• 제목/요약/키워드: Single-Index-Model

검색결과 265건 처리시간 0.028초

두꺼비 서식지 적합성 지수(HSI) 모델개발을 위한 연구 (A Study on the Development of "Bufo gargarizans" Habitat Suitability Index(HSI))

  • 조근영;구본학
    • 한국환경복원기술학회지
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    • 제25권2호
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    • pp.23-38
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    • 2022
  • This study investigates the characteristics and physical habitat requirements for each Bufo gargarizans life history through a literature survey. After deriving variables for each component of Bufo gargarizans, in order to reduce regional deviations from eight previously studied literature research areas for deriving the criteria for variables, a total of 12 natural habitats of Bufo gargarizanss are selected as spatial ranges by selecting four additional sites such as Umyeonsan Ecological Park in Seoul, Wonheungibangjuk in Cheongju in the central region, Changnyeong Isan Reservoir in the southern region, and Mangwonji in Daegu. This study presents Bufo gargarizans SI, a species endemic to Korea, whose population is rapidly declining due to large-scale housing site development and road development, and develops a Bufo gargarizans HSI model accordingly to improve the function of the damaged Bufo gargarizans habitat and to present an objective basis for site selection of alternative habitat. At the same time, it provides basic data for adaptive management and follow-up monitoring. The three basic habitat requirements of amphibians, the physical habitat requirements of Bufo gargarizans, synthesized with shelter, food, and water, and the characteristics of each life history, are classified into five components by adding space and threats through literature research and expert advice. Variables are proposed by synthesizing and comparing the general characteristics of amphibians, among the previously studied single species of amphibians, the components of HSI of goldfrogs and Bufo gargarizans, and the ecological and physical environmental characteristics of Bufo gargarizans. Afterwards, through consultation with an amphibian expert, a total of 10 variables are finally presented by adjacent forest area(ha), the distance between spawning area and the nearest forest land(m), the soil, the distance from the wetland(m), the forest layered structure, the low grassland space, the permanent wetland area(ha), shoreline slope(%), PH, presence of predators, distance from road(m), presence or absence of obstacles. n order to derive the final criteria for each of the 10 variables, the criteria(alternative) for each variable are presented through geographic information analysis of the site survey area and field surveys of the previously studied literature research area. After a focus group interview(FGI) of 30 people related to the Bufo gargarizans colony in Cheongju, a questionnaire and in-depth interviews with three amphibians experts are conducted to verify and supplement the criteria for each final variable. Based on the finally developed Bufo gargarizans HSI, the Bufo gargarizans habitat model is presented through the SI graph model and the drawing centering on the Bufo gargarizans spawning area

Along and across-wind vibration control of shear wall-frame buildings with flexible base by using passive dynamic absorbers

  • Ivan F. Huergo;Hugo Hernandez-Barrios;Roberto Gomez-Martinez
    • Wind and Structures
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    • 제38권1호
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    • pp.15-42
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    • 2024
  • A flexible-base coupled-two-beam (CTB) discrete model with equivalent tuned mass dampers is used to assess the effect of soil-structure interaction (SSI) and different types of lateral resisting systems on the design of passive dynamic absorbers (PDAs) under the action of along-wind and across-wind loads due to vortex shedding. A total of five different PDAs are considered in this study: (1) tuned mass damper (TMD), (2) circular tuned sloshing damper (C-TSD), (3) rectangular tuned sloshing damper (R-TSD), (4) two-way liquid damper (TWLD) and (5) pendulum tuned mass damper (PTMD). By modifying the non-dimensional lateral stiffness ratio, the CTB model can consider lateral deformations varying from those of a flexural cantilever beam to those of a shear cantilever beam. The Monte Carlo simulation method was used to generate along-wind and across-wind loads correlated along the height of a real shear wall-frame building, which has similar fundamental periods of vibration and different modes of lateral deformation in the xz and yz planes, respectively. Ambient vibration tests were conducted on the building to identify its real lateral behavior and thus choose the most suitable parameters for the CTB model. Both alongwind and across-wind responses of the 144-meter-tall building were computed considering four soil types (hard rock, dense soil, stiff soil and soft soil) and a single PDA on its top, that is, 96 time-history analyses were carried out to assess the effect of SSI and lateral resisting system on the PDAs design. Based on the parametric analyses, the response significantly increases as the soil flexibility increases for both type of lateral wind loads, particularly for flexural-type deformations. The results show a great effectiveness of PDAs in controlling across-wind peak displacements and both along-wind and across-wind RMS accelerations, on the contrary, PDAs were ineffective in controlling along-wind peak displacements on all soil types and different kind of lateral deformation. Generally speaking, the maximum possible value of the PDA mass efficiency index increases as the soil flexibility increases, on the contrary, it decreases as the non-dimensional lateral stiffness ratio of the building increases; therefore, there is a significant increase of the vibration control effectiveness of PDAs for lateral flexural-type deformations on soft soils.

