• 한국축산식품학회지
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• 제36권4호
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• pp.547-557
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• 2016

This review discusses the status, antimicrobial mechanisms, application, and regulation of natural preservatives in livestock food systems. Conventional preservatives are synthetic chemical substances including nitrates/nitrites, sulfites, sodium benzoate, propyl gallate, and potassium sorbate. The use of artificial preservatives is being reconsidered because of concerns relating to headache, allergies, and cancer. As the demand for biopreservation in food systems has increased, new natural antimicrobial compounds of various origins are being developed, including plant-derived products (polyphenolics, essential oils, plant antimicrobial peptides (pAMPs)), animal-derived products (lysozymes, lactoperoxidase, lactoferrin, ovotransferrin, antimicrobial peptide (AMP), chitosan and others), and microbial metabolites (nisin, natamycin, pullulan, ε-polylysine, organic acid, and others). These natural preservatives act by inhibiting microbial cell walls/membranes, DNA/RNA replication and transcription, protein synthesis, and metabolism. Natural preservatives have been recognized for their safety; however, these substances can influence color, smell, and toxicity in large amounts while being effective as a food preservative. Therefore, to evaluate the safety and toxicity of natural preservatives, various trials including combinations of other substances or different food preservation systems, and capsulation have been performed. Natamycin and nisin are currently the only natural preservatives being regulated, and other natural preservatives will have to be legally regulated before their widespread use.

• Structural Engineering and Mechanics
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• 제58권1호
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• pp.39-58
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• 2016

Since the publication of ACI 318-02, the concrete capacity design (CCD) method has been used to determine the resistance of unreinforced concrete anchors. The regulation of steel-reinforced anchors was proposed in ACI 318-08. Until ACI 318-08, the shear resistance of concrete breakout for an unreinforced anchor during an earthquake was reduced to 75% of the static shear strength, but this reduction has been eliminated since ACI 318-11. In addition, the resistance of a hairpin-reinforced anchor was calculated using only the strength of the steel, and a regulation on the dynamic strength was not given for reinforced anchors. In this study, shaking table tests were performed to evaluate the dynamic shear strength of unreinforced and hairpin-reinforced cast-in-place (CIP) anchors during earthquakes. The anchors used in this study were 30 mm in diameter, with edge distances of 150 mm and embedment depths of 240 mm. The diameter of the hairpin steel was 10 mm. Shaking table tests were carried out on two specimens using the artificial earthquake, based on the United States Nuclear Regulatory Commission (US NRC)'s Regulatory Guide 1.60, and the Northridge earthquake. The experimental results were compared to the current ACI 318 and ETAG 001 design codes.

• 한국조경학회지
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• 제39권1호
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• pp.35-45
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• 2011

서울의 도시경관은 경제성장과 함께 급속하게 성장하고 변화하였다. 서울시는 건축물 난립으로 인하여 경관이 훼손되는 것을 보호하기 위하여 고도지구를 지정하여 도시경관을 보전 관리하기 시작하였다. 도시경관을 보전하기 위한 최고고도지구 지정은 그 목적이 명확하고 규제가 단순하여 시행 및 관리가 용이하지만, 규제 높이에 대한 객관적인 근거가 부족하여 설득력이 부족하다. 또한 일률적인 규제로 인하여 획일적인 경관을 형성하고 재산권 제약 및 지역발전 저해 등으로 인하여 주민으로부터 민원을 발생시키고 있다. 이러한 문제를 해결하기 위하여 많은 연구가 진행되고 있으나, 여전히 일률적인 기준에 의하여 규제되고 있어 보다 객관적이고 합리적인 경관고도 기준 도출이 필요하다. 따라서 본 연구는 국립공원의 자연경관을 보호하기 위한 목적으로 지정되어 있는 북한산 인근의 최고고도지구를 사례 대상지로 선정하여 자연경관의 훼손을 최소화하면서 인공경관과 자연경관이 조화를 이룰 수 있는 경관고도를 제시하고자 하였다. 이를 위하여 문헌조사를 통한 경관고도 기준의 유형 중 절대높이 기준, 조망선 기준, 사선제한 기준에 대하여 파악하고, 경관고도 설정 기본 원칙을 수립하였으며, 북한산 인근의 최고고도지구의 현황 및 문제점을 파악한 후 강북구를 적용 대상지로 선정하여 설문조사를 통하여 우수 조망점과 조망축을 파악하였다. 문헌조사를 통하여 파악한 경관고도 기준의 유형을 기초로 하여 강북구 최고고도지구의 구역을 세분화함으로써 각 구역에 적합한 경관고도 기준을 도출하였다. 도출된 기준은 3차원 시뮬레이션을 통하여 적용해 봄으로써 최종 경관고도를 제시하였다.

