This paper systematically analyzed research trends of North Korean defectors’ English education in South Korea using the scoping literature review method. From 2001 to 2022, research on this topic was categorized into three phases: 1) Phase 1 (2000-2011), 2) Phase 2 (2012-2019), and 3) Phase 3 (2020-Present). Each phase was analyzed using school levels, themes, and research methods. Approximately a quarter of previous research investigated alternative schools for North Korean defectors, with students having difficulties with their limited English learning experiences. Research themes mainly concentrated on learner factors (48 papers), followed by educational contexts and teaching methods (21 papers). Most studies on appropriate teaching methods for North Korean defectors adopted qualitative methods focusing on a small number of participants. Regarding research methods, studies adopting qualitative methods accounted for 48.0%, whereas studies using quantitative ones accounted for 10.4%, reflecting the limited research opportunities to collect a large set of data from various North Korean participants in South Korea.

Bongsu(Beacon Fire Station) is a facility that sends signals with fire and smoke and has been used in Korea since the Three Kingdoms period. This facility was installed to know the north and south crises. This trend continues until the Joseon Dynasty, and it has been somewhat completed in the 17th century. In previous studies, beacon fire was identified mainly from the border area to Hanyang. Based on this, it was classified into Gyeongbongsu, Yeonbyeonbongsu, and Naejibongsu. However, it is difficult to define the characteristics of beacon fire in coastal areas only with this classification. In the case of beacon fire in island areas, there was a tendency to value communication connection within the region rather than connection with the capital. As a case analysis for this, an academic review was conducted with the cases of Ganghwa Island and Jeju Island. As a result, it was confirmed that the role and character of the beacon vary depending on the defense system and the physical distance from the land, even if it has the topographical commonality of the same island.

This paper investigates Korean EFL students’ learning (de)motivation factors according to the level of students’ English learning motivation. A total of 41 undergraduate students reflected on their past ten years of English learning experiences and submitted autobiographic essays with ‘motigraph,’ marking their annual changes of English learning motivation from 0 to 10. The data were analyzed with Grounded Theory. The findings revealed that the factors that increased or decreased English learning motivation were different according to students’ level of motivation. Students with low-level motivation were influenced by their teacher or parents, while those with high-level motivation were influenced by their past L2 learning experiences perceived positively by themselves. In both groups, the factors of emotional experiences caused by negative L2 learning experiences were the main reasons for demotivation. This paper emphasizes the importance of subjective appraisal in maintaining students’ L2 learning motivation and recovering from the state of demotivation.

This study investigates the historical development of English education in South Korea regarding the fourth and fifth National Curriculum Period. By analyzing the newspaper articles in five major newspapers in Korea, we focused on the characteristics of English education in each period. The research questions are: 1) what are the characteristics of the fourth National Curriculum? 2) what are the characteristics of the fifth National Curriculum?, and 3) what is the implication of these previous curricula on the current English education in South Korea? During the fourth National Curriculum Period, after the successful hosting of the 1986 Asian Games and the 1988 Summer Olympic Games in Seoul, the importance of communication skills in English spread throughout the country. Accordingly, the need for early English education emerged. In the fifth curriculum, various social factors, including the liberalization of overseas travel, led positive washback effects on English education. In elementary schools, English instructions were conducted as a special activity. In secondary schools, various changes in the educational environment were involved, including the introduction of listening tests and recruitment of native English teachers, which still affects English education in 2020. This paper concludes with educational implications and future research directions.

This paper explores the historical development of English education in Korea regarding the second and third National Curriculum period. By using the historical research method which analyzes newspaper articles in four major newspapers in Korea, we compared the similarities and differences between these two periods. The research questions are: 1) what are the characteristics of the second National Curriculum? 2) what are the characteristics of the third National Curriculum?, and 3) what is the implication of these previous curricula on the current English education in Korea? It was found that the second National Curriculum Period showed steady development in English education in terms of its emphasis on oral skills instead of the traditional emphasis on reading and grammar skills. However, the lack of coherence among various English textbooks, the lack of English teachers fluent in English, and the exam-oriented social atmosphere were the significant challenges in fully implementing the second National Curriculum. The third National Curriculum Period overlaps with the Yushin Regime propagated by the late President Park Junghee. During this period, a systematic effort to introduce communicative language teaching continued, whereas the exam-orientation persisted which made the English class employ teacher-centered grammar-translation methods. This paper concludes with educational suggestions and future research directions.

