P2E(Play-to-Earn)게임은 기존의 게임과 달리 게임을 통해 아이템 NFT, 가상자산(토큰) 획득으로 게임 이용자가 수익을 얻을 수 있는 게임의 한 종류다.1) 2023년도 국내에서 P2E게임 관련 판례가 확정되었고, 이에 따라 해외와 달리 국내에서 P2E게임은 전면 금지되고 있다. 기존 선행연구 에서 지속적으로 비판받아왔듯이, P2E게임에서 가상자산이 활용된다고 하 여, 가상자산의 사행적 측면을 혼재시켜, P2E게임을 사행성 게임물로 곧장 판단하는 것은 오도다. P2E게임 상에서 아이템의 NFT화와 게임 내 토큰 활용 과정을 면밀히 재검토한 결과, 선행연구에서 밝히고 있는 법리상의 문 제점에 더하여, P2E게임의 우연성 해소 가능성, 사행성 게임물과 P2E게임 의 본질적 차이(기대값), P2E게임과 가상자산의 분리 등의 새로운 문제점 을 발견할 수 있었다. 이에 따라, 본고에서는 국내 P2E 게임의 전면 금지의 배경이 된 최근 2 개의 판례를 비판적 검토함과 동시에 P2E게임에 대한 국내 선행 연구를 정리한 뒤, 우리나라 가상자산이용자보호법과 그 토대가 되는 EU의 MiCA 법, 그리고 프랑스 국내법인 SREN법을 살펴 우리나라에서 향후 P2E게임 이 허용될 가능성을 검토하고 그 방향성에 대한 논의를 담았다.

블록체인 기술을 기반으로, 환금성이 있는 NFT(Non-fungible token) 또는 가상화폐가 게 임이용의 결과물로서 이용자에게 귀속되는 P2E (Play to Earn) 게임 모델이 새로이 등장하였다. 그러나 게임물관리위원회는 P2E 게임의 사행성 을 이유로 등급분류를 거부하거나 취소하여 국내 시장 유통을 금지하고 있다. 반면 우리나라를 제 외한 많은 국가들에서는 P2E 게임이 활발하게 이용되고 있어 게임위 판단의 근거를 검토할 필 요가 있다. 게임위는 법률상 사행성게임물에 대한 등급분 류를 거부하거나 취소할 수 있는데, 이때 사행성 게임물 판단을 위한 근거규정이 미비하다는 문제 가 있다. 사행성게임물은 법률상 사행행위(베팅, 배당, 경마 등)를 내용으로 하거나 게임의 결과가 우연적으로 결정되는 게임물로서 이용자의 자산 에 손익을 미치는 것으로 정의되는데, NFT 혹은 가상자산이 이용자의 자산에 이익이 된다는 이유 만으로 그 게임물의 내용과 상관없이 사행성게임 물로 규정하는 것은 잘못이다. 또한 이용자의 재 산상 손익을 끼칠 수 있는지에 대한 구체적인 판 단 기준을하위법령에위임하고있으나, 위임받은 법령과 게임위 내규에서는 별도로 다루지 않고 있어 판단기준에 공백이 있다. 한편 게임물의 사행성은 게임물의 등급분류에 영향을 미치는데, 사행성게임물이 아니라면 사행 성이 인정되더라도 등급분류에 따라 게임출시가 가능하다. 게임산업법은 사행적인 게임물의 환전 행위를금지하고있는데, P2E 게임의환전가능성 을 이유로 사행성게임물로 판단하는 것은 잘못된 적용이다. 더불어 경품 등의 제공을 통한 사행성 조장을 금지하고 있는데, P2E 게임 이용자에게 제공되는 결과물은 그 형태와 관계없이 경품 등 에 해당하므로 사행성을 조장한다고 볼 수 있다. 그러나 게임물의 사행성 판단에 대해서는 사회⋅ 경제적 상황과 업계종사자의 의견을 반영하여 탄 력적으로 규율하는 것이 바람직하다.

