PURPOSES: Spalling is one of the primary problems that lead to the damage of concrete pavements. The purpose of the study is to analyze the impact range of spalling that occurred in an area of concrete pavement by applying a variety of nondestructive and destructive testing methods. METHODS: Spalling of the concrete pavement was categorized into four different sizes, 0 cm, 7.5 cm, 15 cm, and 30 cm. Nondestructive and destructive tests were performed at the point of spalling and 1 m away, respectively, and the obtained results were compared. The nondestructive tests included the electrical resistance test and the ultrasonic velocity test as well as strength tests by Schmidt hammer and concrete tester. The destructive tests included the direct compressive strength test and the chloride content test using field cored specimens. The test results helped in the analysis of the correlation between the current spalling damage condition and the expected damage acceleration. RESULTS: Based on the present study, the repair area and depth of spalling for a partial depth repair was suggested. It was also shown that the size of the spalling is highly correlated with the chloride content and the electrical resistance of the concrete pavement. CONCLUSIONS: The degree of spalling deterioration was found to be highly correlated with the chloride content and electrical resistance of the concrete pavement and based on the results, the extent of repair could be determined more quantitatively.

Batch adsorption tests were performed to evaluate the applicability of adsorption kinetic model by using hydrogel chitosan bead crosslinked with glutaraldehyde (HCB-G) for Cu(II) as cation and/or phosphate as anion. Pseudo first and second order model were applied to determine the sorption kinetic property and intraparticle and Boyd equation were used to predict the diffusion of Cu(II) and phosphate at pore and boundary-layer, respectively. According to the value of theoretical and experimental uptake of Cu(II) and phosphate, pseudo second order is more suitable. On comparison with the value of adsorption rate constant (k), phosphate kinetic was 2-4 times faster than that of Cu(II) at any experimental condition indicating the electrostatic interaction between NH3 + and phosphate is dominated at the presence of single component. However, when Cu(II) and phosphate simultaneously exist, the value of k for phosphate was sharply decreased and then the difference was not significant. Both diffusion models confirmed that the sorption rate was controlled by film mass transfer at the beginning time (t < 3 hr) and pore diffusion at next time section (t > 6 hr).

In this paper the potential of the principal component analysis(PCA) technique for the application of detecting leaks in water pipe networks was evaluated. For this purpose the PCA was conducted to evaluate the relevance of the calculated outliers of a PCA model utilizing the recorded pipe flows and the recorded pipe leak incidents of a case study water distribution system. The PCA technique was enhanced by applying the computational algorithms developed in this study which were designed to extract a partial set of flow data from the original 24 hour flow data so that the effective outlier detection rate was maximized. The relevance of the calculated outliers of a PCA model and the recorded pipe leak incidents was analyzed. The developed algorithm may be applied in determining further leak detection field work for water distribution blocks that have more than 70% of the effective outlier detection rate. However, the analysis suggested that further development on the algorithm is needed to enhance the applicability of the PCA in detecting leaks by considering series of leak reports happening in a relatively short period.

본 연구는 밀폐형 식물생산시스템에서 인공광원과 배지 종류에 따른 상추의 생육 특성을 조사하기 위해 수행되었다. 상추 종자는 5종류의 배지인 urethane sponge(US), rockwool(RW), Q plug(QP), TP-S2(TP)와 PU-7B(PU)가 충진된 128구 플러그 트레이에 파종하였다. 상추 종자의 발아율은 파종 후 12일까지 조사하였다. 상추 묘는 파종 후 13일째에 재순환 담액식 수경재배 시스템을 이용하여 EC 2.0dS·m-1, pH 6.5와 온도 25±1oC인 밀폐형 식물생산시스템에 정식하였다. 광원은 형광등과 RB LEDs(red:blue=7:3)를 이용하여 광주기 14/10(명기/암기), 광도 150±10μmol·m-2·s-1 PPFD로 설정했다. 상추의 초기 발아율은 TP에서 가장 높았다. 최종 발아율과 평균 발아 수는 RW, QP 및 TP 배지에서 유의적으로 높았다. 초장, 엽장, 엽폭, 엽면적, 지상부의 생체중, 건물중 모두 RB LED의 QP에서 유의성 있게 높은 값을 나타냈다. 엽수, 지하부의 생체중과 건물과 SPAD는 RB LED의 QP와 TP에서 가장 좋았고, 근장은 RB LED의 TP에서 가장 길었다. 따라서 밀폐형 식물생산시스템에서 RB LED가 상추의 생육이 우수하였으며, QP와 TP가 상추의 발아율과 생육에 효과적인 것으로 나타났다. 뿐만 아니라, 밀폐형 식물생산시스템에서 상추 생산 시 신개발 배지인 TP 배지의 적용가능성을 확인하였다.