In this study safety distance was investigated for small-scale LNG storage facilities in order to provide basic data for safety. The results are as follows; (1) For explosion pressure criteria, current criteria are reasonable, but water spray system should be recommended to LNG storage tank to ensure safety. (2) For criteria based on the results of the quantitative risk assessment, criteria applied to people are 5kW/㎡ for radiation, LFL for dispersion, and 7kPa for explosion pressure. And criteria applied to facility are 37.5 kW/㎡ for radiation and 20 kPa for explosion pressure.

This study was conducted to investigate the effects of different levels of soybean curd residue as an ingredient of TMR on growth performance and carcass characteristics of Holstein steers. Twenty four Holstein steers of 7 months age(average body weight 274.6 kg) were randomly allocated to 3 experimental groups, which contained 8animals per group during 15-months feeding trial. The treatments composed of the group fed concentrate and rice straw separately (Control), the group fed TMR containing low levels of soybean curd (T1), the group fed TMR containing high levels of soybean curd residue (T2). Body weight and average daily gain were not significantly different among the treatment groups during the feeding trial periods. Feed intake was not differ among treatment groups, but feed conversion ratio was significantly higher in T2 group compared to T1 group during late fattening stage (p<0.05). However, it was not different in overall average. According to the yield traits, carcass weight of control, T1 and T2 were 466.4, 451.1 and 460.1 kg, respectively. Back fat thickness, rib eye area and yield index were not different among the groups. The marbling score, meat color, texture and maturity in quality traits were not different among the treatment groups, but fat color was significantly higher in T2 group compared to T1 group (p<0.05). The quality grade (1+:1:2:3, NO.) tended to be higher for T1(0:2:1:5) and T2 (0:1:4:3) compared with the control (0:0:3:5). Therefore, these results indicated that TMR with soybean curd residue may be appropriate the growth performance and carcass characteristics of Holstein steers.

Cryopreservation induces sublethal damage to the spermatozoa, which leads to their reduced fertile life. This study was designed to determine effect of glycerol and ethylene glycol as cryoprotectant in extender on improve the freezability of Jeju horse semen. The semen was cryopreserved with glucose-EDTA extender containing each 5% glycerol, 5% ethylene glycol, 8% glycerol or 8% ethylene glycol, respectively. Post-thawed sperm were evaluated motility, viability, Membrane integrity and acrosome integrity. Post-thawed sperm motility were not significantly differences among treatments. However, sperm viability were significantly higher (p<0.05) in 8% glycerol (39.85% ±11.41) than in 5% glycerol treatment (18.08%±1.61). In membrane integrity, swelling sperm ratio was significantly higher (p<0.05) in 8% glycerol (34.12%±11.02) than other treatments. In the percentage of capacitated sperm assessed by CTC staining, F pattern was significantly higher in 8% ethylene glycol than 5% glycerol and 5% ethylene glycol (p<0.05). B pattern ratio was significantly increased in 5% ethylene glycol compared with 8% glcerol and 8% ethylene glycol (p<0.05). Moreover, 8% ethylene glycol treatment was significantly decreased AR pattern ratio compared with other treatments (p<0.05). It is concluded that treatment of 8% glycerol was improved the sperm viability and 8% ethylene glycol was improved the sperm ascrosome integrity after thawing. However, they were not significantly difference between 8% glycerol and 8% ethylene glycol on post-thawed sperm viability. Therefore, 8% ethylene glycol was more effective sperm cryoprotectant than 8% glycerol in Jeju Horse.