It has been known that the ability of Shiga toxinproducing Escherichia coli (STEC) to produce Stx2e in culture media plays a role in the diagnosis of edema disease and determination of subunit vaccine candidates in STEC isolates. To examine the efficiency of Stx2e production in several commercial media, a Stx2e-producing strain (KEFS1302) was grown in four different media: ISO-Sensitest broth (ISB), E. coli broth (ECB), trypticase soy broth (TSB), and Mueller Hinton broth (MHB), with or without mitomycin C at 37°C (250 rpm) for 6 h. Toxin production was measured by enzyme-linked immunosorbent assay. In the presence of mitomycin C, ECB was found to be the most suitable medium, reaching a production peak (OD600 = 1.2) at 1 h; Stx2e was mostly produced during the logarithmic phase (within 3 h). On the other hand, toxin production in ISB reached a peak at 3 h after incubation in the absence of mitomycin C. Stx2e was purified by fast protein liquid chromatography (FPLC) using anion-exchange chromatography. The 43 kDa band of Stx2e was confirmed by western blot using the ECB supernatant. Our results showed that ECB and ISB media would be a suitable medium for mass production of Stx2e even if the toxin production is dependent on time.

The emergence of antimicrobial resistant Escherichia (E.) coli is a major problem in pig farms. To tackle this issue, in July 2011, the Korean government banned the use of antimicrobials for growth promotion of animals in farms. Moreover, E. coli encoding the Stx2e gene cause edema disease which results in high mortality and morbidity in pig farms. Therefore, the aim of this study was to investigate the prevalence of antimicrobial resistance among E. coli encoding the Stx2e gene isolated from weaned piglets with diarrhea before and after the ban on antibiotic growth promoters (AGPs) in Korea from 2007 to 2016. In this period, 479 E. coli isolates were obtained from weaned piglets with diarrhea, and of them, 144 E. coli isolates encoding the Stx2e gene were detected by polymerase chain reaction. The susceptibility of the E. coli isolates to antibiotics were tested using the standard Kirby-Bauer disk diffusion method. The most frequently observed resistances in isolates obtained from weaned piglets in the last 10 years were to tetracycline (92.4%) and chloramphenicol (88.9%). The prevalence of resistance to colistin (3.1% to 16.5%) and tetracycline (86.2% to 97.5%) was also observed to have increased over this period. Additionally, multi-drug resistance was also found to have increased (87.7% to 97.5%) after the ban on AGPs. These findings provide useful data for designing prevention and treatment strategies for postweaning diarrhea and edema disease, and can be used in future studies on antimicrobial resistance in Korea.

The female azuki bean beetle, Callosobruchus chinensis L., a worldwide notorious pest of azuki beans produces sex pheromone having two isomer compounds; (2Z,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals (2Z-homofarnesal) and (2E,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals (2E-homofarnesal). We synthesized and evaluated the attractiveness of different blends of the two isomeric compounds using Y-olfactometry in laboratory and rocket traps in the field. The attractiveness pattern of the tested blends in Y-olfactometry was found as 1:9≥6:4>9:1 of 2E-:2Z-homofarnesal. Under field condition also, the 6:4 blend was more attractive than 9:1 blend. The result ascertained the enhanced pheromonal activity of homofarnesal with the increased ratio of Z-component in the blend. This provides an opportunity to synthesize Z-rich homofarnresal with less sophisticated and economically feasible Z-selective method.

A most important progress in civilization was the introduction of mass production. One of main methods for mass production is die-casting molds. Due to the high velocity of the liquid metal, aluminum die-casting is so complex where flow momentum is critical matter in the mold filling process. Actually in complex parts, it is almost impossible to calculate the exact mold filling performance with using experimental knowledge. To manufacture the lightweight automobile bodies, aluminum die-castings play a definitive role in the automotive part industry. Due to this condition in the design procedure, the simulation is becoming more important. Simulation can make a casting system optimal and also elevate the casting quality with less experiment. The most advantage of using simulation programs is the time and cost saving of the casting layout design. For a die casting mold, generally, the casting layout design should be considered based on the relation among injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimize the casting layout design of an automotive Oil Pan_BR2E, Computer Aided Engineering (CAE) simulation was performed with three layout designs by using the simulation software (AnyCasting). The simulation results were analyzed and compared carefully in order to apply them into the production die-casting mold. During the filling process with three models, internal porosities caused by air entrapments were predicted and also compared with the modification of the gate system and overflows. With the solidification analysis, internal porosities occurring during the solidification process were predicted and also compared with the modified gate system.

