• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.554-561
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• 2022

Technology development related to maritime autonomous surface ships (MASS) is actively progressing around the world. However, since there are still many technically unresolved problems such as communication, cybersecurity, and emergency response capabilities, it is expected that it will take a lot of time for MASS to be commercialized. In this study, we proposed a ship group navigation system in which one leader ship and several follower ship are grouped into one group. In this system, when the leader ship begins to navigate, the follower ship autonomously follows the path of the leader ship. For path following, PD (proportional-derivative) control is applied. In addition, each ship navigates in a straight line shape while maintaining a safe distance to prevent collisions. Speed control was implemented to maintain a safe distance between ships. Simulations were performed to verify the ship group navigation system. The ship used in the simulation is the L-7 model of KVLCC2, which has related data disclosed. And the MMG (Maneuvering Modeling Group) standard method proposed by the Japan Society of Naval Architects and Ocean Engineering (JASNAOE) was used as a model of ship maneuvering motion. As a result of the simulation, the leader ship navigated along a predetermined route, and the follower ship navigated along the leader ship's path. During the simulation, it was found that the three ships maintained a straight line shape and a safe distance between them. The ship group navigation system is expected to be used as a navigation system to solve the problems of MASS.

• Education of Primary School Mathematics
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• v.25 no.2
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• pp.179-195
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• 2022

Mathematical communication competency, one of the six mathematical competencies emphasized in the latest mathematics curriculum, plays an important role both as a means and as a goal for students to learn mathematics. Therefore, it is meaningful to find instructional methods to improve students' mathematical communication competency and analyze their communication competency in detail. Given this background, this study analyzed 64 sixth graders' mathematical communication competency after they participated in the lessons of fraction division emphasizing mathematical communication. A written assessment for this study was developed with a focus on the four sub-elements of mathematical communication (i.e., understanding mathematical representations, developing and transforming mathematical representations, representing one's ideas, and understanding others' ideas). The results of this study showed that students could understand and represent the principle of fraction division in various mathematical representations. The students were more proficient in representing their ideas with mathematical expressions and solving them than doing with visual models. They could use appropriate mathematical terms and symbols in representing their ideas and understanding others' ideas. This paper closes with some implications on how to foster students' mathematical communication competency while teaching elementary mathematics.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.60-66
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• 2023

Currently, the maritime industry is focusing on developing technologies that promote autonomy and intelligence, such as smart ships, autonomous ships, and eco-friendly technologies, to enhance ship operational efficiency. Many countries are conducting research on different methods to ensure ship safety while increasing operational efficiency. This study aims to develop a real-time ship operational efficiency analysis model using data analysis methods to address the current limitations of the present technologies in the real-time evaluation of operational efficiency. The model selected ship operational efficiency factors and ship operational condition factors to compare the operational efficiency of the ship with present and classified factors to determine whether the present ship operational efficiency is appropriate. The study involved selecting a target ship, collecting data, preprocessing data, and developing classification models. The results of the research were obtained by determining the improved ship operational efficiency based on the ship operational condition factors to support ship operators.

• Journal of Food Hygiene and Safety
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• v.4 no.2
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• pp.119-132
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• 1989

Gamma irradiation as a new physical treatment was applied to comparative investigates with a conventional ethylene oxide fumigant on the microbiological and physicochemical qualities of selected spices and dry vegetables such as powdered red pepper, black pepper, welsh onion, onion, garlic, carrot, korean cabbage and instant ramyon soup. The microorganisms contaminated in the sample, including total viable count, thermophilic bacteria, aerobic spore and fungi counts between the $10^4\;to\;10^6/g$ range. Coliforms were found only in black pepper and welsh onion powder as the $10^2\;to\;10^3/g$ level. A radiation dose of 7 to 10 KGy were sterilized completely to the contaminated microorganisms, while ehthylene oxide (E.O.) fumigation reduced of them to the $10^3/g$ level. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples. Comparison gamma irradiation with E.O. gas treatment showed that E.O. treatment was less effective than radiation in cotrolling microbial contamination of spices and vegetables.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.279-286
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• 2009

