이용해 초기위해성평가를 위한 자료를 수집하였다. 물리 화학적 특성에서는 크림색의 결정형 물질로 녹는점이 매우 높은 일반적인 무기화합물의 특성을 보였으나, 시안화칼슘 등과 같은 11개 시안화합물에 비해 매우 낮은 수용해도를 나타내었다(WHO, 2004). 환경 중 노출 개연성은 생산 및 제조 공정이 주요 원인으로 파악되었다. 구리의 전기도금 용도로 사용되는 본 물질은 밀폐된 환경에서 생산되어 외부로의 유출을 억제하고 있으나, 생산 공정 및 도금과정에서 발생되는 산업 폐수 등의 방류 통해 환경으로 유출될 가능성이 있다. 이러한 경로로 유출된 시안화구리의 환경거동성에 대한 연구 자료는 존재하지 않았으며, 무기물의 염에 해당되는 물질로 환경거동 예측 모델링도 불가능하였다. 그러나 하수처리장 배출수의 구리 측정결과(MOE, 2008d)가 낮은 점 등을 들어서 노출평가에 대한 부분은 우선 고려 대상에서 제외하였다. 그러나 낮은 농도로 노출된 시안화구리는 물, 토양, 퇴적물 및 생물체로 이동될 가능성이 존재하여 본 연구에서는 물 환경에 대한 시안화구리의 독성학적 영향을 영양단계에 근거한 3개 실험종 (조류, 물벼룩 및 어류)으로 평가하였다. 평가 결과 모든 실험종의 50% 영향 치사농도 (E(L)$C_{50}$), 최소영향관찰농도 (LOEC) 및 무영향관찰농도 (NOEC)가 1.0 mg $L^{-1}$ 이하로 나타났고, 이를 GHS 분류체계와 대조한 결과 Hazard category 1에 해당하는 고독성 물질로 평가되었다. 위와 같이 조사된 자료를 근거로 하여 시안화구리에 대한 초기 생태위해성 평가를 수행하였다. 대상물질은 사용량이 높으나 작업장내에서는 노출 개연성이 낮고, 무기물의 염인 점을 감안하여 환경거동성은 높지 않을 것으로 판단하였다. 이러한 점을 감안할 때, 본 물질은 생산량 및 사용량이 높은 국가는 노출로 야기되는 수생태 독성을 중점적으로 평가해야 할 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
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• 제17권2호
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• pp.34-64
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• 1989