For a die casting mold, generally, the casting layout design should be considered based on the relation among injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimize the casting layout design of an automotive Oil Pan_DX2E, Computer Aided Engineering (CAE) simulation was performed with two layout designs by using the simulation software (AnyCasting). The simulation results were analyzed and compared carefully in order to apply them into the production die-casting mold. During the filling process with two models, internal porosities caused by air entrapments were predicted and also compared with the modification of the gate system and overflow. With the solidification analysis, internal porosities occurring during the solidification process were predicted and also compared with the modified gate system.

Matrix 2 protein ectodomain (M2e) of influenza virus appears to be a promising vaccine candidate because its sequence is highly conserved among virus strains. However, M2e is too meager to induce a strong immune response by itself. Several approaches are being used to increase the antigenicity of M2e. In an effort to enhance the M2e-specific immune response, we generated a TAT-conjugated M2e recombinant protein. Seven-week-old BALB/c mice were divided into three groups and transcutaneously immunized with 100 μg TAT-8×M2e (TAT conjugated with eight copies of M2e) and 8×M2e (eight copies of M2e) proteins on days 1, 15 and 29. The control mice were injected with PBS on the same days. Antibody titers specific for M2e were measured using indirect ELISA. Mice immunized with the TAT-8×M2e and 8×M2e proteins developed almost the same levels of M2e-specific total IgG and IgG1 antibodies. However, a higher level of M2e-specific IgG2a was observed in mice immunized with TAT-8×M2e than in those immunized with 8×M2e. These results suggest that TAT has an adjuvant effect that induces a Th1-type immune response. Therefore, the TAT-M2e vaccine can be applied to animals as a new influenza vaccine for enhancement of Th1-type immune responses.

When manufacturing die casting mold, generally, the casting layout design should be considered based on the relation among injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimizing casting layout design of an automobile part (Oil Pan_DX2E) Computer Aided Engineering (CAE) simulation was performed with two layout designs by using the simulation software (AnyCasting). The simulation results were analyzed and compared carefully in order to apply them into the production die-casting mold. During the mold filling with two models, internal porosities caused by air entrap were predicted and also compared by the modification of the gate system and the configuration of overflow. With the solidification analysis, internal porosities caused by the solidification shrinkage were predicted and also compared by the modification of the gate system.

When manufacturing die casting mold, generally, the casting layout design should be considered based on the relation among injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimizing casting layout design of an automobile part (Oil Pan_DX2E) Computer Aided Engineering (CAE) simulation was performed with two layout designs by using the simulation software (AnyCasting). The simulation results were analyzed and compared carefully in order to apply them into the production die-casting mold. During the mold filling with two models, internal porosities caused by air entrap were predicted and also compared by the modification of the gate system and the configuration of overflow. With the solidification analysis, internal porosities caused by the solidification shrinkage were predicted and also compared by the modification of the gate system.

수질모델은 수계내 오염물질의 총량관리를 위한 오염물질관리 목표량 및 허용총량 파악, 그리고 삭감계획의 효과분석 등에 효율적으로 사용할 수 있다. 그러나 선정 또는 개발된 모델의 재현성 제고를 위하여 매개변수의 최적화작업이 필요하다. 본 연구에서는 하천수질관리에 가장 광범위하게 사용되고 있는 미국 EPA에서 개발한 QUAL2E 모델의 반응계수 보정을 위하여 최소자승법을 적용하였으며, 계수가 취할 수 있는 범위를 제약조건으로 갖는 최적화모델을 구축하여 해를