An experiment was conducted to investigate the effects of dietary supplementation of cerium (Ce), a rare earth, individually and in combination with lanthanium (La), a rare earth, in the basal diet on growth performance, nutrient digestibility, bone composition, breast meat composition, carcass characteristics and meat color in broiler chicks. A total of 1,600 day-old broiler chicks were randomly allotted to four dietary treatments with four replicates in a completely randomized block design. Treatments were T1) CON (control diet), T2) 100 ppm Ce, T3) 100 ppm La, T4) 100 ppm Ce+100 ppm La. There were no significant differences in feed intake among dietary treatments during the whole experimental period (0 to 5 weeks). Body weight gain for the first three weeks was greater in birds T4 than birds fed T3 diet. Feed conversion ratio (FCR) was better in birds fed T4 diet (p<0.05) than birds fed T3 diet during 0~3 weeks, and better FCR for 0~5 weeks was noticed in birds fed T4 diet than birds fed T1 diet. Nutrient digestibility was greatest in birds fed T3 diet (p<0.05) compared with other treatments. Bone composition, carcass characteristics and meat color were no statistically different among the treatments. These results suggest that Ce supplementation, alone and combination with La could improve performance of broilers.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.6 no.1
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• pp.74-89
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• 1995

Selective mutism is a childhood condition defined by persisten failure to speak in specific social situation when speaking is expected, dispite preserved ability to comprehend spoken language and speak. Present study is to investigate clinical characteristics, treatment method and outcome of 23 children who were diagnosed as selective mutism by DSM-IV criteria at the child psychiatry ouptatient department of SNUH. The results were as follows : 1) The Sex ratio was 1: 4.8, female dominant Mear age of onset was 33 years old and mean age of first referral was 7.7 years old. 2) 22% of subjects had perinatal problem such as low birth weight, preterm birth, 26% of the subjects have history of delayed language development. There are subjects who had been separated with mam caretaker before 3 years old(26%) and who experienced physical or psychological trauma before 3 years old(26%). A few subjects had enurests(30%) and encoprests(4%). 3) Many subjects(65%) had symbiotic relationship with their mother. These families consist of dominant, verbally aggressive mother and passive father. Parents of 39% of all subjects were judged to have definite psychopathology(social phobic, depression, hysterical trait or alcohol problem) 26% of all subject, were reported physically abused. 4) The personality trait of the subjects were frequently described as follows(in order of frequency) ; Shy(100%), anxious(83%), stubborn(83%)m rigid and tense posture(78%), immature(65%) overdependent(65%), irritable(52%), manipulative(39%), depressive(39%). 5) The mean performance IQ of 16 subjects by KEDI-WISC was 88.3 Among them, the subjects with IQ below 69 were seven and those with IQ above 70 were nine. When comparing these two group(Mental retardation group vs Normal IQ group), we could find some difference in language development, personality trait, family dynamics and treatment outcome. 6) Among several treatment methods for selective mutism, play therapy was the most frequently used method(65%). Other commonly used treatment methods were pharmacotherapy(21%), behavioral therapy(8%), combined therapy(play therapy+pharmacotherapy+family therapy+behavioral therapy)(12%), 7) Regarding the outcome of treatment 8.6% was evaluated as Excellent, 30.4% as Good, 52% as Fair, 8.7% as Poor at the tinic of treatment. At follow up interview 21.7% was evaluated Excellent, 13% as Good, 21.7% as Fair, 34.8% as Poor. 8) We classified all subjects by Havden's 4 subtype. Symbiotic mutism was most common(65%) and other subtypes are Speech phobic mutism(8.6), Reactive mutism(13%) and Passive-aggressive mutism(30%).