The Prognostic Value of the Charlson's Comorbidity Index in Patients with Prolonged Acute Mechanical Ventilation: A Single Center Experience

  • Song, Seung Eon;Lee, Sang Hee;Jo, Eun-Jung;Eom, Jung Seop;Mok, Jeong Ha;Kim, Mi-Hyun;Kim, Ki Uk;Lee, Min Ki;Lee, Kwangha
    • Tuberculosis and Respiratory Diseases
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    • 제79권4호
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    • pp.289-294
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    • 2016
  • Background: The aim of our study was to evaluate the prognostic value of Charlson's weighted index of comorbidities (WIC) in patients with prolonged acute mechanical ventilation (PAMV, ventilator care ${\geq}96$ hours). Methods: We retrospectively enrolled 299 Korean PAMV patients who were admitted in a medical intensive care unit (ICU) of a university-affiliated tertiary care hospital between 2008 and 2013. Survivors were defined as patients who survived for 60 days after ICU admission. Results: The patients' mean age was $65.1{\pm}14.1$ years and 70.6% were male. The mean ICU and hospital length of stay was $21.9{\pm}19.7$ and $39.4{\pm}39.1$ days, respectively. In addition, the 60-day mortality rate after ICU admission was 35.5%. The mean WIC was $2.3{\pm}1.8$, with significant differences between nonsurvivors and survivors ($2.7{\pm}2.1$ vs. $2.1{\pm}1.7$, p<0.05). The area under the curve of receiver-operating-characteristics curve for WIC was 0.593 (95% confidence interval [CI], 0.523-0.661; p<0.05). Based on Kaplan-Meier curves of 60-day survival, WIC ${\geq}5$ had statistically lower survival than WIC <5 (logrank test, p<0.05). In a multivariate Cox proportional hazard model, WIC ${\geq}5$ was associated with poor prognosis (hazard ratio, 1.901; 95% CI, 1.140-3.171; p<0.05). The mortality rate of patients with WIC ${\geq}5$ was 54.2%. Conclusion: Our study showed a WIC score ${\geq}5$ might be helpful in predicting 60-day mortality in PAMV patients.

우리나라 성인의 인슐린 저항성과 관련된 영양소 및 식품군 섭취: 제 4기 국민건강영양조사 자료를 활용하여 (The relationship between intake of nutrients and food groups and insulin resistance in Korean adults: Using the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009))

  • 송수진;백희영;송윤주
    • Journal of Nutrition and Health
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    • 제46권1호
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    • pp.61-71
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    • 2013
  • The aim of this study was to examine the relationship between dietary variables and the prevalence of insulin resistance (IR) in middle-aged Korean adults using data from the 2007-2009 Korea National Health and Nutrition Examination Survey. Because IR is closely linked with metabolic syndrome, subjects were divided into three groups according to symptoms of metabolic syndrome: the 'Normal group' without any symptoms, the 'Risk group' with one or two symptoms, and the Metabolic syndrome (MetS) group' with three or more symptoms. Subjects between the ages of 30 and 65 years with no prior diagnosis or treatment for diabetes, hypertension, or dyslipidemia were selected. The number of subjects per group was as follows: 2,085 adults in the Normal group, 3,699 adults in the Risk group, and 1,160 adults in the MetS group. Metabolic syndrome was defined according to Adult Treatment Panel III criteria with modified waist circumference cutoff values (men ${\geq}$ 90 cm, women ${\geq}$ 85 cm). Subjects with HOMA-IR > 2.0 were classified as IR. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated using the following formula: (fasting plasma glucose ${\times}$ fasting plasma insulin)/22.5. Nutrients and food groups intake were obtained from a single 24-hour recall. Subjects with IR in the Normal group were more obese and less physically active than non-IR subjects. In the MetS group, subjects with IR were more obese and had a lower prevalence of smoking and drinking, compared with non-IR subjects. Men with IR in the Normal group had a tendency to consume more oils and sugars than non-IR men, while women with IR in the same group had higher intake of carbohydrate, dietary glycemic index, and dietary glycemic load than non-IR women. Women with IR in the Risk group had lower energy intake but higher intake of oils and sugars than non-IR women. In the MetS group, consumption of fruits was higher in subjects with IR than in non-IR subjects. In conclusion, findings of this study suggest that dietary carbohydrate intake, including glycemic index, may be associated with IR in healthy women. Further research in prospective cohort studies in order to examine the effects of dietary carbohydrate on IR incidence will be necessary.