The Keum river is one of the important river in Korea and has a drainage area of 9,873 ㎦. The Keum river is deepening pollution state due to development of the lower city and construction of a industrial complex. The water quality of the Keum river come to eutrophication state and belong to Ⅲ grade of water quality standard. The concentration BOD in river is affected by the organic loading from a tributary and the algae biomass that largely happen to under eutrophication state. In the eutrophic water mass such as the Keum river, the autochthonous BOD was very important part for making a decision of water quality management, because it was accounted for majority of the total BOD. The purpose of this study was to survey the characteristics of water quality in summer and to estimate reaction coefficient. Also, we studied to correlationship between chlorophyll a and BOD(COD) for estimation of the autochthonous BOD. The correlationship between chlorophyll a and BOD(COD) were obtained through the culture experiment of phytoplankton in the laboratory. The results of this study may be summarized as follows ; The characteristics of water quality in summer were belong to Ⅲ∼Ⅳgrade of water quality standard as BOD and nutritive condition is very high. The BOD, ammonia nitrogen and phosphate loadings in Miho stream which inflowing untreated sewage from Chungju city was occupied with 64.07%, 26.36%, 46.08%, respectively. Maximum nutrient uptake (Vmax) was 0.4400 μM/hr as substrate of ammonia nitrogen, 0.1652 μM/hr as substrate of phosphate. Maximum specific growth rate (μmax) was 1.2525 hr-1 as substrate of ammonia nitrogen, 1.5177 hr-1 as substrate of phosphate. The correlation coefficient between chlorophyll a and BOD by the culture experiment were found to be 0.911∼0.935 and 0.942∼0.947 in the case adding nutrient and no adding nutrient, respectively. The correlation coefficient between chlorophyll a and COD through the culture experiment were found to be 0.918∼0.977 and 0.880∼0.931 in the case adding nutrient and no adding nutrient, respectively. The autochthonous BOD(COD) was estimated to the relationship between BOD(COD) and chlorophyll a. The regression equation were found to be autochthonous BOD=(0.045∼0.073)×chlorophyll a and autochthonous COD=(0.137∼0.182)×chlorophyll a.

The Keum river has been utilized for drinking water supply of several city including Kunsan city and is deepening pollution state due to numerous municipal and industrial discharges. The concentration BOD in river is affected by the organic loading from a tributary and the algae biomass that largely happen to under eutrophication state. In the eutrophic water mass such as the Keum river, the autochthonous BOD was very important part for making a decision of water quality management, because it was accounted for majority of the total BOD. The predict of water quality has important meaning for management of water quality pollution of the Keum river. The purpose of this study will manage and predict water quality of the Keum river using QUAL-2E model considering the autochthonous BOD. The estimation of autochthonous BOD represented that the relationship between BOD and chlorophyll a. The regression equation was shown to be autochthonous BOD=β5×chlorophyll a. The results of this study may be summarized as followed; The QUAL-2E model was calibrated with the data surveyed in the field of the study area in June, 1998. The calculated value by QUAL-2E model are in good agree to measured value within relative error of 7.80∼20.33%. Especially, in the case of the considering autochthonous BOD, the calculated value of BOD were fairly good coincided with the observed values within relative error of 15%. But the case of not considering autochthonous BOD, relative error of BOD was shown to be 43.2%. In order to attain Ⅱ grade of water quality standard in Puyo station which has a intake facility of water supply, we reduced to the pollutants loading of tributaries. In the case of removed 100% BOD of tributaries, the BOD of Puyo station was 4.07㎎/ℓ, belong to Ⅲ grade of water quality standard. But in the case of removed 88% nutrient of tributaries, it was satisfied to Ⅱ grade of water quality standard as below 3㎎/ℓof BOD. For estimation of autochthonous BOD in Keum river, we are performed simulating in accordance with reduction of nutrient load(50∼100%) under conditions removal 90% organic load. Occupancy of autochthonous BOD according to nutrient loading reductions were varied from 25.97∼79.51%. Occupancy of autochthonous BOD was shown to be a tendency to increasing in accordance with reduction of nutrient loading. Showing the above results, the nutrient that one of the growing factor of algae was important role in decision of BOD in the Keum river. For the water quality management of the Keum river, therefore, it is necessary to considering autochthonous BOD and to construction of advanced sewage treatment plant for nutrient removal.