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.1-8
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• 2010

An experiment was conducted to investigate the effect of dietary supplementation of rare earth, individually and in combination with colloidal silver on growth performance, nutrient digestibility, carcass characteristics and immune response in broiler chicks. A total of 3,872 day-old chicks were randomly allotted to four dietary treatments in a randomized complete block design. There were four pens per treatment and 242 chicks per pen. The dietary treatments were T1) CON (control diet), T2) colloidal silver (control diet+20 ppb colloidal silver), T3) rare earth elements (control diet+500 ppm rare earth), T4) colloidal silver +rare earth elements (control diet+20 ppb colloidal silver+500 ppm rare earth). There were no significant differences in feed intake and feed conversion ratio (FCR) among dietary treatments during the whole experimental period (0 to 5 weeks). Body weight gain was greatest in birds fed T3 and T4 diets (p<0.01). Apparent digestibility of dry matter, crude protein, ether extract and calcium were greatest in birds fed T4 diet (p<0.05), while apparent digestibility of phosphorus was lowest in birds fed T3 diet (p<0.05). There was no significant difference in bone strength, carcass characteristics and immune response among dietary treatments. Dry matter content of bone was greatest in birds fed T4 diet (p<0.05), and phosphorus content of bone was greater in birds fed T3 diet than in birds fed T2 and T4 diets (p<0.05). Thus, the results of this study suggest that rare earth elements supplementation, individually and in combination with colloidal silver could improve performance of broilers.

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.253-258
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• 2004

Purpose: Chitosan has been studied as a non-viral gene delivery vector, drug delivery carrier, metal chelator, food additive, and radiopharmaceutical, among other things. Recently, galactose-graft chitosan was studied as a non-viral gene and drug delivery vector to target hepatocytes. The aim of this study was to investigate the usefulness of nuclear imaging for in vivo evaluation of targeting the hepatocyte by galactose grafting. Methods and Materials: Galactosyl methylated chitosan (GMC) was produced by methylation to lactobionic acid coupled chitosan. Cytotoxicity of $^{99m}Tc$-GMC was determined by MTT assay. Rabbits were injected via their auricular vein with $^{99m}Tc$-GMC and $^{99m}Tc$-methylated chitosan (MC), the latter of which does not contain a galactose group, and images were acquired with a gamma camera equipped with a parallel hole collimator. The composition of the galactose group in galactosylated chitosan (GC), as well as the tri-, di-, or mono-methylation of GMC, was confirmed by NMR spectroscopy. Results: The results of MTT assay indicated that $^{99m}Tc$-GMC was non-toxic. $^{99m}Tc$-GMC specifically accumulated in the liver within 10 minutes of injection and maintained high hepatic uptake. In contrast, $^{99m}Tc$-MC showed faint liver uptake. $^{99m}Tc$-GMC scintigraphy of rabbits showed that the galactose ligand principally targeted the liver while the chitosan functionalities led to excretion through the urinary system. Conclusion: Bioconjugation with a specific ligand endows some degree of targetability to an administered molecule or drug, as in the case of galactose for hepatocyte in vivo, and evaluating said targetabililty is a clear example of the great benefit proffered by nuclear imaging.

• The Journal of Internal Korean Medicine
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• v.28 no.3
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• pp.531-543
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• 2007