공적 이전과 사적 이전의 빈곤 감소 효과 분석 : 기초생활보장제도 도입 이후를 중심으로 (An Analysis on the Anti-poverty Effectiveness of Public and Private Income Transfers; After the Enactment of National Basic Livelihood Security Act)

  • 홍경준
    • 한국사회복지학
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    • 제50권
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    • pp.61-85
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    • 2002
  • 이 연구의 목적은 기초생활보장제도의 도입으로 대표되는 최근의 국가복지제도 변화가 사회성원들의 복지욕구에 대한 공적 이전과 사적 이전의 효과를 어떤 식으로 변모시켰는지를 경험적으로 분석하는 것이다. 이러한 목적을 달성하기 위해 이 연구에서는 이전 소득의 원천을 기준으로 공적 이전과 사적 이전을 구분하고, 각각의 빈곤 감소 효과를 분석하는 접근 방식을 택한다. 즉, 기초생활보장제도의 시행을 반영하고 있는 2001년도 도시가계자료를 활용하였으며, 소득의 이전을 개인 간 혹은 가족 간에 이루어지는 사적 이전과 사회보장정책을 통해 이루어지는 공적 이전으로 구분하였으며, 각각의 빈곤 감소 효과를 효과성과 효율성 지표를 활용하여 비교했다. 그 결과, 두 가지의 흥미로운 사실이 발견되었다. 첫째, 선행연구들과 마찬가지로 여전히 사적 이전이 공적 이전보다 더 큰 빈곤 감소 효과를 가지지만, 그 격차는 상당히 완화되었다. 둘째, 사적 이전과 공적 이전의 빈곤 감소 효과는 가구 유형에 따라 달리 나타난다. 공적 이전의 확대 혹은 사적 이전의 축소가 이러한 분석결과를 가져왔겠지만, 이 연구에서는 기초생활보장제도의 도입으로 대표되는 공적 이전의 확대가 더 큰 영양을 미쳤을 것이라고 가정한다. 한편, 가구유형에 따라 공적 이전과 사적 이전의 빈곤 감소 효과가 상이하게 나타난다는 분석결과는 빈곤정책의 수립에 있어 빈곤계층의 다양성을 고려하는 것이 중요하다는 점을 다시 한번 일깨우는 것일 뿐 아니라, 사적 이전으로 대표되는 연복지의 제공논리에 대한 보다 상세한 분석의 필요성을 제기한다.

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취수 수심이 합천호의 수온성층과 방류 수온에 미치는 영향 모델링 (Modeling the Effect of Intake Depth on the Thermal Stratification and Outflow Water Temperature of Hapcheon Reservoir)

  • 정선아;김혜지;이혜숙
    • 환경영향평가
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    • 제32권6호
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    • pp.473-487
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    • 2023
  • 1970~1980년대 준공된 우리나라의 다목적댐 저수지에는 발전방류를 위한 고정식 취수구가 심층에 설치되어 있어 일부 댐 하류에서는 냉수 방류에 의한 농작물 냉해, 안개 일수 증가 등의 문제점이 제기된 바 있다. 본 연구에서는 고정식 취수구를 통해 심층 취수가 이루어지고 있는 합천호를 대상으로 취수 수심이 저수지의 수온 성층 구조와 방류 수온에 미치는 영향을 분석하였다. 3차원 수리수질모형인 AEM3D를 이용하여 합천호의 연직 수온 분포를 재현하고 계절별 수온성층 구조를 분석하였으며, 수문 조건에 따른 수온성층 변화를 비교 분석하기 위하여 풍수해와 갈수해를 대상으로 모델링 하였다. 또한 취수심 변경 시나리오를 적용함으로써 취수 수심이 수온성층 구조에 미치는 영향을 분석하였다. 모의 결과 심층 취수를 표층 취수로 변경할 경우 수온약층의 형성 위치가 풍수해 6.5 m, 갈수해 6.8 m 감소하여 더 얕은 수심에 형성될 것으로 분석되었다. 또한 수체 안정도 지수인 Schmidt Stability Index (SSI)와 Buoyancy frequency (N2)가 증가하여 수온성층 강도가 증가하는 것으로 나타났다. 표층 취수시 연평균 방류수온이 풍수해 3.5℃, 갈수해 5.0℃ 증가하여 하류하천의 영향은 감소하나, 호내의 저수온층 수체적과 수온성층 강도가 증가하므로 추후 수질관리를 위해 취수심을 댐 운영의 주요인자로 고려해야 할 것으로 판단된다.