Law reacts to the progression of scientific technology in the end. Though conservative, changes are beginning to take place due to Artificial Intelligence (AI). AI is automating conventional legal works, creating a new industry namely Legal-Tech. This paper investigates the characteristics and flow of legal-AI and computational law while focusing on the applicability of AI to international law. Mainly, the paper reviews three critical areas: dispute resolution, trial prediction, and machine translation, respectively. International law has different characteristics than the domestic law applied in each country. Unlike domestic law, international law has not been aggregated from a pandect, and it is a still daunting task to draw any meaningful insights for further analysis due mainly to limited data (i.e., trial cases and precedents). Nevertheless, AI is already penetrating the legal ecology system, and international law would eventually accept the influx of such changes exhibiting greater force.

확률형 아이템은 부분 유료화 게임모델에서 게임사의 수익 창출을 위한 장치로서 도입되었으며, 게임 이용자가 현금 또는 게임머니 등을 투입(구입)한 후 우연 또는 확률에 따라 일정한 보상 아이템을 획득하는 구조를 기본적인 특징으로 하고 있다. 확률형 아이템은 오락으로서의 게임의 흥미를 증대시킬 수 있다는 장점이 있으나, 한편으로 는 사행성을 부추기는 측면이 있고 특히 미성년자에게 유해한 영향을 미칠 수 있으므로, 일정한 수준에서 그 도박적⋅사행적 성격을 제한하기 위한 조치가 필요하다. 아직 국내에서는 확률형 아이템에 대한 규제가 미비한 실정이며 게임업계 자체적으로 자율규제를 통한 모니터링을 진행하고 있으나 자율규제의 적용범위의 한계, 이행 강제수단의 미비 등 실효성에 대한 의문이 지속적으로 제기되고 있다. 해외에서는 일찍이 확률형 아이템을 도박으로 규율 할 수 있을지를 둘러싸고 논의가 활발히 이루어졌다. 영국, 미국, 프랑스, 독일, 네덜란드, 호주 등 대부분의 국가에서는 확률형 아이템이 도박에 해당하기 위해서는 확률에 의해 획득한 아이템에 현실적인 경제적 가치가 인정되어야 하는데, 확률형 아이템을 통해 획득한 아이템이 게임 외부에서 거래될 수 있는 가능성이 없는 경우에는 그 자체에 경제적 가치가 있다고 보기는 어렵다는 입장이 주도적인 것으로 보인다. 반면 벨기에에서는 게임 아이템의 거래 가능성과는 무관하게 확률형 아이템이 도박에 해당한다는 유권해석이 등장하였고 이에 따른 제재가 이루어지고 있는 실정이다. 우리나라 형법상 도박은 2인 이상이 재물 또 는 재산상 이익을 걸고 우연에 의하여 재물 또는 재산상 이익의 득실을 결정하는 것을 의미한다. 확률형 아이템이 도박에 해당하는지를 판단함에 있어 핵심적인 부분은 획득한 아이템이 ‘재물 또는 재산상 이익’에 해당한다고 볼 수 있는지 및 투입한 금전의 가치보다 획득한 아이템의 가치가 낮은 경우에 ‘손실’이 발생하였다고 볼 수 있는지의 문제일 것이다. 게임 아이템의 경제적 가치 인정 여부 및 가치 측정 가능성에 관하여는 부정설, 투입설, 거래 가능성설, 거래 활성화설 등 다양한 층위의 견해가 제시되고 있고 모두 일견 타당한 논거를 갖추고 있는 것으로 보인다. 한편 확률형 아이템을 어떠한 수단과 방법으로 규율할 것인지에 대하여는 정부 차원의 강제성이 있는 규제와 게임업계 내부의 자율적인 규제를 주장하는 입장이 대립되고 있고 두 가지 방안의 장점을 적절히 조화하여야 한다는 절충안도 제시되고 있다. 규제의 실효성 및 유연성이라는 측면에서 더욱 풍부 한 논의가 필요할 것으로 생각된다. 다양한 논의를 통한 사회적 합의가 선행될 때 비로소 확률형 아이템에 대한 합리적인 수준의 규제가 도입될 수 있을 것이다.

This study was conducted to determine the applicability of the shoot growth model to cut roses grown at high temperatures. Two cultivars of cut roses, ‘Antique Curl’ and ‘Beast’, were cultivated in growth chambers set to night/day temperatures of 24/20°C for the control group and 32/28°C for the treatment group. The shoot growth model, which resulted in high coefficients of determination (R2 = 0.80 and 0.62, respectively, for ‘Antique Curl’ and ‘Beast’), was a good predictor of the decrease in the growth of rose shoots for both treatment groups. Although the model produced good results for both the control and treatment groups of ‘Antique Curl’, the accuracy of the model can be improved by using the modified leaf area at the harvest stage. From these results, the model was confirmed to perform well for predicting a decrease in productiveness and quality in cut roses cultivated during summer under high temperatures.