Backgrounds : Gastric cancer is one of the most frequent causes of cancer-related deaths worldwide. Gastric cancer patients frequently exhibit distant metastasis at the time of diagnosis and at present, there is no standard regimen after operation or chemotherapy to prevent metastasis and recurrences. Aims : The objective of the study was to compare the overall survival and disease free survival in patients treated with wheel balance therapy (WBT) with patients treated with WBT alone or the combination of WBT and conventional therapy and see if there were any significant improvements in survival between the two groups. Setting & Design : East-West Cancer Center at Daejeon University: retrospective study. Materials & Methods : We retrospectively analyzed 62 patients with stage III (40 patients) and stage IV (22 patients) gastric cancer who have received operation or chemotherapy 2 months prior to beginning WBT. The patients followed the WBT protocol which includes herbal medicine such as PSM capsules, OnePlus syrup, or HAD capsules which prevent metastasis and recurrences. Overall survival and disease free survival were analyzed and the patients were treated for 89.55 weeks and 49.27 weeks (median value) for stages III and IV, respectively. Statistical analysis used : Overall survival and disease free survival were estimated using the Kaplan-Meier method and the WBT and combination treatment arms were compared using the log rank test. Results : For stage III, the 3 year overall survival was 78.5% and disease free survival was 78.3%. Metastasis and recurrence occurred in 13 of 40 patients (32.5%). For stage IV, the 2 year overall survival was 18.2% and disease free survival was also 18.2%. Metastasis and recurrence occurred in 19 of 22 patients (86.4%). No significant difference was found statistically between the WBT alone and combination treatment arms though the combination regimen showed superiority (overall survival p=0.5093, disease free survival p=0.5175). Conclusions : WBT yielded satisfactory results in prolonging survival and preventing metastasis and recurrence in gastric cancer patients. The major treatment unit of WBT is composed of herbal medications (HAD, PSM capsules, OnePlus syrup) and a randomized, prospective study should be carried out using only this treatment unit in the future.

• Journal of Haehwa Medicine
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• v.4 no.2
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• pp.255-272
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• 1996