댐 펄스방류로 인한 하천의 지형변화 수치모의 분석(영주댐 중심으로) (Numerical analysis of geomorphic changes in rivers due to dam pulse discharge of Yeongju Dam)

  • 백태효;장창래;이경수
    • 한국수자원학회논문집
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    • 제56권12호
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    • pp.871-881
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    • 2023
  • 본 연구에서는 영주댐 하류 하천을 대상으로 2차원 수치모형인 Nays2DH를 적용하여 펄스방류 등 다양한 유량 조건에서 하류 하천의 역동성을 파악하기 위해 하도의 지형변화 특성 및 하상기복지수를 분석하였다. 수치모의에 적용되는 유량패턴은 등류 흐름, 정규화된 단일홍수, 펄스방류, 그리고 정규화된 펄스방류 등 4개의 유형이다. 수치모의 결과, 정규화를 적용한 펄스방류 조건일 때 하상고 및 하도의 변화가 가장 큰 것으로 나타났다. 총 하상 변화량은 등류 흐름 조건일 때 29.88 m, 정규화된 단일 홍수 조건일 때 27.46 m, 펄스 방류일 때 29.63 m 그리고 정규화된 펄스 방류일 때 31.87 m로이며, 이 조건에서 세굴과 퇴적의 변동 폭이 가장 크게 나타났다. 하상기복지수(BRI)를 분석한 결과, 등류 조건, 펄스방류, 그리고 정규화된 펄스방류 조건은 시간이 지날수록 BRI가 증가한다. 그러나, 정규화된 단일홍수에서는 첨두유량(14 hrs) 이후 30 hrs 까지 BRI가 급격하게 증가하지만, 그 이후부터는 증가 폭이 점점 감소하고, 56 hrs부터는 감소하였다. 수치모의가 끝날 때(72 hrs) BRI는 등류일 때 2.95, 정규화된 단일홍수일 때 3.31, 펄스방류일 때 3.34, 정규화된 펄스방류일 때 3.78이다. 따라서, 정규화된 펄스방류가 단일홍수나 등류보다 더 큰 역동성을 줄 수 있고, 하류로 갈수록 역동성이 커지면서 댐 하류하천의 환경개선에 효과를 가져올 수 있을 것으로 기대한다.

A Promoter SNP (rs1800682, -670C/T) of FAS Is Associated with Stroke in a Korean Population

  • Kang, Sung-Wook;Chung, Joo-Ho;Kim, Dong-Hwan;Yun, Dong-Hwan;Yoo, Seung-Don;Kim, Hee-Sang;Seo, Wan;Yoon, Jee-Sang;Baik, Hyung-Hwan
    • Genomics & Informatics
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    • 제8권4호
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    • pp.206-211
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    • 2010
  • The Fas (TNF receptor superfamily, member 6) (FAS)/FAS ligand (FASLG) interaction plays a central role in the regulation of programmed cell death. FAS and FASLG polymorphisms in promoter regions affect transcriptional activities. To investigate whether FAS and FASLG polymorphisms are associated with the development and clinical phenotypes of stroke, 2 promoter single nucleotide polymorphisms (SNPs) in FAS (rs1800682, -670C/T) and FASLG (rs763110, -844C/T) were selected and genotyped by direct sequencing in 220 stroke patients [107 ischemic stroke (IS), 77 intracerebral hemorrhage (ICH), and 36 subarachnoid hemorrhage (SAH)] and 369 control subjects. For the analysis of clinical symptoms, all stroke patients were divided into 3 clinical phenotypes according to the respective results of the National Institutes of Health Stroke Survey (NIHSS) and the Modified Barthel Index (MBI) and the presence or absence of complex regional pain syndrome (CRPS). The SNPStats, SNPAnalyzer, and Helixtree programs were used to analyze the genetic data. Multiple logistic regression models (codominant, dominant, and recessive) were used to estimate odds ratios (ORs), 95% confidence intervals (CIs), and p-values. The promoter SNP rs1800682 was associated with stroke in the codominant (OR=0.48, 95% CI=0.25-0.94, p=0.04) and dominant models (OR=0.51, 95% CI=0.30-0.87, p=0.011). However, a FASLG SNP (rs763110) was not in Hardy-Weinberg equilibrium (p<0.05). In the analysis of stroke types, rs1800682 was associated with IS in the codominant (OR=0.30, 95% CI=0.12-0.74, p=0.025), dominant (OR=0.44, 95% CI=0.23-0.88, p=0.018), and recessive models (OR=0.45, 95% CI=0.21-0.99, p=0.042). The genotype frequencies of rs1800682 were different between ICH and controls in the dominant model (OR=0.49, 95% CI=0.26-0.94, p=0.031) but not between SAH and controls. In the analysis of clinical symptoms, however, rs1800682 was not related to the 3 clinical phenotypes (NIHSS, MBI, and CRPS). These results suggest that a promoter SNP (rs1800682, -670C/T) in FAS may be associated with the development of stroke in the Korean population.