포장(包裝) 용적(容積) 감소에 따른 수송비(輸送費) 절감(節減) 효과(效果)가 있어 조립시(組立式) 탁자류(卓子類) 가구(家具)의 제작(製作)에 널리 쓰이는 CBA(corner block with anchor bolt) 접합방식(接合方式)은 일정기간(一定期間) 사용(使用)함에 따라 접합부위(接合部位)가 약해지고 그 결과(結果) 구조(構造)가 불안정(不安定)하게 되는 반강접합(半剛接合)(semi-rigid joint) 특유(特有)의 결점(缺點)도 지니고 있다. 따라서 본(本) 연구(硏究)에서는 CBA 접합(接合) 강도(强度)에 영향하는 주요(主要) 설계(設計) 인자(因子)로서 side rail 규격, corner block의 side rail에의 부착시(時) 보강재(補强材)의 효과(效果) 및 corner block관통 anchor bolt의 사용(使用) 수(數) 그리고 corner block의 형태등(等)의 평가(評價)를 하기 위해 22개(個)의 접합군(接合群) 별(別)로 총(總) 88개(個)의 table section 시험체(試驗體)를 제작(製作)한 후(後)그들의 강성(剛性) 계수(係數)(Z - 값) 및 유효강도(有效强度)를 수평 하중(荷重)에 의한 변형측정(變形測定) 실험(實驗)을 통해 결정(決定)한 후 설계(設計) 인자별(因子別) 효과(效果)를 비교 분석(分析)하였다. 분석결과(分析結果), side rail의 높이 증대(增大) 및 corner block 부착시(時) PVAc 수지(樹脂)의 사용효과(使用效果)가 뚜렷하여 유효강도(有效强度)의 유의적(有意的) 향상(向上)을 나타냈고 anchor bolt의 효과(效果) 역시 2개 사용시(使用時)가 1개 사용시(使用時) 보다 훨씬 큰 것으로 나타났다. 또 side rail 높이 와 anchor bolt 사용(使用) 수(數)간에는 상호작용(相互作用) 효과(效果)도 있었다. 그러나 side rail의 두께 효과(效果)는 22mm에서 25mm로 증대(增大)시켰을때 뚜렷한 상승 경향(傾向)은 보여주지 못했다. 한편 corner block의 형태는 MDF를 주재료(主材料)로 사용(使用)한 탁자(卓子) 설계시(設計時)는 두께 25mm, 높이 100mm의 side rail에 PVAc 수지(樹脂)로 보강(補强)하고 mitered corner block에 2개(個)의 anchor bolt를 관통시킨 경우가 유효강도(有效强度) 3171.7 kgf-cm로 22개의 접태군(接台群)들 중 최대치(最大値)를 나타냄으로써 miter type이 rectangular type보다 바람직한 것으로 나타났다. 결론적(結論的)으로 자재(資材)의 효과적(效果的) 이용(利用)을 통한 생산비(生産費) 절감(節減)과 동시(同時)에 구조(構造)의 안정(安定)된 강도적(强度的) 측면(側面)을 고려할 때, 두께 22mm, 높이 75mm의 MDF side rail에 mitered corner block을 PVAc 수지(樹脂)와 나사못을 이용하여 부착한 후(後) 2개(個)의 anchor bolt를 관통시키는 방법(方法)을 가장 합리적(合理的)인 MDF 사용(使用) 조립시(組立式) 탁자(卓子) 설계(設計) 방안(方案)으로 제시(提示)하는 바이다.

• 한국환경농학회지
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• 제24권2호
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• pp.77-82
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• 2005

괴산지역 내 소규모 농업유역을 대상으로 영농기 농촌 소유역에서 발생하는 비점오염 물질의 유출 특성을 조사하고자 소하천의 본류, 생활하수 유입하천 및 강수의 오염물질 농도와 하천 유량을 측정하여 오염부하를 계산하였다. 그 결과 영농기 동안 농촌유역 소하천 말단에서의 수질은 BOD의 경우 강우기 평균 3.0 mg/L, 평상시 평균 2.4 mg/L의 값을 보였으며, SS의 경우 강우기 평균 76.6 mg/L, 평상시 평균 10.9 mg/L을 나타냈으며, T-N과 T-P는 각각 강우기 평균 8.7, 0.16 mg/L, 평상시 3.5, 0.11 mg/L의 값을 나타내었다. 연구 기간 동안 측정한 수질 농도와 유량을 곱하여 부하로 계산한 결과 영농기에 유출되는 오염부하의 경우 95% 이상이 강우기에 유출되는 것으로 나타났으며, 연구기간 동안 유역 말단에서 측정된 오염물질의 부하량은 T-N의 경우 $26.63kg/km^2/day$, T-P의 경우 $0.62kg/km^2/day$의 값을 나타내어 기존 연구 결과의 범위 안에 있었다. 대상유역의 발생 및 배출 오염부하를 산정하기 위하여 환경부의 오염총량관리계획수립지침에 의거 계산한 배출부하량을 본 연구에서 실측한 유달부하량과 비교한 결과 유달율이 모든 수질 항목에서 100%를 넘는 것으로 나타나 영농기 농촌 소유역에 적용하여 오염부하를 평가하기에는 한계가 있을 것으로 판단된다. 향후 농촌 유역의 특성과 영농활동을 고려한 시기별 비점오염 물질의 유출 기작에 대한 연구가 더욱 진행되어야 할 것으로 판단된다.