현재 기준개념으로 개발하여 상용화 단계에 있는 심층 동굴 처분기술에 대한 대안으로서 지질학적 조건이 더 안정적인 지하 3~5 km의 심도에 사용후핵연료를 포함한 고준위폐기물을 처분하는 심부시추공 처분기술의 국내 적용 가능성을 예비 평가 하였다. 이를 위하여 심부시추공 처분개념의 기술적 적용성 분석에 필요한 국내 기반암 분포특성 및 심부시추공 처분부 지적합성 평가 기술 분석과 대구경 심부시추기술을 평가하였다. 이들 분석결과를 바탕으로 심부시추공 처분시스템 설계 기준 및 요건에 적합한 심부시추공 처분용기 및 밀봉시스템 개념을 설정하여 예비 기준 심부시추공 처분 개념을 도출하였다. 그리고 도출된 예비 기준 처분시스템에 대하여 열적 안정성 및 그래픽 처분환경에서의 처분공정 모사 등 다양한 성능평가를 수행하고 이들을 종합하여 심부시추공 처분시스템의 국내 적용성에 대하여 다양한 관점에서의 예비평가를 수행하였다. 결론적으로, 심부시추공 처분시스템은 처분심도와 단순한 방법으로 인하여 안전성 및 경제적 타당성 측면에서 많은 장점이 있지만, 불확실성을 줄이고 인허가를 획득하기 위해서는 이 기술에 대한 현장실증이 필수적이다. 본 연구결과는 사용후핵연료 관리 국가정책 수립을 위한 공학적 근거자료로 활용이 가능하며, 심부시추공 처분기술에 관심을 갖는 방사성폐기물 관리 이해당사자들에게 필요한 정보자료로 제공될 수 있다.

PURPOSES: In this paper, the packing degrees of binary granular mixtures under vibration compaction were simulated by using DEM with spherical particles to evaluate the applicability of the DEM for aggregate packing degree estimation. METHODS: The packing degrees of fine particles, coarse particles, and their mixture with different fine particle fractions were evaluated in DEM simulation for given various material property conditions. In order to check the validity of estimated packing degrees of particle mixtures, analytical model such as Furnas model that is capable of considering wall effect and loosening effect. RESULTS : DEM with spherical particles showed good agrement with analytical solution in terms of the packing degrees of binary granular mixtures with various fine particle fractions for most of conditions. Also, it was found that not the vibration amplitude but the ratio of particle diameter with vibration amplitude should be considered to explain the susceptibility of particle packing degree with vibration amplitude for the same acceleration condition and that the reduction in elastic modulus to shorten computational simulation time should be carefully considered when the packing degree is the most important concern. CONCLUSIONS: It was concluded that DEM with spherical particles are good enough to estimate the packing degree of binary granular particles for most of conditions. However, the effect of inter-particle frictions between fine and coarse particles have to be studied further in order to clarify the issue relating poor predictions for high inter-particle friction conditions.

In this study, various physical cleaning methods such as physical washing and osmotic backwash, were performed to understand membrane fouling characteristics by employing real secondary wastewater effluent (SWWE). In addition, microfiltration (MF) and ultrafiltration (UF) pretreatments were compared to maximize removal of organic matter and to control membrane fouling efficiently. Organic foulants deposited on the active layer of FO membrane were observed by fouling behavior test. The relationship between concentrations of natural organic matter and membrane fouling was also investigated from the bench-scale FO tests. Finally, by quantitative analysis of correlations between foulants and fouling reversibility with the modified fouling index (MFI), we identified the applicability of MFI in predicting FO intake water fouling potential.

PURPOSES : The objective of this study was to evaluate the field applicability of chip seals using recycled aggregates by comparing performance between natural aggregates and recycled aggregates for chip seals. METHODS : In order to check the performance of chip seals using recycled and natural aggregates, Bitumen Bond Strength (BBS) test, Vialit and bleeding tests were carried out. Cationic emulsions (RS(C)-2 and latex modified RS(C)-2L) were used in the tests. Granite aggregates were used as the natural aggregate and recycled aggregate from road wastes were used as the recycled aggregate. The aggregate was used with uniform gradation between 10 mm and 4.75 mm to clearly compare the performance difference between natural and recycled aggregates. RESULTS : Test results showed that the aggregate retention was low for both natural and recycled aggregates when applying RS(C)-2 (unmodified emulsion), but there was almost no difference between them when applying RS(C)-2L and RS(C)-2L-1 (modified emulsion) in the Vialit test results. In the bleeding tests, there was no bleeding for both natural and recycled aggregates when applying RS(C)-2 and RS(C)-2L. CONCLUSIONS: It was possible to apply chip seals using recycled aggregates in the field because the chip seals with recycled aggregates and RS(C)-2L (modified emulsion) showed aggregate retention similar to that of natural aggregates, and there was no bleeding.

In this study, the applicability of biodiesel fuel was investigated as an hopeful alternative fuel for a compression ignition engine. The exhausted smoke emission of biodiesel fuel was reduced remarkably in comparison with commercial diesel fuel, that is, it was reduced approximately 64% at 2500 rpm, full load condition. And, torque, power and brake specific energy consumption rate did not showed significant differences. But, NOx emission of biodiesel fuel was slightly increased in comparison with the commercial diesel fuel. Generation of CO2 is considerably reduced by photosynthetic action in the course of growing biomass series plants, the material for biodiesel fuel.