Single Nucleotide Polymorphisms in the Gc Gene for Vitamin D Binding Protein in Common Cancers in Thailand

  • Maneechay, Wanwisa;Boonpipattanapong, Teeranut;Kanngurn, Samornmas;Puttawibul, Puttisak;Geater, Sarayut Lucien;Sangkhathat, Surasak
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3339-3344
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    • 2015
  • Background: This case-control study aimed to determine if there were any associations between the two single nucleotide polymorphisms (SNPs) in Gc, rs7041 (Asp416Glu) and rs4588 (Thr420Lys) and 3 common cancers (breast, lung and colorectal) in Thai patients. Materials and Methods: Two hundred and eighty two colorectal, 101 breast and 113 lung cancer patients were recruited from one institute during 2011-2013. The controls were age-matched volunteers who had a negative history of index cancers. In addition, vitamin D levels were compared among different genotypes in the 2 SNPs. Results: The minor allele frequencies of rs7041 (G) and rs4588 (A) were 0.32 and 0.24, respectively. Under the dominant model, the study found significant associations between minor-allele genotypes of the SNP rs7041 (TG/GG) and lung cancer (odds ratio [OR] 1.78, 95% CI 1.05-3.03). When subgroup analysis was performed according to sex and age at diagnosis, the study found that the minor-allele genotypes of rs7041 (TG/GG) were significantly associated with colorectal cancer in patients whose age at diagnosis was more than 60 years (OR 1.67, 95%CI 1.06-2.61) and the minor-allele genotypes of rs4588 (CA/AA) were significantly associated with colorectal cancer in males aged 60 years or less (OR 2.34, 95%CI 1.25-4.37). When SNP combinations (rs7041-rs4588) were examined, the TT-CA combination had a significant protective association with lung cancer (OR 0.44, 95% CI 0.22-0.85). On evaluation of serum 25(OH)D levels in 205 individuals without cancer (males 144, females 61), the proportion of subjects with low serum vitamin D (< 20 ng/ml) in those harboring CA or AA genotypes of rs4588 (41.7%) was significantly higher than the CC genotype (15.5%, p-value < 0.01). Conclusions: Genetic polymorphisms in Gc were associated with lung and colorectal cancers in Thai patients. Lower serum 25(OH)D in minor variants of rs4588 may explain this association.

식품 및 음식의 다량영양소 구성 성분에 따른 혈당 반응 연구 (Effects of macronutrients in mixed meals on postprandial glycemic response)

  • 박미현;정상진;심재은;장성희;남기선
    • Journal of Nutrition and Health
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    • 제51권1호
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    • pp.31-39
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    • 2018
  • 본 연구에서는 동일한 끼니에 섭취한 각 식품 및 음식의 영양성분 중 에너지에 기여하는 다량영양소인 탄수화물, 지방, 단백질과 식이섬유소가 혈당 반응에 어떠한 영향을 주는지를 알아보고자 하였다. 20대 성인 남녀를 대상으로 총 62가지의 단일 또는 여러 가지 단일 식품으로 구성된 혼합 식사 섭취 후 2시간 동안의 혈당을 측정하여 혈당곡 선하면적을 계산하였다. 그 결과 일반적으로 탄수화물 함량이 증가하면 혈당곡선하면적이 증가하였다. 그러나 탄수화물 이외에 식품 및 음식에 함유된 지방, 식이섬유소 등의 함량도 혈당곡선하면적에 영향을 준 것을 확인할 수 있었다. 탄수화물, 단백질, 지방, 식이섬유소의 영양성분이 혈당곡선하면적에 미치는 영향을 분석한 결과 탄수화물(${\beta}=37.18$, p < 0.0001)은 혈당곡선하면적을 유의적으로 증가시켰고, 지방 (${\beta}=-32.70$, p = 0.0054), 식이섬유소 (${\beta}=-32.01$, p = 0.0486)는 유의적으로 감소시켰으며, 단백질 (${\beta}=-12.93$, p = 0.1657)은 혈당 반응에 유의적인 영향을 미치지 않았다. 본 연구는 식품 및 음식의 영양성분 중 탄수화물 함량만이 아닌 지방, 식이섬유소가 서로 상호작용하여 혈당 반응에 영향을 미치는 것을 확인하여 의미가 크다.