This study was designed to determine whether low-density lipoporoteins (LDL) extracted from egg yolk in extender improve the function of Korean Jeju Black Bull semen. The semen was cryopreserved with 5% ethylene glycol (EG) or 7% glycerol (G) extenders containing 10% egg yolk (EY), 4% LDL and 5% EY or 8% LDL. Frozen-thawed sperm were evaluated sperm motility, viability, membrane integrity and acrosome integrity. Post-thawed sperm motility has been significantly higher (p<0.05) in 4% LDL + 5% EY (; EG and ; 7% G) than 8% LDL (; EG and ;G). Treatment of 4% LDL + 5% EY-EG () has been significantly improved sperm viability compared to other treatments except 10% EY - EG. Moreover, in membrane integrity, swollen sperm ratio has been only significantly increased (p<0.05) in 4% LDL + 5% EY - EG () among all treatments. In assess to detect acrosome integrity, especially, AR pattern ratio has been significantly decreased (p<0.05) in 4% LDL + 5% EY - EG among all treatments. In sperm viability as time passes, between 4% LDL + 5% EY and 10% EY, there was no significant difference, but 8% LDL was significantly decreased sperm viability in EG (1 and 2 hrs) and G (30 min, 1, 2, 5 and 12 hrs) extender. However, there were no significant differences among all treatments except 8% LDL-G in sperm membrane integrity. 8% LDL-G has been significantly decreased swollen sperm ratio at 5 hrs after thawed. It is concluded from these results that 4% LDL + 5% EY to the freezing extender showed more positive effect on the frozen-thawed spermatozoa in Korean Jeju Black bull.

This study was designed to determine whether low-density lipoproteins (LDL) from egg yolk and taurine, hypotaurine and trehalose as antioxidant in extender improve the freezability and fertility of Korean Jeju Black Bull semen. The semen was cryopreserved with tris egg yolk extenders containing 7% glycerol and treated 4% LDL, 20 mM taurine, hypotaurine and trehalose. Frozen-thawed sperm were evaluated motility, viability, membrane, and acrosome integrity and sperm penetration ability. The results were compared to semen cryopreserved in tris egg yolk extender only as control. Frozen-thawed semen evaluation cleary indicated that the addition of LDL and LDL-antioxidants (taurine, hypotaurine and trehalose) combination were significantly improved (p<0.05) the viability (%; with staining test using eosin-Y) compared to control spermatozoa. Also, in membrane integrity (%; with supravital hypo-osmotic swelling test), not only LDL-antioxiants combination but also LDL were significantly increased (p<0.05) the swelled sperm using HOST compared to control. Sperm acrosome integrity state was classified by CTC (chlortetracycline) staining test. F pattern was significantly increased in LDL-antioxidant combination than control (p<0.05) and B pattern was not significantly differences among all treatments and control. However, AR pattern was significantly decreased in LDL-antioxidants combination than control (p<0.05). Pronucleus formation and sperm penetration index (SFI) were significantly increased in LDL and LDL-antioxidants combination than control (p<0.05). Especially, LDL-taurine significantly improved pronucleus fomation and SFI than LDL (p<0.05). It was concluded that LDL and LDL-antioxidants in extender improved the freezability and fertility of Korean Jeju Black bull spermatozoa.