• 한국국방경영분석학회지
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• 제1권1호
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• pp.111-129
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• 1975

U.S. Air Force Regulation 80-1 defines that a weapon system is composed of equipments, skills, and techniques, the composite of which ferns an instrument of combat. The complete weapon system includes all related facilities, equipments, materials, services, and personnels required for the operation of the system, so that the instrument of combat can be considered as a self-sufficient unit of striking power in its intended operational environment. Effectiveness of a weapon system can be expressed as a function of its liability, reliability and performance capability. Among these attributes which influence the weapon effectiveness, performance capability is considered to be the most critical factor for many weapon systems. In order to illustrate the application of the methodology of performance capability, a specific ease study on the effectiveness of Vulcan anti-air craft gun system is presented with special emphasis on hitting probability on moving targets, effects of artificial rounds dispersion, and several principles related to the deployment of the system. This thesis includes the thorough survey of the possibility of calculating the absolute value of hitting probability on moving targets, indicates that the effects of artificial rounds dispersion increase the value of probability only when the total number of rounds fired within fire range exceeds a certain critical number, and suggests that concentrated guns deployment is better than scattered deployment in order to obtain higher probability and lower average amount of rounds if it is assumed that the effects of counter-attack from enemy threats are not serious.

• 한국산업보건학회지
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• 제26권3호
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• pp.367-376
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• 2016

Objectives: The production and use of nanoparticles have been increased. In 2014 Workplace Survey Results, 335 companies produce and treat nanoparticls. However, lack of data on nano-toxicity and a method for risk management and regulation on nanoparticles and the standard test method are not sufficient. Protective equipment selection guidelines for nanoparticles are not established. It is required to carry out respirator efficiency test against nanoparticles. This study was performed to evaluate filtration efficiency and manikin-based total inward leakage of particle filtering mask using in Korean country challenged with silver nanoparticles. Methods: We investigated filtration efficiency and total inward leakage of 7 respirator with silver nanoparticle. Results: The geometric mean diameters of Silver nanoparticles were 30 nm and number concentration were about $10^6{\sharp}/cm^3$. Filtration efficiency of six of the seven particle filtering masks was more than 98% and one particle filtering masks filtration efficiency was 94.9%. The filtration efficiency of particle filtering masks to 20 nm silver nanoparticels was highest. Artificial breathing machine with manikin based total inward leakage were 7.6% ~ 42.3%. Conclusions: The results of this study nano-silver filter efficiency was high but the total inward leakage was higher than filter penetration. Therefore, education on how to wear a respirator should be demanded. Especially for workers handling nanoparticles and toxic material, user seal checking and fit test must be performed.

• 대한화장품학회지
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• 제49권4호
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• pp.349-354
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• 2023

자외선 차단제는 자외선을 차단 및 산란시켜 자외선으로부터 보호하는 제품으로 이제 화장품을 넘어서 생활필수품으로 자리 잡고 있다. 자외선 차단제 바르기는 일반적이면서도 손쉬운 자외선에 의한 피부 손상 예방법이다. 이러한 중요성에 따라 자외선 차단제 평가시험은 1978 년 Fod and Drug Administration (FDA)에서 규정을 마련한 이후, 현재는 International Organization For Standardization (ISO)에서 표준화된 방법까지 발전되었다. 더불어 물이나 땀 등 신체활동에 의한 자외선 차단제 손실을 평가하기 위해 국내 식약처와 ISO에서 내수성 자외선 차단지수 평가시험을 제정하고 있다. 그러나 지금까지의 내수성 자외선 차단지수 평가시험은 주로 일반 물을 사용한 시험 방법에 국한되어 있으며, 해변에서의 레저, 스포츠 및 여가활동에 의한 해수의 영향을 고려한 시험 방법은 아직 정립되지 않았다. 본 연구는 기존의 내수성 자외선 차단지수 평가시험 방법 가이드라인을 기반으로 일반 물, 인공 해수(소금물) 및 자연 해수(바닷물)에서의 내수성 자외선 차단지수를 비교하여 해양 레저, 스포츠 및 여가활동 등과 같은 실제 상황에서의 자외선 차단지수를 평가할 수 있는 방법에 대하여 조사하였다. 이러한 결과를 통해 일반 물과 인공 해수 및 자연 해수에서의 내수성 자외선 차단지수 평가시험의 차이를 비교하여 자연 해수를 이용한 내수성 자외선 차단지수 평가시험 방법을 제시할 수 있었다.

• 디지털융복합연구
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• 제18권5호
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• pp.17-23
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• 2020

AI 기술이 고도화됨에 따라 국내외에서 AI 로봇에 대한 법적 지위 및 규제 문제, 로봇등록제의 필요성이 대두되고 있다. AI 로봇의 형태 및 활동범위는 더 이상 한 국가내에 놓여진 하드웨어에 머물지 않을 것이므로, AI 로봇에 대한 정의 및 규제는 소프트웨어를 포함시킨 포괄적 개념으로 확장되어야하며, 이들에 대한 정보도 국제적으로 각국 정부가 안전하게 관리하고 공유할 수 있는 형태로 정의되어야한다. 본 연구는 이러한 관점에서 'AI 로봇'을 하드웨어와 소프트웨어를 포괄하는 AI 법인이라는 개념으로 확장시키고, (가칭) Juridical AI Chain이라는 허가형 블록체인을 이용해 AI 법인 등록제를 운영하는 방안을 제시한다. 블록체인은 각국 정부기관들의 관리 및 공유가 가능한 분산형 공유 장부이므로, 블록체인 기반 등록제의 운영은 AI 로봇의 상용화가 초래할 범세계적 문제들에 효과적으로 대처할 수 있는 방안이 될 것이다.