소적백출산(消積白朮散)은 ${\ll}$화제국방(和劑局方)${\gg}$에 삼령백출산(蔘笭白朮散)에 정열해독약(淸熱解毒藥)인 와송(瓦松) 금은화(金銀花) 포공영(蒲公英)을 가미(加味)한 처방(處方)으로, 본방(本方)인 삼령백출산(蔘笭白朮散)은 비위허약(脾胃虛弱), 음식부진(飮食不振), 다곤소력(多困少力) 중만비대(中滿痺臺), 심정기천(心柾氣喘), 구토(嘔吐), 설사(泄瀉), 상한해수(傷寒咳嗽)를 치료목적(治療目的)으로 쓰여 온 이래(以來) 임상에서는 대편부실(大便不實), 구설(久泄), 옹달궤후(癰疸潰後) 불사식자(不思食者)를 치료(治療)하는데 다용(多用)되어 왔다. 종양(腫瘍)(Neoplasia)은 새로운 성장(成長)(New+ Glowth) 이라는 세포학적(細胞學的)으로 비정상세포(非正常細胞)의 과다증식(過多增殖)으로 인해 실질장기(實質臟器), 유강장기(有腔腸器), 및 골격(骨格), 피부조직(皮膚組織)에 비정상조직(非正常組織)을 형성(形成)하는 질환(疾患)이다. 현대적(現代的) 종양(腫瘍)과 유사(類似)한 한의학적(韓醫學的)인 병증(病症)은 ${\ll}$소문(素問)${\gg}$에서는 "궐산(厥疝), 복량(伏梁), 식적(息積)"으로 ${\ll}$영추(靈樞)${\gg}$에서는 "장담(腸覃), 석가"로 표시(表示)된 이후(以後)로 소원방(巢元方)은 징가, 식일, 석옹(石癰), 완저(緩疽), 석저(石疽) 등으로 표현(表現)하였다. 원인(原因)에 대(對)해서는 ${\ll}$내경(內經)${\gg}$에서는 허(虛)와 한기(寒氣), 한(寒) 열(熱)로 보았고, 그 외(外)의 학자(學者)들은 내허(內虛)와 기혈불순(氣血不順), 화(火), 한(寒), 기울(氣鬱), 음양불화(陰陽不和)등으로 보았다. 치료(治療)는 ${\ll}$내경(內經) 자법론(刺法論)${\gg}$에서 "정기재내(正氣在內) 사불가우(邪不可于)" 이라 하여 생명활동(生命活動)의 원동력(原動力)인 정기(正氣)의 역할(役割)을 강조(强調)하였고, ${\ll}$육원정기대론(六元正氣大論)${\gg}$에서는 "대적대취(大積大聚) 불가범야(不可犯也) 쇠기태반이지(衰其太半而止)"라 하여 공벌약(攻伐藥)을 과용(過用)하여 정기(正氣)를 손상(損傷)시켜서는 안된다고 하는 등 부정위주(扶正爲主), 거사위주(祛邪爲主) 혹은 부정거사(扶正祛邪) 겸용(兼用)의 방법(方法)이 혼용(混用)되고 있다. 현대(現代) 서양의학(西洋醫學)의 항암제(抗癌劑)는 치료효과(治療效果)는 우수(優秀)하지만 악심(惡心), 구토(嘔吐)를 비롯하여 골수억제효과(骨髓抑制效果)와 간(肝), 심(心), 신(腎), 폐(肺)의 손상(損傷)을 초래(招來)하는 등(等)의 부작용(副作用)을 나타내며, 빈번(頻繁)한 화학요법제(化學療法劑)의 투여(投與)로 인(因)한 암세포(癌細胞)의 약제저항성(藥劑抵抗性) 출현(出現)등이 항암제(抗癌劑)의 문제점(問題點)으로 제시(提示)되고 있다. 이에 저자(著者)는 비위기능(脾胃機能)을 강화(强化)시켜 정기형성(正氣形成)에 깊이 관여(關與)하는 삼령백출산(蔘笭白朮散)에 청열해독(淸熱解毒), 소종산결지제(消腫散結之劑)인 금은화(金銀花), 포공영(浦公英), 와송(瓦松)을 가미(加味)하여 암발생(癌發生) 백서(白鼠)에 투약(投藥)한 후(後) sarcoma 180암세포(癌細胞)에 대(對)한 생명연장효과(生命延長效果)와 항암제(劑)의 일종(一種)인 cis-platin을 이용(利用)하여 양방항암제(洋方抗癌劑)의 부작용(副作用)에 대(對)한 본(本) 방(方)의 효과(效果)를 실험(實驗)하여 관찰(觀察)하였던 바 다음과 같은 결론(結論)을 얻었다. 1. 소적백출산(消積白朮散)은 sarcoma 180 암세포(癌細胞) 이식종양(移植腫瘍)에 대(對)해 생명연장효과(生命延長效果)가 인정(認定)되었다. 2. 소적백출산(消積白朮散)은 치암제(治癌劑)인 cis-platin 치사독성(致死毒性)에 대(對)해 생존연장효과(生存延長效果)가 인정(認定)되었다. 3. 소적백출산(消積白朮散)은 cis-platin 현독성(腎毒性) 생쥐 및 흰쥐에 있어서 유의성(有意性) 있는 체중감소억제효과(體重減少抑制效果) 및 serum BUN 상승억제효과(上昇抑制效果)가 인정(認定)되었다. 4. 소적백출산(消積白朮散)은 cis-platin 현독성(賢毒性) 흰쥐에 대(對)해 유의성(有意性) 있는 serum creatinine 상승억제효과(上昇抑制效果)가 나타났으며, cis-platin의 혈액학적(血液學的) 부작용(副作用)인 RBC, WBC 감소(減少)에 대(對)해 감소억제효과(減少抑制效果)가 인정(認定)되었다. 5. 소적백출산(消積白朮散)은 cis-platin 현독성(腎毒性) 흰쥐에 대(對)해 뇨량감소억제(尿量減少抑制) 효과(效果) 및 ureanitrogen과 creatinine 배수감소억제효과가 관찰(觀察)되었다. 이상(以上)의 결과(結果)로부터 소적백출산(消積白朮散)은 악성종양치료(惡性腫瘍治療) 및 항암제(劑)의 부작용(副作用)을 경감(輕減)시키는 데 응용(應用)할 수 있을 것으로 사료(思料)된다.