The objective of this study was to examine effect of ethylene glycol for semen cryopreservation in Korean Jeju Black Bull. The semen was cryopreserved with extenders containing cryoprotectants (7% glycerol and 3%, 5%, 7% ethylene glycol) and packed to 0.5 ml straws. The semen straws were located above 3 cm of liquid nitrogen for 5 min, 5 cm for 10 min and 8 cm for 10 min. And then frozen straw was plunged into LN2. Post-thawed sperm motility, viability and membrane integrity were significantly higher in 5% ethylene glycol (72.5±5.00%, 54.88±0.66% and 46.00±2.40%; p<0.05). Motility and viability were similar between 7% glycerol and 5% ethylene glycol. However, the membrane integrity was significantly higher in 5% ethylene glycol (34.69±4.64% vs 46.00±2.40%; p<0.05). The viability and membrane integrity were significantly higher in 5 cm for 10 min and 8 cm for 10 min than 3 cm for 5 min (viability: 55.81±2.94, 55.19±3.34 vs 47.94±3.48%; p<0.05 and membrane integrity: 44.94±3.51, 46.06±2.25 vs 40.38±1.03%; p<0.05). The percentage of capacitated sperm assessed by CTC staining, percentage of F pattern was higher in 7% glycerol, 5% and 7% ethylene glycol, and AR pattern was significantly higher in 3% ethylene glycol. F pattern was significantly increased in 5 cm for 10 min and 8 cm for 10 min (p<0.05), but AR pattern was significantly increased in 3 cm for 5 min (p<0.05).

This study was carried out to establish most suitable freezing condition, to evaluate the different glycerol concentration of freezing and thawing rates on motility, viability, membrane integrity and acrosome intecrity of frozen Korean Jeju Black Bull spermatozoa, Semen was collected from a Korean Jeju Black Bull using an artificial vagina and transported to the laboratory. The semen was extended gradually 1:5 then cooled slowly for 2 hrs to 4. The semen was diluted 1:1 with cryoprotectant extenders (3%, 5% and 7% glycerol) and equilibrated for 2 hrs at cold chamber and packed to 0.5 ml straws. The semen straws were located above 3 cm of liquid nitrogen for 5 minutes, above 5 cm for 10 min and above 8 cm for 10 min. And then the frozen straw was plunged into LN. The presented straws were examined the viability and motility after thawed at 37 water bath. The viability and membrane integrity immediately post-thawing were significantly higher in samples frozen in 7% glycerol than 3% and 5% glycerol (p<0.05). After CTC staining to assess acrosome integrity, F pattern was significantly increased, but B pattern was significantly decreased in 7% glycerol (p<0.05). Freezing distance of 5 cm from liquid nitrogen and pre-cooling for 10 min yield better survival and membrane integrity, but not significant difference. However, AR pattern according to CTC staining was significantly decreased in 3 cm for 5 min.

Endocrine disruptors bind to hormone receptors on sperm membrane, therefore spermatozoa are potentially a useful model for examining estrogenic activities of endocrine disruptors. The objective of this study was to compare the effects of two xenoestrogenic compounds [genistein (Gen) and 4-tert-octylphenol (OP)] to those of two steroids [estrogen (E2) and progesterone (P4)] on boar sperm % motility and motion kinematics of in vitro. Porcine spermatozoa were incubated with various concentrations (0.001～100 μM) of each chemical for 15 or 30 min, and then assessed % motility and sperm motion kinematics using computer assisted sperm analyzer (CASA). Each chemical decreased sperm % motility, and OP decreased VSL and VAP compared with untreated control(p<0.05). E2 stimulated the motion kinematic changes except VCL. Moreover, Gen had effects on VCL and VAP alterations after 30 min incubation. In summary, since all chemicals studied effectively altered sperm % motility and motion kinematics, it was concluded that porcine spermatozoa could be a useful model for in vitro screening of potential endocrine disruptors.

본 연구는 정액의 보존 기간 동안 정액의 질적 변화를 알아보고자 시행하였다. 돼지 정액을 Beltsville Thawing Solution (BTS)에 희석한 후 17'C 에서 5일 동안 보존하였다. 보존 기간 동안 정자의 운동성(%)과 linearity는 3일째부터 유의하게 감소하였으나, 다른 운동 역학 변수에서는 유의적 변화를 나타내지 않았다. 또한, 5일 동안 정액을 보존할 경우 첨체의 온전성에도 변화가 없었다. 그러나 제 4일째부터 첨체 변화가 야기된 정자는 유의적으로 증가하였으나, 수정능 획득이 일어난 정자는 유의적으로 감소하였다. 정액의 보존 기간 동안 첨체의 온전성의 유의적 변화가 없었다. 즉, 보존 기간 3일동안 정자의 질적 운동성 및 첨체 온전성에는 유의적인 변화가 없었으므로 상업용 돼지 액상정액은 17'C 에서 적어도 3일간 수정능력을 만족스럽게 유지함을 보여준다.