• Journal of Radiation Protection and Research
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• 제42권2호
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• pp.91-97
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• 2017

Background: A gamma energy identifying algorithm using spectral decomposition combined with smoothing method was suggested to confirm the existence of the artificial radio isotopes. The algorithm is composed by original pattern recognition method and smoothing method to enhance the performance to identify gamma energy of radiation sensors that have low energy resolution. Materials and Methods: The gamma energy identifying algorithm for the compact radiation sensor is a three-step of refinement process. Firstly, the magnitude set is calculated by the original spectral decomposition. Secondly, the magnitude of modeling error in the magnitude set is reduced by the smoothing method. Thirdly, the expected gamma energy is finally decided based on the enhanced magnitude set as a result of the spectral decomposition with the smoothing method. The algorithm was optimized for the designed radiation sensor composed of a CsI (Tl) scintillator and a silicon pin diode. Results and Discussion: The two performance parameters used to estimate the algorithm are the accuracy of expected gamma energy and the number of repeated calculations. The original gamma energy was accurately identified with the single energy of gamma radiation by adapting this modeling error reduction method. Also the average error decreased by half with the multi energies of gamma radiation in comparison to the original spectral decomposition. In addition, the number of repeated calculations also decreased by half even in low fluence conditions under $10^4$ ($/0.09cm^2$ of the scintillator surface). Conclusion: Through the development of this algorithm, we have confirmed the possibility of developing a product that can identify artificial radionuclides nearby using inexpensive radiation sensors that are easy to use by the public. Therefore, it can contribute to reduce the anxiety of the public exposure by determining the presence of artificial radionuclides in the vicinity.

• 한국컴퓨터정보학회논문지
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• 제27권5호
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• pp.29-36
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• 2022

본 논문에서는 DACON에서 제공하는 데이터셋을 기반으로 한 효과적인 농산물 가격 예측 모델을 제안한다. 이 모델은 XGBoost와 CatBoost 이며 Gradient Boosting 계열의 알고리즘으로써 기존의 Logistic Regression과 Random Forest보다 평균정확도 및 수행시간이 우수하다. 이러한 장점들을 기반으로 농산물의 이전 가격들을 기반으로 1주, 2주, 4주뒤 가격을 예측하는 머신러닝 모델을 설계한다. XGBoost 모델은 회귀 방식의 모델링인 XGBoost Regressor 라이브러리를 사용하여 하이퍼 파라미터를 조정함으로써 가장 우수한 성능을 도출할 수 있다. CatBoost 모델은 CatBoost Regressor를 사용하여 모델을 구현한다. 구현한 모델은 DACON에서 제공하는 API를 이용하여 검증하고, 모델 별 성능평가를 실시한다. XGBoost는 자체적인 과적합 규제를 진행하기 때문에 적은 데이터셋에도 불구하고 우수한 성능을 도출하지만, 학습시간, 예측시간 등 시간적인 성능 면에서는 LGBM보다 성능이 낮다는 것을 알 수 있었다.

• 분석과학
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• 제36권1호
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• pp.22-31
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• 2023

As the use of e-liquid cigarettes is rapidly increasing worldwide, it multiplies the potential risk undisclosed to the health of non- and smokers. To reduce the hazard, each country has its own set of regulations for controlling e-liquids. In Korea, the narrow definition of tobacco makes it difficult and have been steadily occurring tax evasion exploiting the difference in natural and artificial nicotine. Therefore, it is very important to distinguish source of nicotine for their regulation. To find biochemical discriminant markers, this study established analysis methods based on high-performance liquid chromatography coupled with diode array detector (HPLC-DAD) and high-performance liquid chromatography coupled with triple Quadrupole mass spectrometry (HPLC-MS/MS) for nicotine enantiomers and tobacco alkaloids targeted using the difference in pathways of nicotine biosynthesis and chemical synthesis. The method was validated by experimenting linearity (R² > 0.999), recovery (80.99-108.41 %), accuracy (94.11-109.73 %) and precision (0.04-8.27 %). Then, the results for discrimination of the nicotine obtained from analysis of 65 commercial e-liquid products available in Korean market was evaluated. The method successfully applied to the e-liquids and one sample labelled 'synthetic nicotine' for tax exemption was found to contain a natural nicotine product. This method can be used to determine whether an e-liquid product uses natural or artificial nicotine and monitor non-taxable e-liquid products. The method is more scientific than the existing one, which relies only on field evidence.