본 연구는 정자 내의 phsopholipid hydroxide glutathion peroxidase (PHGPx) mRNA 발현 수준, heparin-binding protein (HBP) mRNA 발현 수준, 수태율 그리고 산자수 사이의 관계를 조사하고자 실시하였다. 수태율과 산자수 사이에 있어서 상관관계는 나타나지 않았다. PHGPx mRNA 발현 수준에 있어 산자수가 10두 이상 군에서 (2,414.7±400.7) 8두 미만 군보다 (1,875.8±311.2) 높게 나타났으나 유의적인 차이는 없었다. HBP mRNA 발현 수준에 있어서도 산자수 10두 이상 군에서 (2,255.9±360.8) 8두 미만 군보다 (2,155.4±378.0) 약간 높은 결과를 보였으나, 유의적인 차이는 인정되지 않았다. PHGPx mRNA 발현 수준과 산자수 사이의 관계는 (r=0.206) 정의 상관관계를 보였으나, 유의한 상관관계는 나타나지 않았다. 본 실험의 결과, PHGPx와 HBP의 발현수준이 수태율, 산자수와 유의한 상관관계를 보이지 않았기 때문에 PHGPx와 HBP가 정자의 수정능력을 예측하기에는 미흡한 면이 있다.

목 적 : ORB-ScanII (Version 3 .1 2) 와 DGH500 Ultrasonic pachymetry를 이용하 여 시력교정수술 전 각막중심두께를 측정하여 비교함으로써 수술의 안정성과 정확성 을 높이고자 하였다. 대상과 방법 : 본원에 시력교정수술을 받기 위해 내원한 환자 66 명 130안을 대상 으로 각막두께를 측정하였다. ORB-ScanII 은 어두운 조명에서 3 회를 측정하였고 DGH500 Ultrasonic pachymetry는 20 회 이상 측정하여 중심부의 가장 앓은 각막의 두께를 사용하였다. 두 측정장치의 평균과 표준편차를 알아보았고 일치성은 상관분석 과 회귀분석을 통해 알아보았다. 결 과 : 평균 각막중심두께는 ORB-Scan II z로 측정한 경우는 529 .45 :t 33.34μm 이 였고， DGH500 Ultrasonic pachymetry로 측정한 경우는 525.22 :t 3 1.21μm 이였으며， ORB-ScanII 이 DGH500 Ultrasonic pachymetry보다 평균 4.23 :t 7.91 따l 더 높게 측정 되었다. ORB-ScanII 와 DGH500 Ultrasonic pachymetry 의 상관계수는 0.972로 1 에 가까웠 으며 선형회귀분석을 통하여 회귀식을 구하였다. 결 론 : 두 기기로 측정한 값에서 가장 앓은 각막두께를 기준으로 함으로써 수술 의 안정성을 높였으며 수술 후에 발생할 수도 있는 각막 변형을 예방하는데 도움을 주였다. 하지만， 측정 방식에 따른 측정 장치의 오차를 줄일 수 있는 기술적 발전이 펼요하리라 생각된다.

Cost-benefit analysis was investigated to propose the analysis method of the effect of investment and the optimum investment level of safety management cost for preventing gas accident in the B governor station. From five classifications of safety management costs consisting of cost items with similar characters and potential accident costs calculated by risk assessments(FMEA/HAZOP), we found that the order of the benefit(the reduction cost of the potential accident cost) was the instrument increase and repair cost > the safety checking and inspection cost > the labor and training cost > the safety equipment and corresponding cost > the research and development cost. As the benefit was increased with increasing the investment cost, the effect of investment was increased with decreasing the Investment cost. As a result, the optimum safety management cost was estimated and the investment level was analyzed by the model of optimum investment level.